NASA SP.


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NASA Technical Note


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Theoretical and Experimental Longitudinal Aerodynamic Characteristics of an Aspect Ratio 0.25 Sharp-edge Delta Wing at Subsonic, Supersonic, and Hypersonic Speeds


Book Description

The suction analogy concept of Polhamus for predicting vortex lift in conjunction with an appropriate potential-flow solution is called the present method. This method is applied herein to an aspect ratio of 0.25 sharp-edge delta wing from a Mach number of 0.143 to 10.4 in free air and at 0.074 in ground effect, and also to an aspect ratio of 0.35 triangular cross-sectional body at Mach number of 6.9. The models had subsonic leading edges at the test Mach numbers. Vortex-flow effects could be neither confirmed nor denied to exist at high speeds because of the lack of flow visualization above a Mach number of 0.143. The data, however, could be better predicted by including a vortex-flow effect, although not always to the extent predicted from the present method because of the presence of actual and hypothesized unmodeled flow situations.