多喷管火箭上升段羽流流场及其底部热环境

A nine-nozzle configuration rocket was established for the heating protection problem of the multi-nozzle rocket caused by the plume flow field structure and base heating in the ascent phase. Compared with the wind tunnel test data，the reliability of the numerical method was verified，and the numerical simulations were carried out for the plume flow field and the base heating environment at different altitudes. The results indicated that collisions occurred between gas jets， and there existed circulation vortices，gas backflow and back splash at different altitudes. The higher altitude indicated the greater expansion angle of the jet. At low flight altitudes，the base heating was mainly affected by radiation heating，and as the altitude increased，the effect of convection heating was enhanced. The peak of base heating flow density occurred within the range of 30 to 40 km，with a maximum convective heating flow density of 318.16 kW/m²，a maximum radiant heating flow density of 315.38 kW/m² and a maximum total heating flow density of 570.31 kW/m². The temperature gradient of rocket base was the main influence on convection heating，while radiation heating was mainly influenced by the radiation intensity，distance and area of the radiation micro-element.