Experimental Investigation of Shock on Shock Interactions in the High Enthalpy Shock Tunnel Goettingen (HEG).

Abstract

The outcome of an experimental investigation of Shock on Shock Interactions, created when an oblique shock impinges on a bow shock formed in front of a circular cylinder in a high enthalpy flow of 20 MJ/kg is presented. This interaction is known as Edney type of interaction. The current study concentrated on Edney types III and IV, where the real gas dissociation effect results in the bow shock being much closer to the cylinder than in case of a perfect gas at the same incident flow Mach number. Flow field pictures as well as pressure and heat transfer distributions on the cylinder are shown. The jet flow behind the bow shock, typical for the type IV interaction, was not observed and the peak pressure and heat loads are much less severe than was expected from the previous ideal gas investigation. Under the investigated flow conditions, the type III interaction can lead to heat transfer and pressure loads as high as those observed for the type IV interaction.