Mitigation of Ignition Overpressure in Launch Pads via Unsteady Adjoint-Based Optimization

The solid rocket boosters (SRBs) of space launch vehicles generate powerful Ignition Overpressure (IOP) waves during the early stages of lift-off. These IOP waves propagate through launch environment and are reflected back from the Flame Deflector (FD). Reflected high-amplitude waves can damage the vehicle and the sensitive payload. Computational Fluid Dynamics (CFD) simulations plays a vital role for capturing the pressure waves accurately for launch process of both new and existing space vehicles. There are various ways to decrease the effects of the IOP; one of which is optimizing the flame deflector geometry to deflect the flow away from the rocket. In this study, a flat plate FD geometry inclined at 45° angle is investigated in terms of pressure environment. Due to the unsteady nature of the problem, unsteady discrete-adjoint method is used to decrease the pressure values over the rocket by optimizing the shape of the FD. Shape optimization process are carried using open-source SU2 CFD solver due to its unsteady adjoint support.