RANS analysis of merging supersonic streamwise vortices for enhanced mixing in scramjet combustors

Streamwise vortices are studied as a mixing enhancer for scramjet combustors due to their insensitivity to compressibility relative to spanwise structures. A specific merging interaction between supersonic corotating vortices has been shown in experiments to sustain turbulence production against decay. In this paper this interaction is investigated numerically to determine how well it can be replicated with a RANS approach, and the effect of increasing the Mach number. The shape and rotation of the merging vortices appears similar to experimental results. The decay of vorticity follows a similar trend to experimental results, however the vorticity was higher in the RANS results. At higher Mach numbers the merging process appears to be pushed further down the domain.