Fundamental Studies on Heat Load of High Enthalpy Shock Tunnel. 1st Report. Numerical Analysis Method and Its Prediction Accuracy for a Flow Field.

Abstract

It is very important in high enthalpy shock tunnels to predict heating conditions of the shock tube end where the tube wall is exposed to high temperature. The final goals of these studies are to establish methods to predict thermal conditions to which a tube end is subjected, and to develop thermal protection which will be suitable for high enthalpy shock tunnels. In the present report, a numerical flow analysis method combined with a heat conduction analysis of tube wall was developed to calculate the flow and wall terperature conditions in a shock tube. A numerical procedure was proposed which includes calculation of the mixing region of driver and test gases, and a friction factor model is presented which considers the change of visconsity under high terperatures. Experiments were carried out using the free-piston shock tunnel T5 of the California Institute of Technology. Comparison of calculated and experimental results of pressure histories in the shock tube showed that the present computer program has enough accuracy to calculate the flow field at the shock tube end.