Experimental investigation of flow past simple model bodies in hypersonic wind tunnels at similar values of the Mach and Reynolds numbers but at different physical flow velocities

The pressure distributions over the surfaces of simple model bodies, such as hemisphere, wedge, and cone, and the bow shock stand-off distances from these bodies are investigated in hypersonic wind tunnels with similar-in-value Mach and Reynolds numbers but considerably different flow velocities ( u = 790 to 5950 m/s). These are the tunnels with an ohmic heater and electric-arc and MHD gas flow accelerators. Flow pattern visualization followed by photometering measurements are used for determining the bow shock stand-off distance. At low gas densities the method of anomalous dispersion of the sounding radiation is employed for visualizing the flow. The pressure distributions over the body surfaces and the bow shock stand-off distances are calculated from the Navier-Stokes equations and thin viscous shock layer (TVSL) theory. The measured parameter values are in agreement with those calculated from Navier-Stokes equations. For the cone and the wedge the discrepancy is within 10%.