Mixing of a Hydrogen Jet from a Wedge Shaped Injector into a Supersonic Cross Flow

Abstract

A new measurement by using a catalytic reaction on a platinum wire was conducted spatially to evaluate a mixing condition in a supersonic flow field. A spatial mixing field was created by a transverse hydrogen jet injected into a cold supersonic cross flow (Mach 1.81) through a wedge shaped injector. The half-vertical angles of 8° or 18° were chosen as that of the wedge shaped injector. These results were compared with that of a circular injector case. The results showed that this method could evaluate a spatial mixing condition. The results also clarified that a jet plume in the cases of wedge injectors penetrated higher than that of the circular injector case and separate from the lower wall when going downstream. To observe jet/supersonic flow interaction, Schlieren visualization and oil flow visualization were carried out. It was shown that the extent of the separation region around the 8° wedge injector was the smallest among those injectors. Pitot pressure measurements were also conducted. These indicated that a wedge injector scheme was more beneficial than that of a circular injector for the supersonic combustion and combustor wall cooling.