Numerical simulations of thermal environment of the rocket impingement jet with afterburning under different water spray angles

Abstract

To investigate the effect of afterburning and water injection on the thermal environment of the rocket jet flow, three-dimensional hybrid RANS/LES method and a nine-species and ten-step chemical mechanism are used to establish the thermodynamic model of the exhaust plume. The evaporation and condensation of the water flow are simulated by using the Eulerian dispersed phase (EDP) model. The comparison between numerical results and experimental data confirms the validity of this model. Then, the jet flow fields under different water spray angles are calculated. The results show that the afterburning mainly occurs in the mixing layer between the exhaust plume and air. The water spray has an obvious cooling effect on the impingement plate with increasing of the injection angle. Meanwhile, the stability of the jet flow could be affected by large spray angles. The temperature of the impingement plate has a significant dropped after spraying water, by approximately 450 to 750 K. With the increases of the spray angle, the peak temperature in impingement surface gradually decreased and maximum reduction is 17.84%. The rigorous thermal environment of the rocket afterbody is improved after injecting water with a large angle. The results can offer theoretical references for calculation of the jet flow field with water spray, and have vital guiding significance for the water cooling system design.