Kinetic Modeling of Traverse Jets in Hypersonic Flow Over a Cone

The interaction of a side jet with incoming hypersonic flows at M=6 and M=12 has been modeled using direct simulation Monte Carlo (DSMC). The geometry is a 7 half angle cone that has been used in several experimental studies in the literature. The presence of the jet creates several shocks, shear layers and recirculation zones and it is observed that in these shocks and shear layers continuum breakdown occurs. In addition to these high gradient layers, continuum breakdown occurs within the jet expansion itself which strongly affects the interaction region. The presence of continuum breakdown even though free stream conditions are continuum suggests the use of a kinetic method such as DSMC. We observe many of the classical shock structures that are discussed in the literature for both Mach numbers. The presence of the jet causes the drag force and heat transfer to decrease and normal force to increase in all cases. The interaction of shocks, shear layers and boundary layer causes unsteadiness in the shock system. The frequencies related to this unsteadiness were found to agree with those in the literature which increase with Mach number but are mostly insensitive to the Reynolds number. It is also observed that this low frequency unsteadiness in the shock system causes the local surface properties to be unsteady with very high fluctuations especially near shock interaction and separation regions.