Comment on 'Lower bounds on deformations of dynamically loaded rigid-plastic continua.'

Abstract

In general, a three-dimensional shock wave-boundary layer interaction can be viewed locally as a two-dimensional one with cross flow and mass transfer—a result of the scavenging vortex in the three-dimensional case. This interpretation is supported by experimental evidence which shows that the extent of a separated flow region is considerably greater for laminar than for turbulent flow for three-dimensional shock-wave/boundarylayer interaction as well as for the two-dimensional case. Thus, in retrospect, it is reasonable to expect a sharp change in the flow separation line as a skewed impinging shock crosses a region of boundary-layer transition. Conversely, a sharp change in an otherwise smoothly curved separation line on a planar surface is most likely indicative of transition because, in the absence of other disturbances in a flow, there is no physical mechanism whereby a shock generator of simple geometry should produce a distorted separation line. References 1 Korkegi, R. H., Survey of Viscous Interactions Associated with High Mach Number Flight, AIAA Journal, Vol. 9, No. May 1971, pp. 771-784. 2 Young, F. L., Kaufman, L. G., II, Korkegi, R. H., Experimental Investigation of Interactions between Blunt Fin Shock Waves and Adjacent Boundary Layers at Mach Numbers 3 and 5, ARL 68-0214, Dec. 1968, Aerospace Research Labs., Wright-Patterson Air Force Base, Ohio. 3 West, J. E. and Korkegi, R. H., Interaction in the Corner of Intersecting Wedges at a Mach Number of 3 and High Reynolds Numbers, ARL 71-0241, Oct. 1971, Aerospace Research Labs., Wright-Patterson Air Force Base, Ohio; also AIAA Paper 72-6, San Diego, Calif., 1972. 4 Kaufman, L. G. II, Meckler, L., and Hartofilis, S. A., An Investigation of Flow Separation on Aerodynamic Controls at Hypersonic Speeds, Journal of Aircraft, Vol. 3, No. 6, Nov.-Dec. 1966, pp. 555-561.