The Design and Test of a Model Siphon Spillway Citation Allen, Robert Norman (1916) The Design and Test of a Model Siphon Spillway. Bachelor's thesis, California Institute of Technology. doi:10.7907/9cr8-0033. https://resolver.caltech.edu/CaltechTHESIS:07162024-214102543 Abstract No abstract. Item Type: Thesis (Bachelor's thesis) Subject Keywords: (Civil Engineering) Degree Grantor: California Institute of Technology Division: Engineering and Applied Science Major Option: Civil Engineering Thesis Availability: Public (worldwide access) Research Advisor(s): Unknown, Unknown Thesis Committee: Unknown, Unknown Defense Date: 1 January 1916 Record Number: CaltechTHESIS:07162024-214102543 Persistent URL: https://resolver.caltech.edu/CaltechTHESIS:07162024-214102543 DOI: 10.7907/9cr8-0033 Default Usage Policy: No commercial reproduction, distribution, display or performance rights in this work are provided. ID Code: 16555 Collection: CaltechTHESIS Deposited By: Benjamin Perez Deposited On: 16 Jul 2024 23:54 Last Modified: 16 Jul 2024 23:54 Thesis Files PDF - Final Version See Usage Policy. 24MB Repository Staff Only: item control page

THESIS The Design and. Test of a model Siphon Spillway. by ~Obert ~Jorrnan .Allen Class of Nineteen Hundred Sixteen Department of Civil Engineering . THROOP COLLEGE OF TECHNOLO'.iY Pas ad ena, Cali forn ia. 1 ~16 The Design and Test of a Model Siphon Spillway. Part I .. Design. 1 2iphon Spillways. 2 Advantages of Siphon~. 3 Reasons for Test. 4 Design Conditions. 5 Possible Solutions. 6 Calculations for Design. ? Conw,ents upon Design. 8 Photographs and Drawings. ?art II .. Tests. 1 Object of Test. 2 Apparatus. 3 Method of Test and Formulae used i~ Calculations 4 Conclusions. 5 Test Data and Curves. 2 Part 1 I Design. Siphon Spill wa;y-s . Siphon spillways date back to at least 1870 when a steel pipe siphon, with a pneu.rnatic ejector, was used at a dam near :Mittersheim (Lorraine) to supply water to an irrigation ditch. Perhaps the siphon prin- ciple was arpli~d to some similar installation before that but we have no records of anything earlier. In this installation the six inch ejector pipe was brought into action by a definite hei ght cf wat e r--tbis ej ector rE;moved the air from the larg e 2'-6" siphon and brought it into siphonic action. Due to freezing and to becom- ing filled with debris, this small pipe was not satisfactory. Siphons without ejectors were erected almost contemporaneously by J. Heyn, a civil engineer of Stettin, Gerrr,any, ana_ 1:iy ~vlr. Jrecotti, an Italian eng ineer, at Mo rtara in Northern Italy. A t~pical sec- tion and short description of the two types of deEign is found in Plate I. The action in the case of a sipho n without an ejector is this:- As tte water rises it s eals the upper Jip of the air inlE;t (or pertaps the mai~ water inlet). This complet e ly seals the Ei~hon since the lower or discharge lip is also sealed slightly. A further rise starts a stream over th e throat of the si.phon--ttis stream entrains air e.nd. e jects it under 3 the discharg-e lip. The air being slightl;y rariiied iLsid e the sipho n , the water rises hi gher, a bigge r strec:im goes over the J.i1J-- more air is ejected and in a f ew seconds the siphon is running tull. As soon as the water falls below the air inlet the s eal is broken and the siphonic action stops. Siphons on this prin- ciple were euccessful and a number were put in servicE-, some in streams to prot ect power plants from floods as at la Praz and Largentiere, f rancc, some as s1;i llvva;ys for canals or power dams, and others in irri gati on ~rojects. i, few ;years later the first siphon spillwa;fs were constructed in America, amon g the first be in g a battery of siphons in Arizona on the Salt River Project of the United Stat es ?e clamation s~ rvicc. (See Plate III.) This battery ~fa thousand second-feet capacity was d~si gned under the dir ecti on of ~r . Louis consultin8' er.gineer in Los An ge les. a. Hill, now a At about th e same • five s1:pc.ons • , ' t a lJ.e d upon t,,_,r,e a b a tt . e ry o 1· ~ was ins t 1me YW!1a ?roject of the '::r .S. F .S. This battery ( see P late III) had a test capacity of over fifteen h1rndrcd second-f'e et a.s is sh own t;y :Ca ta Sh ect I. ?r o1iaL ly b ei'ore loth of ttiese, in abo',i.t J.:)OS , :.:r. Geo1-ce :r; . Sticlme~; , Supervising :::n 0 ineer on the I:"l ew York State :Barge Canal, inst a 1led 2 . number of siphon spillways on the :3arge Canal and pat ented his designs. Aiter the 1emarks about European _pra.utice it migr:t be int erei::tinit to quote from 4 the '' Ear3:e Canal BullE:tin" September 191G. In rei'er- ence to ttE: Barge Canal spillwa;ys, "It is believed that in them the siphon principle is· used for the first time to create & spillway of any considerable cize. The siphon action will be entireJy automatic, in bott the starting- and the sto11pi:r.§.· of tbe flow." ?art of the above quot£.,,tion is evidently basecl upoD a lad: oi knowledge of Eurpp~an installations. Ttis prior use would probably invalidate the patents if a test case were made. Whereas the largest battery on the Earge Cahal had only seven hund.rEd ancl ten second-feet capaC;i t;y· , the later de~elop~eLt ty the Tennessee Power Co. on Ocoee River had a twelve hundred s econd-feet c apa~ity. These were desi gned. und.er tbe ~.tickney ratents l:.nd are described in the Engineering ~ecord of hla~ 16th, 1914, paee 567. A section of this spill~ay is shown on Plate II. Be- sides these, tberc have been only a few ether siphons installed in the Unit ed States end t~er e is no information available u1,-ion tr.er:: a.t prE:.sent. 2 Advantages of the Sibhon Spillways. The advantages oi the siphon spillway were early reco gnized. The disadvantage of the ejector in a cold climate wes eliminated b~y tte automatic siphon. '.L'here was fear at first that the automatic siphon would freeze up but this proved grounc'1less since in actual operation the siphon was much less liable to freeze and refuse to 5 opera te than any typs of automatic or mechan ically operated gates or equ:ipr1e11t. The dan ge r of becoraing clogged ty ice or deb ris was no greater than in the e:ate t;ype ot' s:pillwa;y . '.!.1his danc;er is usuallJ elirr.- inated b~' having a small overflow spillwa~ i:f an;y amount oi aebris must be permitted to pass tbe dam, by screening the entrance to th e siphons, b ".:J putt inE; the u-:trance fer enoup:h below the surface to prevent tl!e entrance of debris, or b;y a combination of al l three meth ods. If this i~ ~one the siphon is more reliable than any equipment other than the ovtrflow The second anu prcatest advant~ ge is the g1·cate r 0uantity of water ~hich can b e controlled in the same space with tbe same variati on in head. :riconorE~- of f:ro1md space arid also of ccr..~truction cost resi..:Jts en any siphon installation as compared with the overflow spillway. This is p a rticularily evident where a small variation in head water level is requir6d either by law er by the naturE of the installation. The reasori for the abov£ statement ie seen when the faut is known that the head available to p r oduce velocity at the crest of the overflow spillway is simply the depth of water over the crest , whereas the lead a vailalle to produce velocity in th e throat oi the siphon is thcoreticall~ tte difference in elevation betw een bead water and tail water surfaces ( tbougb rcot c:xceeding thirty-four feet 6 which corresponc1s to a vacuum in the siphon tube J • from this it is seen that the smaller the a llowabl0 vari&tion the l arrer tLE: 8dvant egE: is for the siph on spill wa;y . See P l ate I I for a de :fin it e cornpari son bc- twc cn the overflow and the siphon spillway. For a sma ll o.eyith of vvater on the cr<::st the overflow bpillway wi ll have to be from ttre e to ten times the len t th of the sipbon spilli,vay, which can .,;OntE"i.n a batte:c;y of siphons designed especially for small hea d water variations. This mea ns aver~ great savine in construc- tion e ast . Also, the siphon spiJ.lway is particularly aa.e.pt ca for i)l aces where a long sri.llwa;y is impossible be cause of topo g raphy. Another aJvantnfe lies in the quick respons0 of th e siphon to lar f e variations in quantity, u necessary ttin f for rower plant jnstslletions. The ad vant~ ge of the siphon spillwa~ over metal gate s , automatic or mechanical , is not so marked. The siphon has a smaller first cost and as 01dinarily a dam mus t be built anyhow--it is much cheapLr to build the siphons into tte Jam than to construct some elaborate sttel gat e s and or crati~g equipment. In addition, the siphon re0uires less ma intenance and att~ndance, and if properl~ desi gned will probably c ive better service. 7 3 Reasons for Test. Althou.g·l1 siphons have ocen built for a number of years in 1.Jcth Eur9pe and I~itcd ftates, nottinf deiini te seems to be known as to th: governing the aesign. exact characterist1c.s rfo vcr;/ good test data ai e available in ~ither continent and even what can be found is general and not specific in nature. The form- ulae used in calculating a siphon are those ordinarily used in bydraulics:0, Where =AV C~ = ac ✓ 2 gh V = velocity in ft/sec. c = a constant. A = ares, of smallE.,st cross-section, usually the are~ of the throat. Q = quantit~' in cu1.Jic feet 1,er ;:;econ.d. Tr,is constant ''c" vrnuld naturall;y var~y witb both the shape and the material of the siphon. It represents the efficiency and varies from .45 to .80 in data available, for which see drawin~s and test data. Outside of this 3eneral totul efficiency no other iniormation ie avajlable. All siphons have tetn dE- signed on the 5encral principleE of hydraulics--the one lranch of science ~h~se formulae alwa~s contain ucnstants which have to be dete1mined b~ test. Uotbing is known of the relative he~d losses in the various parts of the siphon:- the entrance; the ttroat;;the vertical, 8 overhanginr , or sloping ( 2own spout); or the curved. ,:: isch a1·c0 end. Nothing , beyond a muuh expr e s s ed op ini on , is known of the effect on effici8ncy of sharp ed e es on the inl e t and d isch ar ge lips. The effect of the depth o:!. sulwnersion o:f the dis c har e:·e lip u._po.n both SfeLd in priming 8n<'l. on t h e total e:f'fici enc;y is unknown. Another "Lcnknown relation is that between the d epth c i Viater running through tbE throat Emc1 the speed. in fJYiming, witt various t 2il water elevations. The eife~t on efiiciency of e contracting or an enle.r c inf section is e lso un:~;novm. Thus these va rious points s eem to have been ne glected in the d e eire to obtain the ov erall ef ficiency. ?bis rr &c - tice seem s strange wten it is considered that sometimes a very sli ght change in u part oi a hydraulic machine will ~ake a g reat chan f·e in tfiiciency. Such a prac- tiCG of aesirn or t est i8 n ot danaeroue since the siphon ~ ~ spillway wi11 work satisfactorily under & greet variety of conditions, ~hereas the overall efficiency is all that need b e known to satis f y any guarantee as to performance. This method however, does not help in mak ing the most econornic&,l dEsi gn or in making a dcsi gL to satisfy so me additional Sfecifications as to speed in bringing int o operation, or as to a c ertain allo~able variation in heaa watsr. All this sreat lack of val- uable data lea vEs a ~ide atd interestin g fi e ld for test-a field, which so f ar as the ~riter h a E been able t o f ind, has not beEn investi ra tea. 4 Design Conditions. ~ 1th tte decisio n made as to the dE.:sirabilit~ of me.kine and. testin g a model si_pton spilhva;;, the Jirst cons id eration w~e th e plant evailable. ~hE gene r a l a.es igT.1 oi the hydraulic laboratory and u~uiprncnt is shown in Plate V. The quantity available fo r continuous flow was about a maximum oi three sEcond-fe et . This couJd be furnished h~ the ce ntr if ugal pump a nd the quant ity rn eE:. sured direct on t l-1 e 6'' venturi me t er. :-lo re water (p e rhaps one second-feet; was available if some other method of deter:nining quantity was us ed . Atm,.dance of storag·E.: capaci t:y was available in the two cist erns, one six by ten by fo urteen, th e other nine a~a a ha l f by fou r teen t y fourteen. Tte centr i j u6a l could pump irom either the 1e r;re or sma ll ci s t ern wh ereas to tb s te c::i.n &. i-:d piston purn:ps must take v:atcr from the Emall cistern. A roof tank two by four bJ ei ght was available for a sma.11 amount o:f s tora f· e, pri:r:ci_pallJ tc have water to prime the c~ntrifuea l. Extendin g from the steel fres- sure tank wa s a concrete t ank two 1 by tw o and a half,by thirty feet 1ong , with rates end a pipe Je ad ing hack to the SKall ci s tern. The co nditions i mpo s ed by the nature of the te sts des ired were; -1 - A number oi· ,nod.els, or else a mod. el wrosc shape 10 could be easil~ altered. 2 - Light weight as possi"l.Jle. Z A satisfaotor;y method of attachine- tubes for water or mercury columns to determine head at the va:rious points on the siphon. 4 - A model with the friction or roughness coefficients the same as for the material used in the construction ofafull size siphcn. 5 Possible Solutions. There were at least three possible solutions of the proolem. First method f,. small rr.od.el d.esigned for two and a half foot head, to be built of thin reififorced concrete (wire lath reinforcemfnt). This model to be plaoed in the concrete trough and water supplied b;y· an;{ or all three pumps. Second rr;ethod A special metal-Jined wooden tank to be constructed, fittea with wooden baffles, and set up at any desired elevation aoove the concrete tank. The water to be sent throurh tte steel tank and a beavy canvas pipe up into the wooden tank. The models to be built of reinforced concrete or if preferred, of heavy galvanized iron reinforced for both internal and external pressure. Any or all pumps to be usE:d. 11 T·hird method : A hole to be cut through the con- crete wall between the two cisterns with a special dam fitted for connecting the models. of· either concrete or metal. The models to be made Onl;y the centri iugal pump available for pumping. :Jetbod I 1he advantages of the first method were as follows:first, small models easily and cheaply constructed of concrete since the whole interior surface could be reached; second, all ~ork out in the open air with consequent ease in reading water columns or gages ana_ in making an;;- necessary adjustments to gages or to the model itself; third, fairly long approach and discbar r e bed available and consequent close approach to an actual C;OLdition. The disadvantages werE:- first, too Jow a head to get enourb velocity to note differences where small change·s were made; se:cond, the variations oi tead and tail water levels would be all out of proportion to the accuracy of the readings of interior points I'i letbod - - - -II -Advantages:- i'irst, a h1J;hEr heaa. than method I t.(..w1.1ld k available, in fact any head desired could be obtained b~ raising or lowering the water in the concrete tank into which the model discharged; second, all gages, etc. would 12 be at the correct level for easy readi nf ; third, every.,_h. wo.uf✓ he th e open air . wlrll .,~ consequen t. . v ing r-e in · :1:7' ease in react.eh. ing fages, rnakinr changes in model or set-up; fourth, II either concrete or sheet metal ~ould be used with equal ease; fifth, one man operation is rossible. Disaivantages:- first, a comparatively small wooden tank would have to be rnade, and with the 2:reat entrance velocit;y of' a three second-feet quanLit;; it is doubtful ho~ quiet the water could be made by any nuffiber or design of baffles; second, tb s e~it pipe from the steel tank is so small as to overl_oEid ._the motor d.ri ving the centrifugal pump if three seuond-feet were forced thru; third, a costly tank aLJ model are necessary; fourth, the tank and model would likely have to be disturbed frequentl~ for class work. :.kthod III i1.dvantages: - first, all apparatus set up could be left in place an indeiinite time without being disturbed; second, a large body oi water at both Entr~nce and disch&rfe ends woula aid in keeping tte water quiet and consequcntl;:,, give more acc:u:cat0 reading:s o: the total he::i.d; third, rnoft oi the '..;ater could be sent dowri the turbine dnd. t tube ancl tbe:n. fore cause no splash; fourth, concrete tunk available for store ge and for slow discharge of a small quantity; fifth, cheaper method than method II. 12 Disadvantages:- first, a bole two foot squa1e would tave to be cut in twElve inch concrete and several scaffolds would have to be erected; second, poor light and air due to almost completely closed cistern; third, inconvenient method of getting in and out of the large cietern ana of gettin g the model in and out through the small cistern; fourth, only the centrifugal pump could 11e used.; fifth, two mun op e ration or else a great number of trips in and out of the cistern necessery. Consideri~f the ab ove advantages and disadvantages alon g with the fact that ti ~e an d accura cy were more important than any other considerations, me thod I ~as elim1 inated on account of the pr~ble lack of accuracy of results. 2c thods II and III were very equal but it was finally decided that the probable greater ~c~uracy and the abilit y to leave th e ap~aratus set up ind~tinately in method III outweighed the advantages of method II. It v,as aft erward found that the results obtained would have been al most im1ossible baa either oi the other methods been used. Concrete and sheet met a l were both consid er ed as ~aterials for the construction of the model. Concrete t nd t b e advantage in tt&t it h e d the same friction constants as the full size siphons, and also the advant ag e that it required no special br ac ing to keep the model from bulg ing or collapsing. It had the disadvantages 14 that it was heavy and liable to crack and develop air leaks, that it was diJ±icult to make a satisfactor;/ connection f"o:c the tubes for the vwter columns, and that a number of models would have to be made . .Another ver:., im:porte.nt disadvantage of concrete v:as the time which would have been necessary to construct and cure tte models. This time waE not available. Sheet metal had the advantage in that a design could be made wb ich migl:t readil~- tc altered in. shape in one direction, that it was light, and that very satisfactor~ water co]ur.r.n connections cocld be !nade. Its disadvan- tages were higher cost, end the fact that heavy setal with strong side bracing was required to yrevent bulging or collapsing. .A £'Teat di saa_ vanta,ge tor sr eet r;-,etal was the fact that the frictio~ constants were different from concrete ( al ttnut:-h relati vcly tLc same i'or uns group of medeLs). The relotive losses were tte rf:ost importrnt however, in the propc~ed teEts. From the above reasons it is evident t~at ii time were available, a more truly representative test could probably have been made with co.nd"ull;y- con::,truc-~ed concrete models. However, since t1mt ~hS aver~ imfor- tant consideration, the sheet metal was used for the model. 15 6 Calcul½tions for Design. .iiven quantit;/ available - 3 se(.;/ft. 1 Lssurne a 7' bead. 60'/o efficiency. IT Formula Q = 3 Q, = Ac 12· gh ' Q = quantity. A= area oi throat = • 60 C A or area of throat= Q c ,./ 2 gh h = head 3 A = of . g - acceleration grav ity, Z2.2 . 60 X 8.025 X ,{1i c = efficiency exp . as a decimal. 5 = 8.025 fT = -2=:.~6'+ . z.. .? (:, tt 2 = 34 in? To allov1 for a higher ef'ficiency a section 2} 11 x l G')ll t equal to 30 snua£e inches in cross-section, was chosen for the throat. ~ith this as a basis and seven foot as the approximate head, the design was made as s1:own on Ple.te IV. Some e:x.j;;lanation is necessary as to certain fee.tures of the design. It wac d.ecidea that a uniiormJ.y enlarg- ing cross-sectior. of the downspout wou.1d be used at first, the size being cut dovm in steps to a uniform and iinally to a converging section ior different tests. This could best be acco nrr,listt:cl b;y having the r:cction as sho1ivn, a form which could be e a sil:v" soJderecl or loosened, and uh ich would leave a smooth surface inside (from enlarge~ 16 to contracted section). The edges of the top and bottom plates viE,re turned out about 5/ 'e" and cut wherever necessa.ry for curves while the side plates .extended a minimum of 7/8 11 beyond the inside line of the siphon, thus leaving at least 1/ 4'' clearance to aicl in running the solder under the edge oi the plates. The collar around the throat of tr1e siphon is des i f-r1ec1 to fit against rubber flaps on a wooden block cut to fit the siphon and the iron frame in the concrete wall. This prevents excess leakage y;hen the r:e8d water is above the dam. A detail drawing of this connection and the top support of the model is shown on :Plat e V. The water column connections, 11 in number, are short 3/8 11 brass tubes soldered. to the side of the sir,ho'n or. tr.e_, _c;.1.;,,. of the section. The holes were drilled. to the exact inside diameter of the tube anC carefully filed, flush with both the inside of the tube and the inside of the siphon. Such an arranfement would. give the true reading of the r ressure at the point of connection with the siphon. The joints at the top of the body oi the sirhon wero necessary due to the size o:f ~,tock aLcl were rnade as smooth as possible on the inside of the siphon. Those in the side plates were rivited (and soldered) lap joints while those in the upper and lcwcr plates w~re the ordinary rolled join~s. 17 Straight lines Wbre used wherever possible in the design to facilitate th e bending of metal and the ease of construction of thE, model. In the completed mod.€:l a mistake had been made as to the spacing of some of the water column connections. Just how well these and other dimensions check with those of the design is shovm on Plates IV and V and Data Sheet II. !twas expected that braces would have to be placed on the broad faces of the model to resist suction in the upper part of the fuodel and to resist pressure in the lower part. A first test proved that this was necessary so eight braces spaced about six inches apart and composed. of bent-up "T's" were soldered upon the upper 2/ 3 of the model as shown by the photographs. The lower 1/3 was braced on the sides by two boards bolted across the model, one extending to the' bottom of the tank as a support to the siphon. With this arrangement the model proved entirely satisfactory. The total cost of labor and materials upon the metal model was about twenty-two dollars ( $22.00). CONCRE.TE.. TRN/'\ 30"><3_,",.-,;;' ...SIPHON f)El1Rlft(; ON 1:JL.OCI<. ' MODE../... BEFORE BRACES WERE ADDED The fwo Sltf«I/ yods shown at aoowf .f.: wa.lf wp fhe p,ctl./re were u.sed fc chmp holifrds ft> fh~ side~ of f/Je s1pJro11 -Ir, prevent bulrmq (tn lt>wer flttrd). One board exfenr/ed fo the btJftom of fhe c1sfer1t n luff Ct/Ir'( fhe J()ffflrf of ihe s1phcn. MODEL c.5/PHON RERDY FOR IMSTIIUATIOM INL£T SIDE. This shows the -11_ J,mces w/11ch wer-e odtled m the Jttot:/el fo prePehf co/'4pstnq dwe fo -llte presswr~ JJ~mq below oftlfosphenc ms1cte of th~ .s1pho11 when m acf1011. MODEL .5/PHON READY FOR INSTALLATION Dl.5CHARGE .5/DE. 'JJoffpd Imes .sholtJ Cfffnx,mafelr ihe shape of fhe dtscltrwqe /Jp {Dy Models I'Y JI. Th~ p1cfwes shol() Model I . MODEL SIPHON WITH GAUGE.P.NDBOARD .5£.VERAL WllTER COLUMNS ATTACHED 18 Part II .. Tests. 1 - Object of Test. The deiinite objects of the tests W81·e to deterKine the iollowj ng :1 - ~he relation between the depth of sub mergence of the discharge lip and the c3 ~pt t of v.a ter over throat to bring the siphon into action ~~der various air inlet conrlitions. 2 - rrhe reJation between the d eptr: cf sutme:n;:: ence of the dischar re lip and the speed in primin f with various aepths oj water over th ~ throat and various air inlet conditions. 3 - The relative and act~al head loot in various portions o f the siphon. 4 - The efieat of vurious shapes of parts of the cj_phon up on head. lost in tL h. t _part and upon tbe t c tal 5 - The tot e l eijicienc~ of the diiferent &haped models, i.e. the constant 11 c ' in t'ne :fo r mula 1 C, = cA ✓ 2 gh. 6 - An~ other rel a ti uns 0hioh mi ght teaome ap1arent c"i urin,.:.: the test. 2 - Appa :i:cctus. Plate V stows tte fOsit1 cn of ttc mo del durin f the test. The inlet end of tte siphon extend~a over t he dum into tbe s,r:1:~11 c i stern . i~ su2:i;:; en d. 1.od rlati"orrn v,as "built in this cistern for use in placinc and removing the model. The discharge end, ull water columns and scale.board were in the large covered cistern. Here a platform and bench ~ere built above reach of the ~ater. The photographs show the water column connections and the scale toard. to which the tubes were attached. e.nc1 contents Vi hen l'lin ning The Vieieht of the siphon was carried part 1l by the throat resting upon tbc dam as shown in Plate V, &.nd partly by a wooden brace bolted to the inside oj the siphon and resting on the bottoffi of the cistern. Tiater co 1 umns were of 5/ 16n glass tubing connected by 5/ 16" rubber tubing to the plugs on the si1ihon. Thet, e tubes were suspencled ty strin?S fror.i nails oi, tl:e scb.le board. The connection was made ajustable b~ having_ the strings under a rut,ber band ( start 1iiece of tubine::-); the stI"inc.:;s could be lengthened or stortenea b~ pullin1 them throu6h the rubber banc1 or the rub1:,er band could iis~li be moved. At seve r21 points water columns could not be used because of 'pressure r.eaa_s lcwer t1ian atmos_p1ieric (i.e. the water column went below the surfece in the t~il water). At these points :iu" tubes o:f mercury were used cm several tests and later tteEc were repl&ced by inverted water uolumns whioh '.!iE.asure(1 tl,e pre::.sure 1,elow atrnosrJteric directl~ in feet of water. ',''.nter tor the test v:as supplied by the centrifuJTl pump c1 riven by a twent~.,- horse power, direct connect eel D. c. 20 motor with adjust t·ble field control and therefor any desirec'. speed within quite a large range. n,eo..snrul directly on an line. Ae The guantit;y was e" Venturi rr.cter in the 8" pump much water as possible ~ac sent ttro~i h tte turbine craft tube, the rest 6 oin g e. round tbrout b tht concrete t::rnk and ;;&ck ir,to the nna.11 cistern. All rur.;p- ing was directly from the larRe cistern (tail water) through the Venturi meter, anrl into the st0e.ll cir.t E: rn from which it vms dr e v,m lJ;:,· the siphon. '':hen S!Dall r! uantities wEcre d.esired tr' e concrete tank was fiJ1Ec1 t:nd slowl~ dise;hP.. rted. 'i.11, e a.rwu.nt of tlowiT, f' (altr:ough not desired in any tests ma de) could be calculated by the kn e: vm time and t'be c1. roi: was at iYl v·.ater level. It first feared thr:.t trouble i:r: m1_0.:dng an exect de- terminat ion of tLe q_u&ntitJ' :flowing tl:rouct tte siphon mi ght I't: Sult throu2.·h the stittin g- c:f storE;.ge from one ch,tern to the ot11er. i'bis fear froved croumlless lie- cause tte very rafid and continuous flow caused the ~atcr to quickl;:l ae~cU..'Ile a h :vel V'ihi0h remained constant. A later aadition to the equipment was a ~mall a ir valve att1:; cr. ec1_ to tube ( 4) to 1 et o a L L"; ; e ai:r <:,n tr1:,. ined in the siphon t;y the rise of wa.ter--s1rntting off automat ical 1;y as soon as tt e suet icn started. Another acl..d- it i on was a ~ate over the inlet opening whict could be opened at will. '.l'his was sirnpl;y a weighted. board with rubber flaps to help make a :fa.irlJ' -.; mter tight ;.:"ate:. 21 ('nl;i one sli ght change was maa e in mode l I, but the alte r ea mode l was called model II. Referring to Plate IV it wil l be seen that the discharge lip was to extend 4" be;_)'ond the last tube (11) en the siJJ1:0n. th is was a·bout 5 1' . J,.ctuall;y, .AJ.so , this liI; was suprGsed to lJ e level :f ro m point ( 11) out to the ed t;e. '.!.' bis actually sloped d ownward &bout 3/8 11 in t bat distance. Thus, due to the shape of the lip, any entreined air i n the eipton had to be cerried down 1.7'1 and out about 8 11 from the edge a t tube (1 0 ) before it con1d escape. '.i:'"r.is vv~s in P-1od e 1 I. In model II this l i.p ·,,as unso ld ered. lJack t o t he b er.. c, a nd bent up en a l ~/' radius. It then exactly re, - s emli led the discta r g·e lip shown in the · lov,er section on P l ate III. Ent r e inea air in this case wort l d only have ed'le ..+ to be ca rri t:d dov,n 1-1/ 8!! and over 1-5/ 8" f ro m theAtnbe (10) to be released. It will be noted in th e test data that no reading is giv en for tube (11) on ~cdel II. ih iE i s due to th e f act that tt~re is no section for ~hich t tis m&~ be ~onsidere~ a c enter. 3 Methods of TeEt and Formula e Vsed . rrben: were Jo t.ff a. ir i nlet cor:::I i ti ons under wt~ct tests we re desired tc show the rela tio ns steted in ob- jects i and 2 . These we re:- one tube (Jo.4) open , one tuhe open unti l t r:e 7;atcr start::: over tbe tr:roat, all 22 tubes closed, and lastly tube (4) fitted with the air valve a bove-mentioned. The first of thes~ would be the ~quivalcnt of any siphon where an air vent waE left open continually. The J.ast would be similRr to any siphon where this same air vent was fitted with an a i1 valve to prohibit sucking air. Th~ second, with all tub 8S closed es Boon 9 S wat er starts over the throat, is the equivalent of pr~ct icalJy all siphons yet cons t r ucted since a lmost all s ea l just as . soon t".S, or shortl~ a f ter, the vmter st&.rts ove 1: tte throat. The third, with all tubes closeG anct the inlet lip extendjnf down into th t ~ater is illustr&ted by the section Figur£ I, flate I, a nd by tr,e s e ctions stovrr. on :? lat E: III. These on ? late III, however, do not work upon this prj nciple since they tave an adjustable ste·el inlet (not srow1'l on c1 rawir;p:s ) v,rich with a smsJl ejector uttachment, enables the siphon to be pri med a t will r eea1d less of the he 8d water elevation. Method of Teet for Object 1. The ~r ttod of test to obtain the relation bet we en the d eptb of submerrence at the a isc:-:arg e lip anc. the depth of wa t e r ave~ throat to brinf the siphon into iull action wa2 to let the water out slowly f r om the concr ete st ora ~.::c tan1,, ttur uausir:e a g-r ad ualJ.:, i.r, cr8asin c· depth 0 c f water ev e r throc.t. r.rhen, under one Oi the otter oi th e conditionf' namer"1 above, rca d ir: g-s of be ad. water elev et ion (li.W.) and tail water elevation (T. W.) were t ake n :lor tte condition at whicl:. the sipton fY1i1'.'ed. Knowing r • r:z. Gu the gafe rea din g for tr.e ed ge of tte throat and for the disch &rgc lip (see Data Sheet 2) the depth over thro a t and the dept h of sut ~~reence of the discha r ge lif could be found. The resµlts we re p lotted 2nd as th e c urves t ook shape, special po i nts d esiref cou l d t e t ake~ and the C;Urve i i11ed out. Ln~1 wtere frorn on e to iive or more n oad ing·s could b e t ake n befoH tne eoncrete t ank nefded to be rc:filled. .Sata t ekcn r,:,;- t'r'is rnet r. oa ur,d curves obtained are shown on Da ta Sheets 2, 4 , and 5; a nd on Surve ~heet 1 for mod el I .s.nd upon :9s ta Sheets 8 , 0 , 10 , 11, and Curve 3heet la for model II. ~.;ethoa. of 'Ie st for 01 j ect I I. The method of t fs t to determine the rela ti on between tr:6 de:.:p t h o:f s ubrt1e r p en ce of tr1e n is c tar ; ·e lip ana the s ree a in rri min ~ ~it h various dtp the oi water o~ e r tte thr o at was a l most the same as ior Object I. ~he on ly differcr:ce v;as that tt,e inlet gate v,a s c l J se d ur..ti1 tte ~es ired deptt ovc1 ttroat ~as relched and the n OpLne d , the tim . ic p rimin g being the only additional r&adinf. Re ,s:, i iri[S were only tak Fr. under two o:f th e air i r: lE:t con cl i tions, t1-iat of one tube open and th at o:'. 811 tubes closed as soon as the water st ~rtea over t he t hroat. A rriettoa used to some extent ~ under the cne hole open condition was to blo w back int o the sip~on, t his extra air keepinff th e water from coming over t he throat until the desi r ed H. ~ . el evation was reached a r..d th e tube opened. This method proved to be just as satisfactory ena. gave the sarr.e results as that of opening the inlet f E.te. For all r eed ings under the closed ove1 thrcut cond it i c n , t ub e ( L~ ) vm s n :i t c 1 o s c::i un t i 1 t b,: :f i rs t ti i ck 1 e ~f water over the throat was teard. Thi~ took ~lace ~t a sl4 gt tly higter ( . 00 5') reading th&n tLc gage rE.:adi1:g f or t h c Ed c e o f t b e th ro at . Data taken l ·~ t'bis mt:;thod and 0 :.:u·ver:i obtained a1·e shown on Data Sheets 6 und 7 8.nd on Cm ve Sheets 2 and Z for rr: odc l I, and or1 Data ;3h eet s 12 and l Zi an d on Curve Sheets 2a and Sa for mo del II. 3 Me thod of test for Objects 3, 4, and 5. These tests required that t~e siph on be run at full capac it~. This proved to be almost i npos sible since the actual efficiency of the model (expressed as indicated above in the design) v:as a·bout 1.4 ti mes as large as the 7070 desi1:n efficiency. 'Ihils to suppl;f tte required quan- tity of water through the small pipes, the motor driving the centrifugal had to be heavil y overloaded. Such a condition made it imperative that the teFt last no longer than 15 or 20 ~inutes witlout great dan ger of overheatin g the motor. To balance this, however, it was found that the quantity of flowing w&ter re mair:ed constant and that a condition of equilibrium was quickly establish ed . The open,tion was as follows;~ the pump being started 25 and the sipr!on running full capacity, the water colunms were tested to see that they were fu ] l of water or air as tbe ca se happ ened to be. Tte inverted columns, ~suck- in g" water from the T. ~ . level, bad to be lift ed out and allowed to completely fill with a ir. Then, by pinching the rubber hose, tt.e tubes vvere graduall y allowed. to fill ~itb water to the height re gisterin g the pressure head (b e low atmospheric) at the point of attachment to t h e siphon. With all columns in workin g ord er, reaa_in gb of quantity, H. W. and T.~. levels, and gag e heights of all water or mercury columns were taken . .b.11 tbe~ c were checked one or more times and when a small differenut Tesult ed , the av e ra ge of the readings was taken as f inal. were t eken. vd.th b oth "U" mercur~ tubes and witt irverted water columns on !fo de·l I v·ith several different heads and quantities. The data and the calcula - tions ther efrom a1'e shown on Data sheets 14, 15 and 16 for Kadel I and on Data sheet 17 for Model II. Only one test of t h is t;/p C was run on }.lo del II due t o lack of time. The head losses and the total efficiency were calculated from the ex1ierimcntal data in the fo ::. lo wine manner: Le t A= the cro ss - s ectiona l area in s quare feet of any s ection as de termined b y careful mea sure ment. See Data Sheet 2. V = the velocity in ieet per second at any section. Q - the quantity flo wing through the siphon expressed 26 in second feet (cubic feet per second.) . r, \J = the gage reading for the point itself--see D.S.2 R = the gage reading for the water colurr:m at tbe point z = the height of centt:r of section in question above some ass u.YIJe d. elevation, in this case tube (1 0) whose gage r0ading was 7.00. H = the total head to produce velocity ( d ifference in elevation between headwater h. W. and tailwater 1. ~ .) c = a constant= the efficienc~ when expressed as a per-cent. g = the acceleration of gruvity = 32 .2 p - pressure in lbs. per sq. ft. = pressure head in w weight of water per cu. ft. feet at section. Knowing A and Q, Vis found by the equation, Q. =Av. Also from Bernoulli's Equation of the conservation of energy _and continuit;y of flow press. head 1 + vel. head. 1 + static head. 1 = press. head 2 + vel. heed2+ static heaa.2+ lost head n v2 2g ::..l+ -1+ .CJ1 r:1' w -- ~ + V~ t L,2 rr + L OS t h ea d 2g w iJow P :for any SE:ction with a "U" water w -~ lcolumn = ~✓i = G ~ n , E beine: the lar ger ~ / j 1 since O on the e;ag e is at the top. This ~ ~ p _tR_,~ means that tte value of w iE- negative ~ for the c &se shown. 27 For a "U" tube; of mercury tte value of P - (for negative prssures) G - R, vv where?= Gage readinf S ~ 13.59 x O. tube , water column ( inverted) p = t w Substituting these values--tb e value of P + v2 w 2g wa.s found for eacb sect ion. + Z Tb e c1i ii erenc e bet·ween any t wo values was tte true value of th e lost heacl in the se ct ion between the two. Th e tot a l of the lo st heads be t ween th e successive sections+ the velocity head in . the di scr.ar g·e must eq u&l H, the total he&,d. Due to the apparent irregularity of the re s ults, only a rou~h comparison was made to formulae for head lost at entrance, by bends and by pipe fricti on . Connno:r. f orruulae Jor . th 0 s e Ee:ad. lest at entrance = .5 V ar E.: - 2 2g Head lost by bends = v2 c det. by exp. and varying , 2g with the ra.tio-- diam of C - pi~e to radius of bend--&nd ~ ith the angle of the bend. 28 He ad lost by friction = f 1 v2 d 2g = f 1 9 v~ 4r 2g where r radius. = hydra.ulic The constant "c" or the efficienc:\ cxrressed as a decimal can be founcl as follovr"s Qtheoretical -- A 1 g·H 19 ~ ' ' where A = area of throat or smallest section. O.ac t,ll-a~.1 ~ - - - c = Qactnal A Y2gH Qth e or et ica1 Besides the readings with the tubes 811 closed, the readin g s of Q, H.W., ~nd T.W. were t aken once with tube ( 4) open to show tbe d.ecrease in effici enc;y due to an air leak n ear the throat oi the siphon. 4. Conclusions. Short 1~- aft er the tests were started, it was found that it was ga ins to be impossible to make more that a few tests _on one or two shapes of tt e mod el in the time available. Therefor, knowine that tte determinations of the rel a tive heE,.d losses in poftitions of" the sir;ron require d a nu~be r of dif f erent testf shapes for comparison to obt r in definite results, it was decided to spend mos t of the time on the re l at ions reg~ rdin g primin e cond itions. The ~e were therefor worked cut carefully as i nspe ction of the Cu:cve Sheet:::: vli J. l 2how. As statcc1 cefore, notr.ing c1efini te was 1mown about the priming relations. Therefor, as the data were ob- tained and. plotted. as outJined in "l,~e thocl of Test ior Objects 1 and 2", results were obtained which were both interesting e.r:d surprising. The first curves ottEinec1 were shov,n on Curve Sheet 1. The curves on Curve Sheets 1 and la are really the lines dividing the region of possible conditions into prime and probable no prime areas. For any point bE: lo 1N the curve tbe ch&n0es are 0 that no prime will result for that condition no matter how long it is main tained. For the conditions fif. shovm by any point above tte curve a prime will resuJt--the g reater the distance above the shorter the interval before a prime starts. A~ indicated by the points near the curve, there h , a aoubtful region elose to the curve wh ere sometimes there is a pri IT e ~nd sometimes not, rrhe most surprising: fee.ture on Curve Sheet 1 is the close aprroach of the one hole open curve toe, straight lin~ parallel to the tase. The ord inary theorJ oi the rriminf of a siphon ha s been that cf gr ad ua lly exhausting some a ir under the dischar ge lip-- a rise in headwater inside, etc. With one bole oren ttsre can only b e a ver;;' slizht :prNJsure below e.trncs:pheric ir,sj_d.t:: the siphon. Indeed, wi~cr: the wate1· risinc in the tr.roat, it looks ae th e: u5h tter E: v.;oulo. always 1:. e a slight comrression inside. jm-: t This is true of course up to a certain ti me, wh en or where it is not 1rnovm, but at s o:rne time, at a very deiini te height as shown bJ1 the curves, this must be chang ed to a slt g11t suction by the rush of water, and almost instant a neously the siphon starts. The secon c't surprising f eaturc was the e a se vvi th which the siphon primed with the discharge lip out of water .l', . 2' and Eo on as indicated b;/ the neg·&ti ve depths of' sub- merg ence of the dischar g e lip. This also seemed to b e con- trary to the air ejection theory since with few exce~tio~s ever~body believed that the discharge lip had to be submerg ed to produce a seal throg~t which air could be cjecteQ. These teets prove uonclusively th e t a seal is not neccss a rj on a s mall model, and coupled with this is t he fact that the full size siphon on the Ocoee River in Tennessee --see I late II-- does not require a seal. There might 1 e an objection to the ab ove statement because of tbe fact that the discharge end of the Ocoee 3 iver siphon as well 1_ s tl at of Mo del I were shaped so as to 0 j orm a more or less eifective seal with a srnBll an-,cuJ1t of water. The Model I I curves overcome this objection since it is seen tta t an even sn1aller d.eptt over tb roa t is re quire,d for a a isoha nrn lip like that st own on I'late III and on the photo e ra pl of the model. Just why a Emaller depth is re qui red on Lioclel I I is un cxf la in&b le--perhaps it is caus ed by a varyint speEd of rise in H. W. The iact iE that the few points availi.:.1,le show :.'.:.odel II curves lower with a ver: small 011 cnin c vvhE:reas when t'be disct&rce lip .... 1• <> . r::. I ,._, This seems fairly re- 31 asonable since i t seems that with s uch a slight cha nce of the falling water filling the horizontal section at the discharge lip, atmospheric pr0ssure would ex ist hiehe r up from tbe diochar?e th2,n with a longer curved discharge end. seen. The reason why a prime t akes ~lace is easily As the water rises there is no air cus~ion jar it to pu.sh 2-gain2t, as vvhe:n the di2 cbs.r3;e lip is sub merged. As soon as ½ater st~ r ts over the ttroat it starts a sort o::· plunger or friction action or oath to pusb some air out tt. e bot to rn . This undoubt edl;,· slightly reduces the pre ssur~ a t the throat, the water rises slightl~ and t h e fa miliar } recess b uilds up until the siphon i s frimed. The curves for the closed over throat condition are ma r~ truly r e pr8s ant ~tive of pr e sent siphon co~ditions tt-1:m the othe rs since i,n.~cticall;,· aL. of the siphons seal just before, just us, or slightly after the water starts over the thro ~t. CL'tl1 These curves show, better than words clescribe, t he relation between th e depth oi' [;ub me r- gence of the discharg·e lip and tne depth ove r tr.roat required. t o prime. The curve with all tubes c l osed si rn1: l :;· rE:, presents t:J. ver -;y- extreme case--i.e. where th e air vent is co v e1 e d long be :fore the v;a t er starts over tl1e thraa t. The variation ot both from the curve of one tuce open is much g1e ~ter th an would be expectei, c sfeciall~ since this closed ove1 throat condition has been so u.niverse,ll;y e.d opt Ed. The ex~nati on for tr e er e e t de_pth over throat required i s th at as soon as t he water starts to trickle '7, ') t... / .. ..., over the throat everythi~g is sealed and any further rise inside tl1e siphon '.'Deans compr c sEi cn. The su0cess of rrirn- in f;' depends upon a lar1:e enough stream iallin[' ttrough to entrain air and eject it under the disch a r r e lip. Also, the deeper the subThe rgeLcc of discharte lip the larger th ~t the de~per ttG £t~~ergen ce of the dibuhar r e lip the cli::::tance wh iCri tbif: entj ah:er.. air must t e ccl.r:.dc6 1:or·izontally has also an effect on tte depth re~ui re d is Ee(;n by the :fact tb2t t'ne curves of iv:odt::;l II &re uni:forcJ.~- lo- v,er to the ri ;_;'h t oJ the O line th 2.n those oi :·~odel I. The additional curve on Curve Sheet la wae taken with a small air va lve. It was though t thc.t perbcps better prir;; ing condi ti ::m s rnit(J-:.t be obt a ined with an air valve ~hich would permit the escape of air from the siphon and close as soon as suet ion bee;an. This v;as desirable principally because of the fact that the curve with one hole open would be the ~ost satisfuctory for s'La:r·ting whereas as sbown b;y Data Sheet 16 it would 1:,e the least dEsir~ble for efficiency. This air valve ~as supposed to g-i ve the ad.vantages of both. 'Fhe curve is above thE one hole open due &l~ost entirely to the fact that the small surface tension in the water seuling the rubber :flap vms enough to cause a slight co m1:,rt8sion ineide of the siphon. Tho idea is worth tr~int on a large siphon if i t will give even ae good results as in this Z3 test. The one objection to its presence would b e that it might freeze er get out of order and that it would be a working part to a piece of construction which owes sorne of its success to the leek of moving parts. A better method , one ¼hich afpear s to have teen used to a sli01t e~tent by ; recotti i n Italy (see Plate I, fi g . 2 and 3 2nd Plate II, top dra wing) is to have the inlet Jip (ai:r o:c wa.tt::r) 1·aised al;OVE- tr,e elevation of tte throat so th~t .l' of water is flowing over the throat before a Ee nl YESultb . It is believeJ ~het thiu will ~ive better starting conditions. ~be curves on Curve Sheets 2 end 3 art:; se lf explanator;y after the al,cvc rl iscussion. both sets of uurves instantaneous pr i me wh ere the disct&r J 8 lip is jus t a shor t cl i::tar.ce acov c or telc•v: rr. r· suriE.ce. stov,; tte lower va.1u es or, '. :lc d. sl I I . Tr'. iS is most 1:! .arkecl l . • ·. ; • on Curve 2hcE.t :::a . 'l'wo ~econd s i s tr. e ,t,imirnum tirn e stovm , tl·. is lJ ei r; g r;-racti ca11: t1: e t:i 11, c v.11ic h it to ok tte vmve of water to pass ttro ugh tLe sii,hor. . rcr..e suqlrh:ing point is that the si f t ( n pri~ce in all cases i n etorter ti me c;.n c1 at lo ; er depths o:f water ever t1 ie tnro a. t v:hcn the disct ~ r r c lip is l.rne;ove1·ed t1:ur, v:ben it is covered a. Eirdl - ar distance . TherEfor, this le~ves no roo~ ior doubt tr.at a pri ~e results better ana ~ui cker wittout a s ea l. This e~ems contrary to wtat ~oul d te expected , and O6l y autu&l 34 te~ts 1,,ill show whether this fact is e qually true with large mo dels. Just an indic a tion that thiE mi ght ne t hold good is ~he fact th a t with ~odel II the action at tte start occasionally went by jerks for 2 or Z seconds betore a full unt,roken dische.rt~ e rt'. sulted wben the disch 8rfe lip was .2' to .3' ~bove th~ T.W. It is believed that this r esult ed fro:-.o air :finJ.ir.[. its v,a;,· und.cc the dischar ge lip due to the siphon not flowing full. This reduced the suction and caused th e coluffin to pBrtly break and then start 2.2~ain. ''.' ith l,io del I ttis did not tak e p lace. This action gave reason to susrect that the siphon actjon would break sooner on ::.: ad.el II than upon #I v:t en tr:e discharg e lip was ur.covered. It vms :found that this , a.snot so--tte siphon uction usua11:; broke ~hor-tJ.;y before it started sucking a ir a t the inlet. tcHl: models. ~his ~oint was the s ame for- ".'hen the Liilwater filled up to a1,out .05' fro ~ the discharf e lip, the siphon a ction ~us then ver~ d ifficult to stor arnl it usue.ll;y continued until tLe inlet was tmco'tlen.:d ( even wi t11 several tu1Jes oren and suckine; air). Fr-o m tri s irreg ularit;y i rt action cour led with the fact that the siphonic aution occasionall~ brok~ without sucking air at the inlet, it may b e saielJ s aid th a t it is do ubtful whether a full size siphon would give satisfa ction if the disctarge lip ~ere n ot sealed. Z5 Data Sheets 14, 15, 16, and 17 show the results of the lost head and efficiency tests. As was stated above, these lost head r·esults, due to therE being only two ffiOd.eJ.s, would rave little corq)a!.·ntive vslur. '.:he fact is, in the tests ma~e the total efficiency was exactl~ the same with ~odels I and II. This seems to show that the shape of the u~per discharge lip has little or no effect on the Gffic1enc'i. a-csocn. Tests of other 2hapes are of co1nse needed. to verify this. AS to the lost heads in f Ortions oi the siphon, it will be seen that Lhe rEsults for any one test are rather irregular, although taken us a whole the four tests are vers 0ons•istent. It will lH:: noted. that testf· 14 and 15 give approxir.Gately .4' 102t head up to tbe iiret t1.ibe, while in 16 and 17 the averaze is .06'. Sin0e tbe iric- tion loss in this large area, short section is negligible, it ii.:' seen tr;at bl1 averafe would ind.L:ate thc1°t the ula iOrL'."i- 2 for loss at ent~cance, head.~ ( . 5<,v ._,g ) holds good . ._, r) •5 V 2g = .16' The fact is however, that the velocit~ of approach to the siphon has been neglected and this would indicHte that the loss is greater than indicated 1y the formula. <) For friction lost he~d the formula 11 v~ 4r 2g ~as used where "l" was tbe length bet'iieen sections in feet, "r 11 tbE: hydraulic radius (apIJroximately) in feet, and "i 11 , ~ .021, the constant for clean iron pipES of approximetely the area of the siphon cross-sections. (Value of 11 f" taken from table in Russell's Hydraulic~~able, page 189) This value should represent the friction loss fairl~ well anfl since it is greater than the measured loss on the lower he.lf of the siphon and much less tb&n that on the na1·row upper 2cction, it is believed tbat the com:;tunt is too small i'o:r- lonf, rec:tenr;;uler sections. ~here v,;cas _probabl;y- some loss clue to curvature, but d. ue to long radius, it V;·e.s not c;,,,nsidc,:red , s an ,ounting to much. There vrns un- doubtedl~ quite a bit oi edd;/ loss in this narrow section since there was usub.11~/ sor:e air go inc: tr1rough wi tb. tte v:ater ana this vwulcl. tend to drag tbe u1)p0r part of tte section. The bi~ lost head came between sections 4 and 5 and by looking- at ?late IV it will bG sec.o thb-t this section contained the joint in the siphon tesides being the smallest section as indicated b~ the a~ea. This 1eadily explains the bif loss. Just why all tests show the values for the swn, ? v2 +~ Z greater on the la.st three or four sections than w 2g on those directlJ above may be explained partl~ by the fact that inverted water c~lumns or "U 11 !T:e:rcury tubes were ~ " used in the U:!;!,er-bigh suction-tubes while umns WE re used. in the J oy,er tulles. would help cause tti~ difference js 11 u 11 water col- Anotter tting wtich the iact that during the teet the sections ~hict were under less than atmospheric pressure would be sligbtl;y smalle1 and thoBe above atmospheric (with int crnal rre ss ure) would. be s lightl;y 37 lare-er than tr.to actual measu:re6_ sections. These facts, coupled ,- ·i th the fact tnet tte intermittent sucking oi air ~t the inlet caus~d e yreat vibration in some of the water columns, all indj_cate that the results are as g ood as could be expected. The conclusions are therfor that the loss at entrance is a pp roxir!latel;y- what is indicDted lJ;y the standard· formula, th at the larg est part of the he ad lost is in the small center s e ction, and tbat there is veTy little h c&.d lost in the di verginc d owns1;out. The total efficiency show~ no 0 OL the ~ ata SheetE is of :reat value except as a compe.rison between the models, which bas already been mentioned. 'l'hat the £:fficiency is l0OJ~ in one ca.se does not indice,te anything wrong ·,-.i th the res ults but sho ws that such an expressi on fo! efficiency is plainlJ' of no value wh8r e the c ross-sect ion i c not constant or nea~ l;y' so. 1J.·his value could run u:p 1m;ch over l00'j'o due to the Venturi action, \':tich gives a discharge through the small section greater than the a0tm.il ciiiierence in heaa wo uld call for. The figures a t the bottom of Data Sheet 16 sho w how the efticicncy is cut do~n by an aii leak, in this case a 3/8" hole. As a whale, th~ results of ttis thesis hav( been satisfactory. The results have been interpreted in the light of rihat in f ormation was av a ilable. '.rhere Hre man;y points 38 about which suggest ions might be made as to future tests or as to future designs. Eowever, due to the fact that everything must be interpret ed in the light of the rer:fo rmance of full-size models, and as more in±onnation is becoming available from time to time, the writer believes in that" an;y future tests to be made, a comparison o:f this thesis and the actual p8rtot<mancE. of constructed siphons might give a clue to even more valuable tests and data. In closing, the writer wishes to state that he owes man;y thanks to .:r. Louis C. Hill of Los .Angeles and to Professors Ford and Thomas of Throop College for the many valuable drawings and suggestions which have helped to make this thesis very inter es tin g work, so much so in fact, that it require d more th an double the given amount of thesis time. U~-i J l ~ ~ 1,e /9/G. DATA SHEET 1 .... See Plate III for section of these siphons. Obtained. from IJr. Louis C. Hill, Consulting Engineer of Los Angeles, California. The Report of Observations by E.V.Baron, Aug. 21st 1912 on the Siphon Spillways of the Yuma Project of the Untied States Recl~mation Service. Date Siphons Ho. Jul.24 4,5 24 4,5 25 3,4,5 25 3,4 26 3,5 26 3,4,5 29 All 29 1,2,4,5 29 · All Aug. 5 3 7 1,2 7 1,2 8 2,3 8 2 19 1,2 19 2 Theo velo Theo disc Meas a.isc Coef±. 11.61 2'7.3 11.80 2'7.5 11.'77 27.4 11.90 27.7 11.85 27.6 11.60 27.3 10.65 . 26 .2 11.00 26,6 10.87 26.4 11.90 27.7 11.60 27.3 11.60 27.3 11.48 27.2 11.87 27.6 10.98 26.7 11.82 27.6 620 625 933 630 627 930 1488 1205 1498 315 620 620 617 314 606 314 484.9 479. 6 693.5 443.3 505.1 663.0 1043.4 853.1 1012.7 243.3 405.0 415.0 419.3 208.0 432.5 202.0 78.3 77.0 74.3 70.2 80.5 71.5 70.4 71,0 68.0 77.5 65.5 67.1 68.0 66.5 71.5 64 .4 Head Observed depth of water over Lip to start sipbon. Tube Ho. Outlet Submerged 5.35 feet Outlet Submerged 6 feet 1 2 0.40 0.35 0.15 0.25 0.40 0.55 3 4 5 0.45 0.25 0.45 0.50 After a number of leaks were c Jo sea. up in tubes 1 and 2 they primed at c1epths a·bout O.10 less th a t tbe a bovE-. Seal broke i:n a few minutes when water surface had dropped about 0.1 foot below air valve. DATA SrlE1: '.l.' 2 •• Characteristics of the model. Table showing area of siphon cross-sections at, center line distances betvrnen, and gage reaclings for, tte tubes attached to the siphon. See Plate V for drawing. C .L. dist betw sec. • ins Up. lip Inlet . Tube 1 2 Th" Th" Th" 3 3 3 C .L. Desgn Actual Measurements dist Area Lve Ave l,.ve . Ave b etw SQ dep width area area sec. in ins. ins. sqin sqft ft. Z or read elev. feet re ftfr. to , 1. tube 10 Gag e 0.82 6.18 0 0 08. 9.0 12.2 10. 3.25 .271 64. 5.5 12.18 67.0 8.0 .667 30.12 2.67 .12.25 32.7 7.9 .658 30.0 2.71 12.15 32.9 .765 .465 .227 0.97 6.03 0.37 6.63 top---.oo .229Cen,J0 6.87 ottorn--.22 .658 30.12 2.63 11.80 31.0 .2155 0. 3 7 6.63 4 7.9 .658 30.25 2.55 11.16 28.4 .1975 0.97 6.03 5 , 7.9 .183 33.95 Z.27 10.21 33.4 .232 2.15 4.85 6 14.2 .254 3.63 3.37 7 11:s 1.48 3 8 .58 3.9o 9.37 36.5 8 15.5 1.29 42.61 4.83 8.65 41.8 .290 4.93 2.07 g 10.3 .858 45.30 5.80 7.88 45.7 .318 5.78 1.22 lQ 14.2 1.183 49.0 6.91 7.24 50.1 .34 8 7.00 0 Modlll 10.7 . 892 56.0 8.12 7.12 57.8 .401 7.55 -.55 4.0 .33 56.0 57.8 .401 Model I only Disc Disc. Lip, Model I see photo or desc. page 21. 7.14 11 11 11 11 11 II 11 21 7.08 " ', t...l •••• Model I. Grad ually increasing depth of water over thr oat. '.I'ube (4) open. :dge of throat ga ~e read ing . 22 .:Cischa.rf::,'G lip " " 7.14 .J ottom or Top or 1 • ,i • IJ. . V·/ . Dep th eve r Jisc . lip ft. it. ft. f '! ~ .H 6 .Z 5. f37 6 .5 6.0 G. 6 5.7 5 .7 5.8 5 .7 6 . £6 6 . 53 6 .1 G.6 . r,,:_ 6 ...., 6. 9 5 . 85 5.6 5 .65 5.45 5 . 65 6 .5 6.65 '7 . 25 . 84 .10 . 095 . 0 95 . 0 95 . 088 .11 . 045 .07 . 08 . 06 . 0 65 . 095 . 09 . 07 1.27 .6 4 1.14 1.54 1.4 ~ 1. 44 op en .2 0 1 7f. 1.4 4 open . 20 .1 8 .61 1.04 . OS open . 20 . 095 .11 .54 . 84 open .30 .24 1.29 1.54 1.49 1.6 9 . OG .11 .14 .1 0 .13 . 07 .oe • t.,, . .. .1 2 .1 2 5 .1 25 .125 .1:2 .11 .175 .15 .14 .16 i::; ,• 1 VD .1 25 .1 3 .15 1 ._,'7. .125 .11 .14 .11 .cc .. 1099 .4 9 o,r;en .11 • 1 2!:i 1.49 .64 .11 . C95 . 0~5 op en .1 0 ?.T o _prime Slow Pr i me !'.i o _p ri me Quick 1ir i me .i:I o pr i me . .15 .14 .1 2 .11 .1 2£: .10 :?c emarks ? e qd. :D epth ov er Ib r. to prime Ho prhne Slow prime prime Ho rrime ?o }:fo prime no :prL.': e DATA 3HE=T 4 .... ~ odEl I. 8rrduaJJy increasing depth of ~ater over throat. Tube (4) open--closed as soon as water starts over throat-- e age rE:ading .22 Discharge lip " - 7.14 Bottom or Top or E.9 .10 .12 -. 05 -.17 -. 05 -. 06 -. 09 -.13 6.88 6 .4 5 .7 6 . 85 6 .z,5 5.6 6.75 G.15 . 6 (I., 6 .4 6.1 6.8 G.65 6.9 .10 -.10 -.14 .OS . 08 -.115 -.14 - • H3 - . 1:. -.105 -. 055 .10 .095 . 085 • O'J 5 6 . S3 . Ov5 -.20 -.2 0 . 005 -.01 - .2 0 -.11 6.1 7.4 7.6 6.8 .0 9 .09 -.13 6.8 - . lJ 6.2 6.05 '7.02 '7.0 6 . 04 6 . t18 7.04 7.0 7.28 7.6 7.0 G. 8 6,8 .08 -.115 OL-. 02 . 085 . • O'J -. 005 -.11 5 - , 086 Depth over Regd depth Remarks Disc . lip-ft over Thr. to Pr irr:e 1.24 U o l ir irne open .10 .1 0 .27 SJow prir.iE: •26 .7 4 .27 Jueg.at-.04,no fl' ■ 1. 44 . 29 .28 • 7 <J .31 JU8'[ ■ at-.02 1.54 .35 Jugg . at .05,no pr . . 05 .1 2 Quick prime .39 • <-'~ l;t_ (: .9~ .36 open . 05 open .10 .24 .74 1. 04 . 34 .1 4 .14 Jug·g ~at-. 03 . 335 .3 6 . 40 .35 Jugg.at-.08 " " :i ,no pr. Water ris. fast • 2 <J • 24 open .10 open • 20 Ofen . 30 open .]5 open .20 . 94 1. 09 .12 . 14 1.10 OJ:l €TI l. 84 • 26 open .46 . 34 " .275 .1 2 .125 .1~~5 .1 25 .1 25 .42 Juer-at-.06,nc pr . .42 :To prime . 215 •42 . 4 15 Exp.air -.17,no pr. H. i7 . r is. i' as t Jucjg.at-.10 .i:To prime no prime .65 • 24 open . 21 .26 .10 .14 oren .14 open • L~6 .14 .14 . 335 .1 8 .J+ .Joo Air out -.10 Slow y;rie.e • 2L; .1 35 , r, • ..LU 31 ow }ff irne DAT.A SHE:ST .... I-:Iodel I. 5 3r aduall ~ increasing depth of water ov er thr oat . AlJ. tute::: closed. Edge of thr oa t ga~:e re1:ding . 22 II 7.14 Jischarge Jip " P.o tto rn or Top or r_r • '._'i • lI. "',.1J • 6.9 6 .5 ,. . 0 .... -. 21 G '7 -. 20 6. 9 6 . 35 -.11 -. 20 6.9 6.4 C. 95 6 .5 -.1 0 -. 21 -. 06 -. 21 5.65 6 .7 5 -.1 95 -.1 S5 G. 90 6 . 92 -. 095 7 . 08 '7.02 . 08 . 02 6 . ~8 - . l)3 ■ u - A -.1 0 Rcqd depth Remarks . Depth over over Thr. to J isc.J.i p-ft. ::?rime . 24 . 25 . 4. 3 . 64 :~ 0 pri me • G4 . 42 D'Ta ter over th .. 02 Ho pr i me . . 24 . 33 ;;:-a t er over th .. 04 70 . 42 '.Va ter OVE:r th .. 08 no prime . 24 . 32 ,ga tcr over th . . CE . 74 . 4:3 No _prime ,-, 1 .1 9 • 20 :1!ater over tb .. 05 . 64 . 43 "!ate r over th .. 05 No prim e , 4 15 Jugg .at-.10 ,n o pr . 1. 49 r, () • Q.:, . 4 l fJ .Air out -.1 2 S l ov: pri me 1 ;;?ITl l n . . 24 . 310 Air out - . 0 7 .zo ~·:at er over th .. 06 2" Ai r out - .10 . 06 .14 '. ·•a t E: r over th .. 14 . 20 -r'.r ater over tb .. 06 .12 .Air out at .1 6 .1 6 . 25 ":'at e:r ov·er th .. 07 5 Air out at . C2 . ~ 1 . • ~ 1 L~TA '.i.1 ube ( 4) SHE~T 6 .. llode l I. opened with a certain depth over thro at . Edgo of throat ga ge r eading .2 2 11 " 7 .14 .Dischar g e lip 3 ottom Top reacl. read. in prim. ft sec. ft 5.8 5 .7 5.0 6.3 6 . 25 5.70 6.1 6 .15 5 . 65 6.4 6.2 6.4 6.4 6 . 05 6.93 6.52 6.15 5.74 7.0 6 .6 G.14 5.7 6 . 04 6.52 6. 88 6 .42 6.7 6 .25 5.65 6 .75 6.3 5.8 6.0 6.8 6.4 6.0 5.58 6.6 6.24 6. 2 5.8 6.56 6.12 5.78 5.52 .085 . 05 .09 -.20 -.2 0 .06 .07 -.2 0 .0 3 -.21 .06 -.21 .o~ . ul .11 .07 .02 -.04 .045 -.06 -.11 -.11 -. 01 -.09 .12 -.045 - .14 -.oz -.05 -.195 -.12 -.125 -.15 -.20 .0 25 .01 -.03 -.01 . 055 .11 Time 12 1.24 1.44 .1Z5 .17 .13 6 .84 . 89 1.44 1.04 .99 l.4S .74 12 • 'J4 6 .74 .7 4 1. 09 .21 . 62 .99 1.40 .14 13 12 7.5 11 10 11 25 13 12 10 10 6 8 7 8 20 8 7 8 8 7 6-7 7 6-7 7 8- <J 1.00 1.44 .20 . 62 open .10 .26 .7 2 8-'j 0 0.; 20 25 15 8 No prime .42 .16 .15 .42 .19 . 43 .16 .43 .18 . 21 .11 .15 .20 .26 .17 5 .28 .. Z3 r;._r,. ...,..,, 1 .2 3 .31 .10 . 265 . 36 r· .27 .415 .24 .345 • 7 4. Ho :prim£ . 42 .89 1.49 .39 .84 1. 34 1.14 . 34 1.14 1.56 .5 4 .90 . S4 1.Z4 .58 1.02 1. 36 1.62 -. 015 -. 0 2 feet •2D 9 Rem1:.'!. rk s Throat .44 8-9 10 12 10 .07 Depth over 1.34 6 6 . 03 .. 08 :::::ie pth over Dis er:. lip. feet . 37 .42 .19 5 . 21 .25 .23 .1 65 .11 .19 .14 .15 ~o prime 50sec Table 6 (cont) .. :.~odel I. Bottom read. ft Top reacl. ft 5.58 5.55 5.50 3.55 5.45 6.7 G.5 5.65 5. <J 6.0 5.6 G.82 6.44 7.24 6.94 G.80 7.42 7.02 6.64 6.55 7.5 7.45 7.30 7.24 6.86 7.4 7.25 6.86 7.08 7.62 7.45 7 .45 7.04 7.24 .08 .05 .07 .08 .07 .045 .10 -.18 -.20 -.21 -.20 .05 .11 .10 .11 .06 .065 .11 .08 .11 .09 .09 .'055 -.01 .07 .12 -.10 .065 .11 .09 -.065 -.03 .12 7.14 7.13 6.46 7.6 7.4 7.0 G.64 7.40 .135 .11 .08 .06 .04 .105 .06 .04 .oo Deptb over Disch. lip feet Time in prim sec. 1.56 i:;c 1 ._,,:) 1.64 l.5<J 1.69 1.44 .64 1.49 1.24. 1.14 1.54 .26 .70 open .10 .20 • 34open .28 .--, • 1G .50 (' • 5 ;1 open .36 open .31 open .16 open .10 .26 open .26 open .11 .26 .06 open .48 open .31 open .31 .10 open .10 . 15 18 20 20 11 7 6-7 6 7 11 8 11 2.5 9 15 5 7 7 35 6 9 2 6 12 .oo 12 .01 15 .69 5 open .4 6 4.5 open .26 .14 16 1 '7 .48 4 open .26 • t.., .Cspth over Throat i'eet .14 .17 .15 .14 .15 .175 .12 .40 .42 .43 .42 .17 .11 .12 .11 .16 .22 .165 .11 .14 .11,, • 1 ,D .13 .165 .2 .., :?emarks No prime 25Eec Ho prime no prime . No prime 1-21 rnin No prime No l)r ime No prime No prime '7 .15 .10 .32 .155 .11 Fo prime .13 I:To prime .285 .25 .10 ?rime almost broke at start .085 Ho prim8 30sec .11 .14 .16 .18 .115 .16 .18 Tube ( 4) cl c s Gd as s oon al w·at e r starts over throat. Inlet unc overed and ti me to prim e taken for various dEp t hs over ttrcat ana various tailwa ter el evatioDs . :So ttom reaa_. it 6 .5 6.4 2 5.9 5.75 6.65 6 . 05 6.6 5.95 Top rea c1 . f't Time in prim sec -.145 -.155 -.1 8 -.0 85 -.185 -.16 -. 20 16 .oo 6.6 -.lS 6.0 6 .55 6.04 5.95 6.65 6 .5G 6. J5 6 .7 6.7 -.20 -. 08 5 -.16 -.2 0 -.075 -. 0 75 5.70 7.;3 5 7.25 7 .7 7. 24: 7.55 7.5 7.2 4 6 . 8a 7. 26 -.1 95 -.20 -.065 -.20 .10 . 08 . 05 . 08 .O Z5 .00 5 • '70 LI 20 30 12 17 8 17 22 Depth over Di sc. li p f'ee t • 64 .72 1.22 1.39 6 6 5 4 4 4 8 5.5 . 54 1.1si .54 1.14 .59 1.19 .49 .59 1.0 9 . 44 .4 4 1.44 open . 21 open .11 open . 56 open .10 open . 4 1 open . :.:=<6 open .1 0 -.1 8 . 06 . 08 -. 0 5 -.0 8 - .l~ . 04 -. 20 25 .14-5 10 .145 -. 0 7 18 .oo.'"\ 2 open .31 C. CJ6 .11 r;1., ;.:, .__, v . 08 7.2 4 7.30 6 . 84 ',i . 0 4 6 .6 2 6.90 6 .9 0 6 .8 0 7. 06 -. 08 2 open .10 01Jen .16 -.1 25 . 02 -. 06 -.1 0 -.1 8 -.11 -. 0 1 11 7.14 7.24 6 .92 7. 40 7. 24. 7.3 8 7.14 7 .14 7.4 5 .os 6 2 2 2 s zo . 30 open .12 .o o o,pen .1 8 .1 2 open . ~o open .1 0 op en . 24 • OV .4 0 No prime l rr in J? o prime 11- " .405 • 3 t3 .42 .40 .4 2 Not cl. ti lo v .tt. .305 .3E No pr ime 4 0seu .42 .10 .52 .22 lZ .24 .2 4 . 08 No prime .2 95 .2 ~5 .415 .285 !T o p rime lrnin .12 .14 .17 !:o i:ri me . 14. .18 5 . 2 15 .1 9 . 40 .16 .14 .27 .2 0 .36 .1 8 • 4: 2 . 0 75 . 0 75 .11 .30 .13 . 345 11 4 .365 .37 .30 5 1. og 1.10 18 25 40 9 20 Depth over Remarks. Ttroat fe et . 22 ~r o p ri me . 20 .2 8 . 32 .4 0 ~1 o p1·ime " + I\ ( CODu Data '2te et 7 Bottom read. ft 6.96 7.00 7.14 7.7 7.24 7.7 7.2 7.4 7.65 '7 • 6 7.4 7. z. 7.09 7.04 7.02 7.00 7.155 7.19 ,,. '.!.,op reaa_. ft -.025 -.12 .10 .. :.Iodc 1 I. Time in prim sec 10 5 r r- 2 .D 2 -.06 .12 . 06 .11 .09 .09 .OP5 l ._.,,;, .08 .()6 2 C, ;;, 5.5 JO . Dcptt over Throat feet .245 Disc lip i'eet . 18 .14 0 .oo .oo open open open open open open open open r, ,:_, .56 .10 .56 .06 .26 .51 .46 .26 open .16 .05 .10 10.5 .14 r;· ._., ,,, r::'ube ( 4) open. ,,. .14 open .015 o;)en .05 ,-?· .22 .28 .10 .16 .11 prime ..1~l 1:0 }Jrirne ro prime .135 ..14O Jugg.at.165 no 1-r ?o prir,e m T'!"" fop or T I T~ I l • ·:•: • 1~. '•'J • f'eet. 5.86 6 .4 G 6.5 5.55 5.66 G.65 :feet. .095 .12 .11 .11 .11 .12 .10 .12 .09 .105 .12 .125 .125 .115 .12 .105 0 (,.., .12 .12 .115 6 0 ~H; ~V 6.98 7.38 7.25 7 .14 6.80 7.06 5.9 6.84 b.64 5.60 G.46 6.10 6.0 7.~5 7.2c3 7.40 110 r,· ._,, c.,; .16 lp .08 O V Ifo prime No prime ,.. "r-, ,,. no _prime ,;, • " \ ,.J .,, :d1e of throat gage reading 11 Eottorn or Depth over Discb lip 1.22 . 6 r, ,:_, hP • v ,_ 1.48 1.42 . 4z. • r;, [-~ _,, 'L,I . .10 open .30 open .16 open .06 .28 .02 1.18 .24 1.44 l.4C . C: 8 .90 1.08 open.Z7 .11 .08 open.Z0 open. z,2 ' r- r. oOG ?en;arks ..• 542l 2 .oo .12 .-04 . ,l. :DE:r,tt over ti .22 '7.08 remarks ~eqd dep. over throat to prime .125 . 10 no 1)rime .11 .11 r o frime .11 I':o rrime • lCJ I:o 1-, rime .12 .10 . 12, .115 .10 .095 • Slow prime ;; u Oorc .105 .10 .115 .13 .10 .10 .105 .14 F e prir.'.le .l 1 ~To prime .14 11~ 1.,: 0 ITo prime :'To prime rrirne 1:o prime ~-~ 0 :prime DATA SHEE~ 9 .. ~od eJ I I . J rad ua ll~ i~ c~ eas jnf d€p tt of wat er over throat. 'l'ute ( 4 ) ort,n ur,.til Ymtcr s t ,1. rts over -t r root ano. tten. cl~'. SE ,l . ~~dee of t h ro at ;_::a2·e r t: ad i r:;,i_: . 22 II 11 7. J 8 J i sc rF.rCE: I.if :Oo tto rn or ft 6 . 54 ft -. Jl 6 . 52 7 . 25 - . 07 . 1J 5 6 . 26 -. 135 Depth over Disc lip . ft 5 ,:j.5 6 0 1, cn .1 7 . 82 -.1 6 1.Z3 - . 12· • m -·, l. • ~I • 5 . 75 6 . 25 7.1 8 6 . 84 6 . 20 5 . 94 'I.'o t> or . ,,, 11 • i ' • 8 v,:;, - . 125 -.1 8 open . 10 . 24 .7 8 1.18 5 . S5 -.1 5 1. 13 6. 8 -. 08 -.1 4 .2 8 6 .16 6 . 92 7 . 20 6.5 6 . 94 7.1 7. 0 7 . 08 G. 88 7 .15 7 . 08 6 . 65 G. 75 7 . 30 6 . 80 7 . 22 6 . 88 7 . 20 7. 7 6 . 42 6 . 05 .1 2 . -. 06 . 92 .oo .1 6 .11 -. 065 . 005 .1 3 . 05 '7 • 1 i.J -. 04 open . 12 . 58 .14 oren . 02 . 08 .J O . 12 -. 095 -. 09 • Oc'J .oo 01j en . 20 . 07 .oo . open . 43 r;z, ,-.z, '-' '-' • 9'' _r.:; . 01 .105 . 05 .:. . 0 75 . 2G open . 24 . 20 open . 12 o_pcn .62 .66 - .1 6 J . 03 -. 08 5 . 06 Re q der over thr to Fr i me: ft . ?: c: mar lrn r; · ~;· Some air out - .02 .2 9 H. -__, . rii:~ slow "-. 0 1 . 115 .Z55 Ai r - . 0 7 , j ug·e-- . - . 12 ~'To prime . 38 Some a ir out -. 05 . 35 . 10 Som e a it out . 04 . 28 .34 5 " -. 04 " . 40 Ai r -.1 0 ,jugg .-l J No p rime . 3 7 Ai r - . 09, jugg .-. 12 i! o prime Some air out-. 02 . 30 .3 6 Air -. OG , j u gg .-. 12 . 22 . 11 . 285 Some a ir out-. 01 . 215 . 09 .1 7 . 09 Some a ir out O .....r·-,. . 26 .1 2 . 10 ~ , h • c...,,J... SOILC air out .oc . 31 .1 3 Ho 1;rime . 305 .1 4 .l'"io J,rirn e . 21 . 115 . 17 . 295 Air -. C) J. , slov; ris . n.·x . r ,G. .(,; Air & j t:_f g . -. 11 • '--'' V . t,) . lU 0 .1-:•.:· -~ r. 1,_J.:._~ ....... .J-. Gradually incrcasine:: depth of w8ter over throat. All tube2 c loeed. Bottom or ,.- r:· .J. • . . ft . 'l'op or F ·,; .l. ... • . I :Jepth over :'..iisc liJ: i • 6.50 ft -.19 G.8 - • J..•) 6.U - ft .48 .28 .28 -, r, , ,, fi.65 7.04 G.~z 6.72 Ci. 65 7.0 6.S2 "' • Ed.g·c oi throat vage ru~ding· . 22 11 :!Ji scb&r[E Lip " 7. 08 J.t....i -.205 .10 -.02 -.15 -.16 Rcq dep over thr tcprime ft .41 Ov.th.06,air-.12,sl pr .25 Ov.tb.06,air-.08 .Z5 Ov.tb.08,air-.07 .425 1:0 prime .12 Cv.tb.05,~ir .05 ov.th.10,uir-.06 .04 .15 .Z8 ov.th.10,air-.06 . oz .19 Ov.th.10,air .10 .08 r; ·. f) • .. _,t..,, -.1 0 "' "' :,I- DATA Alr ?emarks 11 .. ~ode l Il SHEET valve attached to tube (4) yer □ ittinc the escape of air but closinc as soor~ as suctior: l:egan. J:ottorn or ..L • • : • "' it G.05 7.2~ G.06 5. e.o 7 .14 7.08 C.82 G.7D 6.25 6.12 5.45 7.11 G.40 ? .16 6 •vh 6.80 6.GO 6.20 S .60 6.96 6.58 7.08 6.70 7.04 Tor, or f~ . . it .085 .115 -. 0 1 . OS .11G . l~■ Ov,~ .04 .07 .08 .0 8 .125 .07 . 105 .05 .075 • 0135 .09 .055 .09 ..OGOl ... 'A • hh vv .12 :Depth over .Jis:J li:p it 1.03 o 1 en .16 1.02 C) <') l -~~ (:r: en . C:6 .oo .2G .30 .75 . ~; 6 1.63 01en .03 .60 or,en .08 .58 .20 .4G .88 .28 .12 .50 .oo . 2·8 .04 ~qJth over '.I'hroat it .1~ 5 .10b ,, r 1)cm&.rks 1 • 2:.t.J . 1 ... '7. .105 .09 .17 .1 8 .15 .14 .14 .09fi -, r:- • l. 1,..) .115 .17 .145 .135 .13 .165 -, , , • ..L c:::.· .16 0 (,., .165 .lC . I n lEt O.P. f •Y.l'/::;1.;: G 12 . . ~-.~ocle 1 I I Qirr.--r:-: m i,.,., _,_ _:_..1.. ..; .-:.i.L. ? e~di ngs taken wi tt in l et op ene d ~ith wa t er ovtr tt e th r oat as r eco r ded . Tub e ( 4) open a t a ll times . Zdge of tlu:0a t .J i s cha r ge lip gag e read i ng II Bo tt om r ead . it Top read . ft '.l' i me i n p ri m sec G. 68 6 .14 7 . 46 7 .1 6 6 . [i6 -. 025 - .095 - . H; . 10,,, 0 ._, . 07 -. 05 .11 5 7 6 2 12 7 ~-5 2 .1 05 . 11 . 06 . 08 .015 . 095 . 02 .07 00 .1 2 .1 0 . 02 . 1 ;:;5 . 08 • 1 0'7 . 065 12 6 . 48 7 . 58 7 .1 6 6 . 78 6 . 40 6 . Z-6 7 . 62 7 . 54 7 ,__,<;?4. 7 . 30 7 . 14 . G.7 G 6 . S4 6 . 51 7 . 36 7 . 20 7 . 16 G.94 6.8 6 . 54 6 . 24 6 . 60 7 . 02 6 . 84 7 . 28 ~-~ 5 . 86 5 . 74 (; . 94 6 . 50 . • • ;I ~~ 1 05 -.1 65 - .14 . 04 - . 1 s, . 02 .1 15 9 10 . 5 ~- 0 4 7 12 19 22,0 7 11 Dep t h over :Disc li p tee t . 40 . 94 op en . 38 c1ien •. 0 8 . 22 . GO open . 50 or)en . 08 . ~.o . 68 . 72 open . 54 open . 46 open . 26 c:r,en . 22 oren . 0 6 . 32 . 14 . 57 open 9>-< o_r:;en .1 2 op en . 08 • ,..., 1....- .14 . 28 7. 5 7.5 6 . 54 • 84- 5 4 . 06 . 28 b.5 3.b . 2~ open . 20 • Ol'J' r:) 20 - 2 5 1 1. 5 . 075 -.1 3 8 1.18 1 . 23 1. 24 .1 4 5. 5 . 58 .O . 22 7 . 08 ( c onti nued) Dep t h ove r Thro at feet . 245 Rema.rks . Zl 5 . 40 .12 . 19 .15 . 27 .1 0 5 '':'en t by j(:jrks un t i l water cov . discho. rg e lip . 1 15 .11 I~o p r ime 30sec .1 6 .14 :ro p rime . 205 . 1 2[) no pr i r1e . 20 '.7c n t by j lBrks .1 5 J e rks ' til l \,; U~" .1 3 . 10 . 12 . 20 . 08 5 lio pri me .14 t"'1C .I lJp pr i me 2bscc .1 55 . 21 5 . Zf3 5 . 36 .1 8 . 41 V • • \. j . 20 . 105 i!'o _p r ime .1 3 . 17 .145 . 25 1 40SE..C D£,te 2-h eet 12 (contir:.ued) ~,~od.el II . Bottom r ead . ft reed . 'Iime in p rim ft s ec Dep t h over Di sc.; li p f eet 6 . 04 5 . 98 • 0f3 . 07 5 . 94 ♦ 20 15 ?. 5 7 . ti 1. 04 1.10 1.14 6 . 24 . 60 1.10 5 . 58 6 . 84 6 . 48 5 . 9f.3 7 . 34 7 . 26 7.4 7 . 25 7. 21 ? . 06 6 .7 0 6 . 36 6 .1 2 b . 66 [:, . 50 7 . 32 7. 28 7 . 24 7 .1 2 6 . 65 ? . 40 ? . 3~ 7 . 26 '7 . 1 8 7 .11 6 . 8fi t;. 8 6 . 48 6 . 25 6 . 04 5. 9 5 . 64 C. 5 8 6.8 5 . 74 b. 6 b . 58 S.'op r_.::, i:-.:, () \...VU -. 03 -. 05 -. 16 -. 06 . 09 . 06 . 06 . 095 . 0 55 . 095 .10 -. 05 -. 20 .11 -. 06 . 095 . 08 . 055 .11 .12 . 06 . o4c . 06 .10 . 095 -. J75 . 05 .10 . 06 .1 0 5 7 7 6 6 9-10 17 7 5.5 7 5 G .op er. . S 2 b open . 26 6 15 6 6 7 20 op en .1 8 op en .10 open • Ot..J,;, 8 Q., ..., 8 .105 . 04 . 065 . 03 . 09 10 10 7 r;:, op en . 26 cp e n . 20 O.J! e L . 3 2 op en .17 op en . l ._,e;· . 02 .38 . 72 . g6 1. 42 1. 58 op en . 24 0 1) 8 11 . 20 op en .1 6 open . 04 4,;, .._, . 04 . O.._, l. G0 8 ( ccntirrn ed.) .18 . 20 . 60 .8 1. 04 1.18 1. 44 1. 50 1. 28 1. Z4 1. 48 1. 50 Dep t h ov er ~emarks Th roat :feet .14 .15 . 25 5 . 25 . 27 . 38 . 28 1 17, Ho pri cne .16 Pr i m. & went t ;;,., jcr If .1 6 " 0 ,• 1 "--0 :No p r. wat fal i st .165 .1 25 .12 . 27 . 42 . 1 1 :1o :pri r:~ e . 30 .1 25 :no pri me .14 lTo pri me • V .lE- 5 .11 .1 0 No _prime .1 6 J:To pr i me . 17 5 Je r ks n . 16 .1 2 .1 25 0 or:c: • hi .,J c. .l .17 1 ..,9 .16 .1 2 . 1Io _prime • 18 .11 5 ro i-:,r1.me .1 8 .1 55 lo . ~ . 1 ~; .1 9 I:! o pri :1,e c5sec De.ta Sheet 1 2 ( con t inuecl) ivlodel II . bot t om Top r ead. • reacL :ft ft 'l'i me i li rrim sec . 08 3 8 . OG 12 • Z-4 -. 04 -. 18 - .15 . 02 - . 10 ? .7 0 . 56 1 .1 8 open . 30 . 33 .7 8 . 30 r r:, 1 • .Jo . 02 .14 .1 6 .1 6 open · . 56 op en . 46 o:r,en . 06 op er. . 40 open . 26 open . 20 . 26 7.4 7 . 03 6 . 74 6 . 38 6.5 5 . SO 7. 38 6 .7 5 ~ r;z b • .., 6 .7 e 5 .7 2 7 . 06 6 . 94 6 . 92 6 . 92 7 . 64 7 . 54 7 .14 7 . 48 7 . 34 7 . 28 6 . 82 7. 6 7 . ;:,'± 7 .14 6 . 84 .oo • () 3 -.1 6 -. 1 7 -. 08 .oo . 02 . 06 0 4. 04 .11 . 035 . 06 . 03 - .14 . . 05 4.5 6 Z. 5 i:-:; • V ~• )· 8 4 6 +2 6 6.5 8 5- 6 5- 6 13 5 5 5 • () 0 .. 095 4 OL c.; . 10 15 -1 6 ~ Depth over Disc li p fee t open . Z2 . open . 2 6 0 lJE-Il ~ ...; • D (.' ":J f;') ::) '-- o~er: . 06 . 24 Dep t h ove::.· Throat feet :-;:em~nk s . 22 .1 4 .14 . 26 . 40 • 'Z:, 7 . 20 . Z2 1 ()., . 40 . 39 .30 . 22 . 20 .1 6 .1 8 .1 8 .11 .185 .1 4 l{o prim e . 1 9 Je r ks . 36 . 22 J(rks . 1 8 J (: rks " ,: : • l Cu J0 r ks ' til l .1 2 . C;OV • ~g1:r~rn v ... ~L-'--~ J. 'J ATA Tub e ( 4) closed 2S r,_ l ._,, . . :·.Tod el II . soon as wa ter starts over thr oat. Inlet uncovered t:md ti me to _prime t aken for 1/&rious d. epths over throat. Bottou1 reacl. ft. 7.1 8 7 .1 6 7.1 6 . 86 6 . 86 7.20 7. 24 · 6 .5 4 5 . 88 6.78 6. 3 6 7.14 6 . 85 6 . 44 6 . 0S 5.65 7.12 6 .84 G.54 G. 68 6 .1 8 6 . 04 6 .1 8 7 .1 6 6 . 86 6.4 6 . 04 6.20 5 . 80 7. Z2 7. 06 6 . 81 6 .50 6 .1 6 7. H 3 7.1 8 '7 .1 4 7 . 24 ? . 35 G. 2 1 7 . 24 ?. O 6 .6 <= 6 . 64 7.44 '.[O}:i read. ft . j _[! S::ime p rim sec .1 0 . 06 .1 0 7 G 8 - . 11 .0 8 .10 -.21 -.21 5 1 2 -13 25 10 11 12.5 12 2 .5 13 19 25 .oo -. og -.18 . 005 -. 045 -.11 - .145 -.205 .07 -.02 -.1 05 -.12 5 -.17 -. 06 -. 09 . 08 -.1 8 -.10 5 -.1 8 -.15 5 -.2 05 • '-' V 5 15 20 <;J -10 15 5 .5 0 \.., 5 2·0 18 20 l r, . Cl 2 .5 . 06 -. 06 - .12,5 -.1 25 . 0 5b . 08 . 05 . 04 5+ .oo -. 2 0 .1 0 . 07 12 15 35 5 10 .b r= 4 nn - . 04 -. 0 7 . 05 r:. o.) 4.5 12 27 ?.,v 25 , r-, .2 8 .2 8 open .12 open .16 .54 1.20 . 30 .72 open . 0 6 . 2 ..,,;: . 64 1. 00 1.42 open . 04 .24 . 54 . 40 . 90 .14 . 90 open . 08 . 42 .G B c..) <.) • Depth over Jisc lip feet open .1 0 op en :,0 open . 02 1. 04 . 88 1.28 open . 24 .02 .27 . 58 .s2 open .1 0 op en .1 0 open . 06 open .1 6 open . 27 . 87 open .16 . 08 . 44 . 44 open . 36 :Jep tb OVE:;l" ?ernar}rn T"bn:iat feet .1 2 .16 . 1 ,,;::, . 22 Ho :p rime . 32 Tvvo holes 01) t:TI .14 .12 .43 . 43 .31 .40 . 215 .265 .33 .365 .425 l~o pr i me i min .15 .24 :J losed late .32 5 . 345 . 40 .2 8 . 2·1 :To :prime 30sec . 14 .40 • Z-25 ('\ • 4V .:::75 .42 5 .19 .l G . 28 . 355 45 .1 65 .1 4 .17 .18 .20 . 42 .1 2 .15 .2 6 I:: o prime . 29 .17 • : 1 Jata 2h e et 12 ( continued) i.:c de l II. Top r ead . ft Dep th over Disc l ip feet cp en . 26 1 Bottom read . ft 7 • z ,L~ 6 . 99 7. 3 6 . 92 6 . 92 7 . 08 7.04 6 . 1j6 7 .18 6 . 40 7. 32 7 .18 . 6 .6 0 7.34 7.2 8 6 . 90 6 . 60 6 . 30 5 . g2 7.0 8 6 .7 4 6 . ~2 6 . 00 6 . 00 7.4 7.1 6 . 84 6 . 44 7. 4 7 .1 2 6 .54 7 . c.6 . oo . 04 . 06 -. 0 15 . oo . 03 . 06 - . ()3 . 06 -.1 0 .0 8 .0 4 -. 06 'I ime in prim sea 2.5 20 10 9 24 a., 7 5.5 8 34 6 30 . 08 . 04 - . 04 -. 0 75 -.1 0 5 -.1 5 7 7.5 16 27 20 t OQ:, 9 -. 035 -.2 05 16 9.5 • V -.J Z -.1 4 -.11 . 09 -. 0 2 -.1 0 5 -.10 . 04 -. 0 7 s low .06 10 2 6-7 l fi 2 5.5 20 . 09 op en . 22 .1 6 .16 . oo . 04 .1 2 op en .1 0 . 6 Fl op en • 24 op en .1 0 . 48 open . 2 6 open .2 0 .1 8 .4 8 .78 1.16 .oo • 2,4 .66 1. () 8 1. 08 o pen . 3 2 op en . 02 . 24 64.open . i 2 op en • 0 4. . 54 ope n . 18 . Dcptt ove r Throat feet =~E.; rr,arks .22 .l E .16 .2 35 . 22 .1 9 .1 6 .25 .1 6 .32 .14 Ne prime .1 8 .2 8 .1 4 No prime 35sec .18 .26 .295 . 325 .37 .1 9 h r· • 2 uD . 425 . 35 No r,rime . z.5 . z.3 .1 3 . 24 . :?:>35 . 32 .1 8 .2 s .I 6 no _p ri n;e DATA S}LET 14 .. _,:ode l I. Siphon drawing some air at times. Q = 3 .5 second feet. Condi tfons--tbree "U" mercury colurr.ns, othere "U" water columns. Date--June 19th 1916. Pt Sec. or ar E: a '.l.' ut in no so,f't 11 Vcl. in ft/sec v2 2g Inl .'765 1 . 465 4.57 7.52 lb.42 15.3 .32 ,88 • 22 7 3 . 63 . 22~ . 2155 16.25 4.10 .1975 17.7 3 4.88 - . 54 • 2:7 2 15.1 7 . 254 13.78 2.94 8 • 290 12.07 2.26 9 .318 11.0 1.88 10 .348 10.06 1.57 8.73 1.18 11 .401 :Disc. Vel 8.73 1.18 2 3 4 5 6 ... -w D rri . Vl . z N retEfr. ...... ube 10 cols .oo -r1 r J.•. \ ! • Gage reaa ft .54 .oo >I~ DaSh2 j 10..f,! 6.46 6.46 Los t ±1v 2 Head 4r2g aprox teet aver. 1.9 - . 93 6.03 4.8 -4.43 6.63 5.2 -5.07 6.87 5.76 -5.3SJ 6.63 8.02 -7.05 6.03 5.24 4.85 5 .4t~ 4.9 4.8 .30 2 .10 2.75 1.39 5.61 J,J9 Eff. exp. for disctarge through throat 3 . = 3.5 --------;:::======--• . 845 = [34 . 5,0 .229 X 8 .025 X ~5.61 - .54 Eff. exp. for smallest section 5. = 3.5 .1975 X 8.025 X ✓ 5.61 - = .980 . 54 =.021 DA'l'A SlIBE'I 15 .. :-.1odel I Q (quantity) - 3.55 second feet. Siphon drawing some air at times. Condi tions--:-four mercur;y water columns, also 11 11 ur 1 tu·bes, others U • 11 Date--June 2 h i t 1916. Pt Sec. or area Yel. V2 in 2g Tub ft/sec in no sqft reiliY. z Lost Head m.&me ube 10 ft cols ft feet '±age read p w .oo 6 .45 .55 .40 4. 64 .33 Inl .765 -.88 G.03 1 .465 7.6? .905 1.85 .30 2 .227 15.64 3.80 5.05 -4.68 6. 6~"J .40 cl. .229 15.5 ~.73 5.37 -5.24 6.87 .53 4 .2155 16.47 4.22 M6.40 -6.0Z 6.63 1.17 5 .1975 17.97 5.01 M8 .Z6 -7.39 6.0 3 .46 .232 15.3 3.63 M7.44 -5.2Ci 4. 8 5 6 .08 7 .254 13.S6 3 .03 M6.92 - 3 .29 3.~7 8 .290 12.2 3 2 . s 2 6.4 ? .53 1.22 Z.68 9 .31 8 11.15 1.93 5.25 2.05 o.oo 3.66 10.2 1.61 4.S5 10 , .t'.48 2. 65 - . 55 z,. 32 8.87 1.22 4.9 11 .401 -------------------1.22 Discharge Velocity Lost Head 1.24 1.24 T . W. 5.76 1 V Eff. exp . for disct a r 3 e through throat 3 = 3 55 ---=-~----=----=--:-:-•-- --;:;:::::;:::;====:;;;:;:... = • 84 7 = 84. 71 .229 x 8.02b ✓ b.76 - .55 0 X Eff. e:xp. for smallest section 5 = z,. 55 .1SJ75 x 8.02b :x ✓ b.76 - .55 Q = 3 . 44 f Con d i t i on E: --th~-'e~ inv e rt ec1 ~hate r co l umn s suc k i ng fr om '.l.' . W. a n d one me r c ur y c ol umn ( l a t er cbang Ec ll to i n v er te d wa te r) . Suc k inf sornt e_i r o cccs io na lly ---.0a t e , June 22n d 1 ~16. <) Pt Sec or ar ea tub in n o sqf t ii . \V. I nl . 765 1 . 4 65 2 .2 27 3 • 22 9 4 .2155 5 .1975 ,7· (., (' ..,age 2g re a d Na . &me col s it 'l e 1. in ft/se c z 1 f ee t .oo 0 . 61 .31 . 89 - 1.60 o . 57 4 . 9 15. 04 3 .52- 5.05 15.97 Z .96 -.43 17.41± ..: .72 -2.24 6 .2 3 2 14. 84 3 .4 3 .75 7 . 2 54 1 3 . 5 5 2 . 85 2.60 8 . 290 11. 87 2 .18 4 . 20 9 . 318 10 . 82 1. 82 5 .1 10 . 348 9. 8 9 1. 5 2 4 . 8 11 . 401 8 .5 8 1.14 4 .7 Disc. Ve lo c --- - 1.14 -4 .50 7 .5 5 15.15 T . 1.H• Lost head. refer. tub e 1 f e et -.6 3 6 . 03 4 .5 3 6.6 3 -4.92 -5.76 6.87 6.6 ~ -7.57 6.03 -4.58 4. 85 - 2 .7 3 3 . 37 2 .07 -1.13 .6 8 2.2 1. 2 2 2 . 85 -.55 .oo 1.67 5. 3 3 Eff . exp . f' o r d i E!c ha r g e t h r ougt 1.67 thr oa t 2 . = 2 . 44 - - - - -- - ---;::=::========--= . 662 = 86 . 2;,o • 22 ., , (; ;; X C; c, • 02-~D rr. X ,./r \I LJ • ~: .) ~1 • O - Ef f . ex p. f o r d i s cha r ge throu gh sma lle s t 3 . 44 .1 976 X 8 . 025 X ~ 5. 33 - .61 Tes t with one tub e oi e n = = 1. 00 = 10010 = H . ..v. . 05 T. VV. ;; 6 . 3 0 H = 6. 25 i e e t. 3. 34 Lfi . s ma ll es t area = s e c t i on 5. : 07 2 7 = 7 2 .7 /v = •843 = 64 . t/o DA TA SI-IE:~~; . , 17 Model II Q = 3.5 second feet Sirh on c1rawinz some air. Condi tions--f'i ve inverted_ water columns, others 11 Un col urrmz. Pt Sec. or area tub in no sq.ft. ,r2 , Ve 1. in 2g ft/ sec G-age p read w watr cols ft 0.56 Inl • 765 1 .465 6 4.57 7.53 . 227 15.41 .229 15.28 .2.155 16.25 .1S75 17.72 .232 15.1 V. 7 • 254 2.94 2 3 4 5 Lost flv 2 ·_t-1' c , acl 4' r2g "' z re fei: tube 1 feet ft f=.021 .oo 6.44 6.44) -.48 -4.43 -4.87 6.03 6.63 6.87 6.63 6 4~) 5:sg)) 5.63_) 5.14 .324 .88 1.45 3 .69 3.63 4.80 5.0 0.05 4.10 4.87 •-LL D 6. O'.?\~ 7_ .01 .01 .54 .26 .07 .14 .15 .18 .26 .23 .4 ~ J'.94 . ., . ., 6 y ,;, 0 -4.19 4.85 4.20 -2.44 3. 3 ? -:.87 ~ .14 8 .290 12.06 2.26 5.18 -.46 2.07 ..-:,.87) .10 .O? 9 . 318 11.0 .88 4.7 1.08 1.22 4.l~J/ .07 10 .348 10.05 1.57 4.4 2.60 .oo 4.17 Discharf E Velocity Head Lost (approx) --------- 1.5oi .02 T. W. 5. 64 1.36 1.36 1.32 Total 12 .77 1 i;;( .,i. 1.45 -5.59 - 6 . Oil. ., -· aprox aver. ~.2 Eff. exp. for discharg e tbrough th:r-oat Z = 3.5 = • 84 i5 = 84 • 5fv .229 X 8.025 X ~5.64 - .56 Eff. exp. for discharge through smallest section 5 = 3.5 - • 56