Effect of fuel temperature on mixing characteristics of a kerosene jet injected into a cavity-based supersonic combustor.

This article investigates how kerosene injection temperature affects the mixing, evaporation, and ignition characteristics of a liquid kerosene jet in a cavity-based supersonic combustor, using compressible two-phase flow large-eddy simulations (LES) based on the Eulerian–Lagrangian approach. The study finds that higher kerosene injection temperatures transform the jet flow field to resemble a gas jet in supersonic crossflow, strengthening the wall counter-rotating vortex pair (CVP), enlarging the cavity recirculation zone, and increasing kerosene vapor entrainment into the cavity. This leads to a higher local fuel equivalence ratio exceeding stoichiometric levels and a reduced cavity temperature due to the cooler kerosene vapor, which together prolong ignition delay time and can cause ignition failure, consistent with experimental observations. The results highlight the complex interplay between fuel temperature, flow structures, and ignition performance critical for scramjet combustor design and operation.