Mixing characteristics of liquid jet injected behind a curved pylon in supersonic flow

Abstract

Mixing of liquid jet in Mach 1.71 crossflow using a curved pylon configuration has been studied experimentally. The liquid acetone jet was injected at 60° against the free stream airflow behind the pylon. High-speed Schlieren and Mie scattering experiments were performed to evaluate the mixing characteristics of liquid jet injected behind the curved pylon. POD and SPOD analyses were employed on the high-speed Schlieren images to observe the coherent structures, their energy levels, and frequencies at which these structures occur. Results showed improvements in penetration height and the lateral spread of liquid jet for the curved pylon configuration. The penetration height of the liquid jet was 7.79% more for the curved pylon case as compared with the standard pylon case for the same momentum flux ratio. Further increase in the momentum flux ratio increased the penetration height to 15.53% more as compared with the standard pylon case. The spread area of the liquid jet was 17.42% more at x/dj=25 and 25.97% more at x/dj=40 for the curved pylon case than the standard pylon case for the same momentum flux ratio. The presence of counter-rotating vortices at the top of the liquid plume and in the near-wall region caused a higher spread area in curved pylon cases as compared with standard pylon cases.