Influence of the deflector surface configuration on thermal environment during rocket launching

Abstract

During rocket launches, high-temperature and high-pressure exhaust gases from rocket engines impose substantial thermal and mechanical loads on launch platforms. To address this, deflector systems are implemented to effectively guide the exhaust gas deflection and discharge. Numerical simulations of turbulent combustion were conducted based on the hybrid RANS/LES turbulence model combined with finite-rate chemical kinetics, while experimental data validation was conducted to verify the model’s accuracy. Furthermore, a comparative analysis was carried out to investigate the effects of concave, normal, and convex impingement surfaces on the gas jet flow field characteristics. The findings reveal that the concave impingement surface demonstrated the most pronounced effectiveness in reducing thermal loads on the deflector surface. Specifically, compared with the convex configuration, the concave surface exhibited a 7.9% reduction in peak temperature and a 24.3% improvement in flow guidance efficiency. This enhancement is attributed to the concave surface’s expanded reflection area, which effectively suppresses exhaust gas recirculation within the deflector zone, thereby reducing thermal loads on both the export surface and trench zone. However, it should be noted that the concave configuration may induce multiple gas jet interactions near the impingement region, leading to localized concentration of both mechanical stresses and thermal fluxes, which could potentially compromise the deflector system’s longevity and operational reliability. These insights offer critical theoretical foundations for deflector system optimization.