Investigation of Wind Tunnel Blockage Effect on Liftoff Aerodynamics of a Launch Vehicle Through Open-Source CFD Solver SU2

Aerodynamic coefficients for a launch vehicle are estimated using wind tunnel tests as well as CFD simulations. Estimation of coefficients at liftoff is often carried out using low speed wind tunnel tests. Presence of tunnel walls affect aerodynamic coefficients due to the blockage introduced by the model to the flow. The effect of blockage is investigated in the current study through CFD simulations with and without wind tunnel walls on a launch vehicle configuration in the presence of launch pad and umbilical tower (UT). It is seen that the aerodynamic characteristics are significantly influenced by the presence of wind tunnel walls. Even though the model blockage is 4%, variation of 8.5% is seen in total force coefficients.