Numerical investigate on flow process and mixing characteristics of hydrogen/aluminum powder two-phase fuel under different inlet and injection conditions

Abstract

The flow and mixing process of a hydrogen/aluminum powder two-phase fuel transverse jet in a supersonic cross flow are simulated in this work using the Euler-Lagrangian scheme. The effects of the inlet Mach numbers (Ma) and jet-to-crossflow momentum flux ratios (J) on the mixing process and flow characteristics of the gas-solid two-phase fuel are investigated. The results show that there are substantial differences in the flow and mixing properties of the two-phase fuel consisting of hydrogen and aluminum powder. While the powder fuel has a minimal impact on the flow field, the interaction of the hydrogen jet with the supersonic cross flow creates complex wave structures in the flow field. Hydrogen is influenced by the large-scale structures of the counter-rotating vortex pair (CVPs) and surface-trailing counter-rotating vortex pairs (TCVPs) in the flow field. In contrast, the powder fuel is influenced by various initial conditions, including the momentum of the hydrogen jet, the momentum of the supersonic mainstream, and the size of the combustor. The mixing efficiency of hydrogen is 7.381%–33.933 % higher than that of the powdered fuel under the same inlet and injection conditions. The comparison showed that the mixing efficiency of hydrogen decreases with the increase of injection momentum and inlet Mach number, while the mixing efficiency of powder fuel increases with increase of injection momentum and inlet Mach number. Among them, the mixing efficiency of hydrogen and powder fuel under the conditions of Ma = 1.6 and J = 0.86 are 0.63 and 0.29, respectively. The mixing efficiency of hydrogen and powder fuel under the conditions of Ma = 3.0 and J = 1.72 are 0.48 and 0.41, respectively.