Measurements on a flat plate consisting of SiC- and C-SiC-materials in a high enthalpy flow field

Abstract

Although the arc heated wind tunnel LBK, because of its low density level, is not convenient for a simulation in the aerodynamic sense, its long testing time allows to analyse gas-surface interaction phenomena. Tests have been performed using a water cooled flat plate consisting of Cu, SiC and C-SiC materials at angles of attack of zero and nine degree. All tests have been carried out at a mass flow rate of 50 g/s and a reservoir pressure of 1295 mbar. Axial and radial Pilot pressure profiles in the free stream and the pressure distribution on the flat plate have been measured. Heat flux rates have been determined by means of heat flux probes, which are mounted adiabatically in the plate. The surface temperature has been measured by a pyrometer or an IR-system. Emission and absorption spectroscopy technipues have been applied to determine rotational and vibrational temperatures as well as the concentration of NO in the free stream and near the flat plate. Measurements have been supported by numerical computations using a numerical code providing frozen, equilibrium and non-equilibrium flow solutions. The quasi-one dimensional inviscid flow solution is coupled with a laminar boundary later solution. Pressure and heat flux distributions along the flat plate have been computed and compared with experimental results.