Numerical Modeling of High Swirl Hybrid Rocket Engines and Comparison with Experiments

This work presents a computational fluid dynamics investigation of hybrid rocket engines featuring high-swirl oxidizer injection. A modeling framework based on Reynolds-averaged Navier–Stokes equations, finite-rate chemistry, and gas–surface interaction models is applied to simulate two experimental configurations: one employing polypropylene, the other paraffin wax as fuel. The simulations are tailored to reproduce the swirl injection characteristics and combustion chamber conditions observed in the experiments. CFD results show good agreement with experimental data, in terms of fuel regression rate, chamber pressure, and global mixture ratio. Overall, the study demonstrates the effectiveness of CFD as a predictive tool for the internal ballistics of hybrid rocket engines.