Numerical Simulations of a Scramjet Isolator Using RANS and LES Approaches

Abstract

The internal, compressible, turbulent flow through a scramjet-isolator configuration is presented, with the primary goal being to better determine the shock train leading edge location of a typical Mach 2 nozzle-isolator configuration. Both 2D and 3D approaches are utilized, in conjunction with a variety of different turbulence models taken from both RANS and filtered models. The effects of inlet turbulence, as well as the use of grid adaption techniques are evaluated under the 2D assumption and render certain simplifying assumptions valid for the 3D cases. Experimental comparisons reveal that the RANS approach best conform to experimental observations, while the LES approach showed the most degree of disparity. Further LES simulations are warranted however, particularly since these were performed without the aid of density based solvers, which greatly facilitates the prior to the inception of a new FLUENT release, (version 6.3) which contains several improvements over previous releases with respect to compressible, turbulent flows.