Numerical Study for Flow Behavior and Drag of Axisymmetric Boattail Models at Different Mach Number

In this study, flow behavior around an axisymmetric boattail model was presented at different Mach number from subsonic to supersonic flow. Reynolds averaged Navier-Stokes equations with k-ω SST model was applied for the simulation. Results were validated with previous relevant experimental data for validation. The results indicated that the numerical model can provide high accurate results. The differences in drag coefficients of the current and relevant studies is less than 3. Pressure distribution showed that at supersonic flow, pressure becomes nearly flat on the boattail surface due to generation of shock wave. Skin-friction indicated separation bubble is formed only for low-speed conditions at boattail angle of 14°. At higher Mach number, separation positions occurred at the base edge for all models and flow conditions. The pressure trend, position of shock wave, and flow pattern around the model was indicated details in this study. The relation between shock-wave structure and drag of the model was obtained. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.