Diagnostic Tools for Plasma Wind Tunnels and Reentry Vehicles at the IRS.

摘要

Various plasma wind tunnels have been built for developing reusable space transportation systems and space probes entering the atmospheres of celestial bodies. All together they cover almost the whole reentry trajectory of a space craft 1.1. They generate continuous plasma flows of high specific enthalpy and velocity with thermal or magnetoplasmadynamic generators. Plasma wind tunnels are used for: development and qualification of radiation and ablative cooling materials and thermal protection systems, validation of numerical codes for reentry prediction and development and qualification of reentry measurement devices. The accuracy of the simulation of reentry conditions strongly depends on the ability to determine the flow conditions. These three lectures give an overview of the diagnostic methods which are qualified and in use at the IRS. Both intrusive probe measurement techniques (part A) including mass spectrometry and non-intrusive, optical techniques (part B) such as emission spectroscopy and laser induced fluorescence (LIF) are used to investigate high enthalpy plasma flows. Several measurement techniques are being developed for flight application (see part C). The minimum set of parameters which have to be duplicated during the tests for material qualification (see Fig. 1.1) are the specific enthalpy of the gas, the stagnation pressure and the surface temperature in the case of a radiation cooling material, or the heat flux for an ablative material. This is a minimum set of parameters which has to be adjusted during the test. A whole series of probes and non-intrusive techniques were developed to determine these parameters.