Numerical investigation of a mass injection probe used for the determination of high enthalpies

Abstract

New materials for thermal protection systems of re-entry vehicles are usually tested extensively in plasma wind tunnels. For this purpose the Institutfur Raumfahrtsysteme (IRS) operates the plasma wind tunnels PWK1 and PWK2. One of the most important parameters during testing, besides test specimen surface temperature and pressure, is the total specific enthalpy of the flaw, i.e. the specific energy content of the flow in which the probe is placed. A new measurement technique using a mass injection probe was developed for the experimental determination of this specific enthalpy -within the high enthalpy flows of the PWK's. Additionally, a numerical simulation of the high-enthalpy flow is necessary because not all parameters are experimentally achievable. For this, the three-dimensional, axisymmetric program system SINA (Sequential Iterative Non-equilibrium Algorithm) has been developed in the frame of the Collaborative Research Center „ High-Temperature Problems of re-entry vehicles (Sonderforschungsbereich 259 'Hochtemperaturprobleme riickkehrfdhiger Raumtransportsysteme'). This paper presents first results of the application of the code on the newly developed enthalpy probe. The basic features of the methods, the results obtained for the flow about the mass injection probe, and the comparison with the experimental data as well as the theoretical investigations are presented.