Study on Combustion Flow-Field of Solid Ducted Rocket with Multiple Gas Nozzles

In order to gain the combustion flow characteristics in the secondary combustor and direct-connect inlet of the solid ducted rocket with multiple gas nozzles, the flow field parameters distribution and combustion performance of the engine under cold flow and combustion conditions were studied by experimental and numerical simulation methods. The results show that under the cold flow state, the supersonic airflow enters the secondary combustor at the high subsonic state after compressing by the oblique shock, which enhances the mixing effect of the secondary combustor. After the fuel-rich gas enters the secondary combustor through the multi-nozzles, the flow field structure becomes extremely complex, and multiple vortex recirculation zones are formed in the head area of the combustor. The distribution of the fuel-rich gas in the secondary combustor is more uniform, and the residence time of the gas and air increases, which enhances the effect of mixing and combustion organization, and the engine has better combustion performance. With the increase of fuel-rich gas flow, the pressure of the secondary combustor rises, and the oblique shock waves of pre-combustion moves forward continuously. The experimental and simulation results accurately capture the forwarding process and stable position of the oblique shock waves, which provides guidance for the subsequent design optimization of the solid ducted rocket.