Simultaneous PIV and PLIF Measurements of Mach Number Effects on Single-Interface Richtmyer-Meshkov Mixing

摘要

First measurements from the VST of simultaneous velocity and concentration for RMI are presented. The RMI is studied for two Mach numbers (Ma=1.21 and 1.29) for a statistically invariant, multi-modal single interface (air-SF_6). RMI mixing dependence on Mach number results indicate spatially averaged vorticity, streamwise Reynolds normal stresses u_1'u_1'/u~2, and turbulent kinetic energy within the mixing interface increase with Mach number. The span-wise normal and shear Reynolds stresses (u_1'/u~2 and u_1'u_2'/u~2, respectively) are similar in magnitude for both Mach numbers. A broad spectrum of length scales are observed for both Mach number cases. While strong concentration gradients exist at the low Mach number interface, improved and more uniform mixing is observed for the higher Mach number case. Improved PLIF post-processing and Increased measurement samples and locations are proposed for more quantitative assessments of small-scale mixing due to Mach number.