Experiments on Thin Airfoils Spanning a Transonic Shear Flow

Citation

Cosner, Raymond Robert (1976) Experiments on Thin Airfoils Spanning a Transonic Shear Flow. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/YJNQ-ZP43. https://resolver.caltech.edu/CaltechETD:etd-11292006-134453

Abstract

A wind tunnel was built at the California Institute of Technology to provide two uniform coflowing streams at Mach numbers of 0.6 and l.4 with a plane mixing layer in between. Preliminary studies were made of this free shear layer, indicating a region of self-similar behavior and general agreement in growth rate with previous studies. A program of experimental and theoretical work was completed in which wedges were installed in the supersonic stream to create shock waves incident on the shear layer. Similar studies were performed with wedges in the subsonic stream. Good agreement was found between the analytic first-order theory and experiment in showing that the upstream propagation of pressure disturbances ahead of their source in the uniform subsonic stream is limited to about 0.6 subsonic layer thicknesses. The problem of an airfoil in spanwise-varying transonic shear was studied experimentally with the goal of understanding the interactions in the shear region between the supersonic and subsonic streams, especially in terms of deviations from quasi-two-dimensional behavior. The effect of modest angle of attack was also examined.

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