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采用一维无粘理论对扩张喷管的流动和性能进行了计算,研究了壁面散热量和散热规律对喷管流动、出口气流参数和性能参数的影响。结果表明:壁面散热会导致喷管沿程静压、静温和总温减小、出口马赫数和总压增大,并且随散热量增大,喷管的工作状态可依次经历欠膨胀状态、临界状态和过膨胀状态,但是喷管的推力系数逐渐减小,性能下降;壁面散热规律对喷管性能有很大影响,入口附近散热量较大出口附近散热量较小时,喷管的性能下降最大。从研究结果可以看出,壁面散热可以调节喷管的欠膨胀度,使喷管从欠膨胀状态趋于过膨胀状态,采用侧重于后半部分散热的规律可以取得良好的调节效果。
The one-dimensional non-stick theory is used to calculate the flow and performance of the expansion nozzle. The effects of wall heat dissipation and heat dissipation on nozzle flow, outlet airflow parameters and performance parameters are studied. The results show that the wall heat dissipation can cause the nozzle static pressure, the static temperature and the total temperature to decrease, the Mach number and the total pressure at the outlet to increase, and as the heat dissipation increases, the working state of the nozzle can successively experience the under-expansion state, State and over-swollen state, but the thrust coefficient of the nozzle is gradually decreased and the performance is decreased. The wall heat dissipation has a great influence on the performance of the nozzle. When the heat dissipation is large near the inlet and the heat dissipation is small near the outlet, the performance of the nozzle decreases most . From the research results, it can be seen that wall cooling can adjust the degree of under-expansion of the nozzle so that the nozzle tends to be over-expanded from the under-expanded state, and good regulation effect can be obtained by using the law focusing on the heat dissipation of the second half.