Coupled Flow-Thermal Analysis of a Rocket Nozzle with Charring Ablative Thermal Protection System

Abstract: This study investigates conjugate heat transfer analysis of a rocket nozzle featuring a charring ablative thermal protection system. The study is carried out by weakly coupling a commercial computational fluid dynamics (CFD) flow solver Fluent with an in-house material thermal response solver. The coupling of the two solvers is carried out by exchanging the boundary conditions at the fluid-solid interface using a non-iterative approach. Validation of the numerical framework is performed. A blowing correlation is used to model the pyrolysis gas behavior at the interface. Results highlight a significant surface heating and ablation particularly at the nozzle throat.