Experimental and Numerical Studies of Diamond-Shaped Injector in a Supersonic Flow

摘要

A series of mixing and combustion tests using a diamond-shaped fuel injector were conducted in a Mach-2 freestream. The goals were to 1) visualize the structure of the LCVP and 2) assess reactivity in the LCVP. The tools employed include PLIF of the OH and NO molecules and complementary 3-D nonreacting simulations. The specific findings are summarized as follows:rn1) The NO-PLIF images captured the 3-D structure of the LCVP for the first time, and this structure corresponded well with the prediction by the 3-D numerical simulations.rn2) OH consumption in the LCVP was clearly observed when ethylene was injected from the diamond port and the fuel-lean upstream torch was applied, but intensive combustion and heat release were not attained.rn3) Combustion suitable for flame holding was not observed within the LCVP. This observation was consistent with our 3-D CFD simulations, which indicated that under the present operating conditions, the pressure and temperature were both too low, and the gas composition within the LCVP was very fuel-rich.