Technique of Measuring Transverse Components of Velocity Fluctuations in Turbulent Flow

Author: Zebb, George Keirn

Year: 1943

Degree: Engineer's thesis

Advisor: Liepmann, Hans Wolfgang

Committee Member: Unknown, Unknown

Option: Aeronautics

DOI: 10.7907/H56H-BX29

Abstract

The mean speed characteristics of several X-type v'/U-meters having widely varied dimensions were measured in order to verify assumptions usually made regarding the range of linear characteristics for meters of this type.

Using the same meters, and other meters with intermediate sizes, values of v'/U were measured in the turbulent fields behind three grids. Comparison of the results gave a qualitative indication of the effect of meter size on turbulence measurements.

A length correction for the X-type meters used was derived and the turbulence values corrected, with the result that all meters gave approximately the same answers.

However, even after application of the length correction, it was found that in the turbulent field behind grids (generally assumed to be isotropic) v'/U was consistently lower than u'/U at a given distance behind the grid. This result is the same as that described by Corrsin in ref. (4) where no length correction was applied.

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