Numerical Analysis of Gas-Core Dynamics and Atomization in a Kerosene Swirl Injector

The atomization performance of swirl injectors plays a crucial role in the combustion efficiency and stability of liquid rocket engines. This study presents a numerical investigation into the internal flow dynamics and atomization characteristics of a kerosene swirl injector using the Volume of Fluid (VOF) method. The research captures gas-core evolution, liquid film thickness variations, and spray cone angle trends, validated against theoretical predictions. Results indicate that tangential inlet jets generate helical flows, leading to transient liquid film instabilities and vortex-induced recirculation near the injector exit. The gas core undergoes progressive compression, stabilizing over time, while liquid film thickness increases proportionally with mass flow rate. Comparative analysis shows that simulated results closely align with theoretical expectations, with errors of 2.6% in mass flow rate, 6.8% in liquid film thickness, and 12.0% in spray cone angle. The study highlights key mechanisms governing injector atomization and provides insights for optimizing rocket engine injection system designs. Future research should refine computational accuracy by enhancing mesh resolution, improving interface-tracking algorithms, and incorporating surface roughness effects.