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.

Interaction between Supersonic Cavity Flow and Streamwise Vortices for Supersonic Mixing Enhancement

“…To improve the mixing in supersonic condition, several types of ramp injector have been proposed [3][4][5][6][7][8][9][10][11] . Ramp injectors are beneficial to the mixing performance due to the generation of streamwise vortices, which increase the fuel penetration and the fuel/air contact surface 12) .…”

Numerical Study of Injected Jets into Supersonic Main Flow from a Porous Cavity

“…2) It revealed detailed flow feature and shock wave topology in the vicinity of the wall normal porthole injection. F. Sakima et al 3) investigated wedge shaped injector into a supersonic cross flow, which revealed that the difference between circular injector and wedge injector in terms of a total pressure loss and a separation region around the jet. A technique using lobed strut induced streamwise vorticity was reported by P. Gerlinger, et al.…”

Correlation between Mass Flux Fluctuation and Fluctuation of Hydrogen Concentration in 2-D Air-Hydrogen Supersonic Mixing Layer

“…3,7,[11][12][13][14][15][16][17] We used it to investigate the timeaveraged mixing conditions of the 2-D hydrogen-air supersonic mixing layer in previous studies. 15,16) We clarified that…”

“…For example, the freestream remains supersonic in the combustor, so mixing of fuel jets with the freestream must be quick. Some injection schemes to enhance the mixing for the SCRAMJET have been suggested, [2][3][4][5][6][7][8][9][10][11] such as wedge shaped injector schemes 2,3) and their derivations, 4,5) rampinjector schemes 6,7) and their derivations 8,9) and inclined-injector schemes. 10,11) It is important to evaluate the mixing condition in the SCRAMJET in order to suggest or develop these injection schemes.…”