Turbulent free jet theory for prediction of high-enthalpy and low pressure flows

Abstract

This article presents an extension of the well-known turbulent free jet theory to high enthalpy and low pressure flows. These flows are produced in plasma wind tunnel facilities in order to simulate the first phase of the reentry of space vehicles. It is shown that the semi-empirical results obtained from turbulent free jet theory of cold gases are partly transferable to the high enthalpy flows. The theory is simplified in that way that it is possible to obtain analytical equations for the description of the jet behavior. The theoretical prediction according to this turbulent free jet theory is compared with different experimental test cases showing generally a good qualitative agreement An extensively studied high enthalpy nitrogen test case is taken for the quantitative comparison showing also a good agreement between theory and experiment