An Experimental Investigation of Flow over Simple Blunt Bodies at Mach Number of 5.8

Citation

Wisenbaker, Eugene Morgan (1957) An Experimental Investigation of Flow over Simple Blunt Bodies at Mach Number of 5.8. Engineer's thesis, California Institute of Technology. doi:10.7907/0KC4-4827. https://resolver.caltech.edu/CaltechETD:etd-08062004-154112

Abstract

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. Shock stand-off distances and shock shapes were measured and/or observed for a series of 14 blunt-nosed bodies at a Mach number of 5. 8 and Reynolds number per inch of [...]. Nine of these bodies had hemisphere-segment noses designed to include the entire range of possible nose radii of curvature from flat-faced to hemispherical. Two models characterized by sharp shoulders and concave hemisphere-segment noses were also tested. Three additional models representing the round-shouldered, flat-faced type completed the set of 14. All models had cylindrical afterbodies 1.50 inches in diameter, and were yawed at angles of 0, 4, and 8 degrees. Stand-off distances are compared to the theoretical predictions of Hayes, Frobstein, and Heybey where applicable, and shock shape is compared to that given by Hayes for the body with infinite nose radius of curvature. Results of the stand-off distance comparisons varied from under prediction by a factor of two to over prediction by the same amount. Hayes' shock shape approximated that actually observed very closely. It was generally found that body shape in the sonic region greatly influenced the shock shape and stand-off distance. Static pressure distributions were measured on three representative bodies selected as follows: (1) a hemisphere-segment body having a ratio of nose radius to base diameter of 1.30 and falling in the middle of the range from hemisphere to flat-nosed; (2) a flat-faced body with sharp shoulder; and (3) a flat-faced body with a rounded shoulder of 5/16 inch radius. Pressures very close to stagnation values generally were found to be present over a large area of the nose in the case of the flat-faced body. Rounding of the shoulder tended to reduce values of [...] below those observed at corresponding points on the completely flat-faced body, except in the region near the body axis The pressure distributions are compared where applicable with the modified Newtonian approximation and with Probstein's approximation to [...] for zero angle of yaw. Agreement with the modified Newtonian values was generally good near the axis, but deteriorated rapidly in the shoulder regions, except in the case of the rounded shoulder body.

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