Comparisons of computations with experiments for electron transpiration cooling at high enthalpies

A modeling approach for electron transpiration cooling of high enthalpy ight is compared to a set of experiments performed in a plasma arc tunnel for nitrogen and argon. The comparisons include nitrogen and argon ow at high enthalpies, 12,000 btu/lb and 5,000 btu/lb respectively, with a Mach number of 2.5 to 3. Converting the provided enthalpies and Mach numbers to freestream temperatures and velocities is discussed. The numerical approach is described including implementation of a thermionic emission boundary condition. Also described is the implementation of a finite-rate chemistry model for argon ionization. Different emissive materials are also investigated including graphite and tungsten. The comparisons include two different geometries with different leading edge radii. The numerical results produce a wide range of emitted current due to the uncertainties in freestream conditions and emissive material properties, but still agree well with the experiments. Future work recommendations are provided that may improve the physical accuracy of the modeling capabilities used in the comparisons.