Effect of inlet diameter on the flow structure and performance for aluminum-based water-jet engine

Abstract In this study, the flow field and performance for the aluminum based water ramjet was analyzed through numerical simulation. The time decrease in evaporation heat absorption process expands the range of aluminum/water combustion and increase the specific impulse. If the diameter of atomized water droplets from the primary inlet is large, the evaporation efficiency will be further reduced, which is not conducive to the further propagation of the reaction. However, if the diameter is small, the flow field temperature will be rapidly dropped due to rapid evaporation, and a large range of low-temperature areas will appear in the reaction area of the combustor. The diameter reduction of atomized water droplets from the secondary water inlet is conducive to the diffusion of the reaction area downstream, further and makes the combustion range be expanded. This effect is benefit for increasing the specific impulse and can reduce the temperature near the wall.