Investigation on flow field and operating characteristics of pintle-controlled solid rocket motor during dynamic regulation process

In order to study the flow field and operating characteristics during the dynamic regulation of pintle controlled solid rocket motor, an integrated simulation model considering the propellant combustion flow, pintle dynamic regulation and exhaust plume flow was established. The combustion chamber pressure, the response law of thrust and the variation law of plume flow structure were analyzed. In order to further reveal the mechanism of dynamic characteristics, a regulated zero-dimensional internal ballistic model with variable equivalent throat area is developed. The effect of pintle motion speed on the dynamic response characteristics of the motor was analyzed. The results show that: There is a significant delay in the response of the combustion chamber pressure during the pintle motion, and the flow structure of the supersonic exhaust plume changes accordingly. The flow state of the plume is determined by both the combustion chamber pressure and the expansion ratio. Since the response of the flow field lags behind the structural changes of the motor brought about by the pintle motion, the response pattern of the plume surge structure does not overlap in the positive and negative strokes of the pintle. As the velocity of the pintle increases, the response time of the combustion chamber pressure becomes shorter and tends to a constant value, while the thrust overshoot gradually increases.