An Investigation of the Effects of Angle of Attack and Airfoil Model Size on the Occurrence of Shock Waves in a Two Dimensional Wind Tunnel

Authors: Chambers, Lester S.; Doll, Raymond. E.; Harrell, Dewitt A.

Year: 1944

Degree: Engineer's thesis

Advisor: von Kármán, Theodore

Committee Members: von Kármán, Theodore; Puckett, Allen E.; Liepmann, Hans Wolfgang

Option: Aeronautics

DOI: 10.7907/NFP2-EG08

Abstract

This paper presents the results of an investigation of the flow in the vicinity of one of the newer symmetrical NACA laminar flow airfoil sections at and above the orbital speed of the section, in the form of schlieren photographs and wall pressure distributions. The investigation was carried out in a two dimensional tunnel, designed for this purpose by the authors, at the Guggenheim Aeronautical Laboratory of the California Institute of Technology during the spring of 1944.

The formation and variation of the shock waves with angle of attack and Mach number are presented in a series of high speed photographs. An attempt is made to indicate the effect of model size in a tunnel of fixed cross sectional area by presenting photographic results of the tests on airfoils of 2", 4", and 6" chord lengths.

Curves of C[subscript L] versus Mach number at constant angle of attack are presented for the three airfoils.

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