The Effect of Fluidic Pintle Nozzle on the Ablative Features

Fluidic Pintle Nozzle (FPN) combines mechanical and fluidic schemes to inject secondary flow at the head of the pintle to change the mainstream gas profile. As a means of mechanical combined with fluidic regulation, this method has not completed systematic research since it was proposed, and the current research is still in the basic theoretical stage, with insufficient research on its basic laws, flow mechanism, influencing factors, ablative protection and so on. This paper focuses on the influence of injecting secondary flow at the head of the pintle on the ablation of the fluidic pintle nozzle of the solid rocket motor, the surface chemical reaction model under fluid–solid coupling was established, and fluent commercial software was used for numerical calculation. The basic law and influencing factors of the ablative rate with a different opening, injection position, and secondary flow temperature were studied on the ablation rate of the nozzle were studied. The results show that the ablation rate of the nozzle is significantly different under the different openings. A low-temperature jet can effectively reduce the temperature of the pintle, reduce the ablation rate of the pintle, and has a significant protective effect on the pintle downstream of the injection hole.