2ND ELECTRIC-DISCHARGE METHOD FOR VISUALIZING 3-DIMENSIONAL SHOCK SHAPES AROUND HYPERSONIC VEHICLES

This paper describes the second electric discharge method for visualizing three-dimensional shock shapes around hypersonic vehicles. The method is based on the following ideas: When an electrical discharge is generated across a shock wave, the shock wave can be seen as a different radiation intensity in the electric discharge. Therefore, the three-dimensional shock shape can be visualized by taking a discharge photograph from the downstream side of the flow. In this paper, the reasons why the different radiation intensity occurs are explained qualitatively by considering the electric field distribution near the shock wave. As examples of using this method, the cross sectional shock shape over a wedge and the cross sectional shock shape around a delta winged semicone are visualized.