Development of a Hybrid Method to Characterize Aerodynamic Performance of Finned Missiles

Full Reynolds-Averaged Navier-Stokes (RANS) simulations around finned missiles operating in high Mach number regimes are extremely computationally expensive to obtain. This study looks into the efficacy of combining a full RANS simulation with space marching RANS- a technique where the computational domain is divided into planes in the streamwise direction and solved sequentially. By leveraging the primarily hyperbolic structure of supersonic and hypersonic flows, a computational solution comparable in accuracy to a full RANS simulation that takes up much less computational resources and time can be realized. The missile geometry is divided into two regions and exported as separate CAD files. Meshes are then created around the CAD models. The forebody of the missile is solved using space marching RANS, while the rest of the missile, including the fins, boattail and wake region is solved using full RANS. The two simulations are coupled using a self-written C++ interpolation code, creating the effect of the flow passing right through the first mesh, and into the second. The combined solution can be used to study flow around the missile, and calculate non-dimensional aerodynamic coefficients such as coefficient of lift, drag coefficient, and various moment coefficients.