塞锥后体气膜冷却对轴对称塞式喷管红外辐射和气动性能的影响

运用数值模拟方法,在主流质量流量为130 kg/s、总温为920 K和冷却空气总温为480 K的参数条件下,对比分析了塞锥后体气膜孔排布方式、气膜孔倾角(15°~30°)和气膜冷却空气用量(3%主流质量流量以内)对轴对称塞式喷管红外辐射和气动性能的影响。研究结果表明:塞锥后体的气膜冷却对喷管推力系数的影响十分微弱;对塞锥后体提供1%主流质量流量的冷却空气,喷管红外辐射强度相对无冷却喷管降低50%左右;当冷却空气用量增大至3%时,喷管红外辐射强度下降约60%,总压恢复系数降低较为显著;在相同的冷却空气用量下,小孔排间距的多孔排布方式与大孔排间距相比,具有近乎相同的红外辐射抑制效果和低的总压恢复系数下降幅度;气膜孔倾角从30°减小至15°,对塞锥后体表面温度的降低以及喷管总压恢复系数的改善效果微弱。

Effects of plug rear-body film cooling on infrared radiation and aerodynamic performance of axisymmetric plug nozzle

A series of computations is conducted to investigate the effects of plug rear-body film cooling on the infrared radiation and aerodynamic performance of axisymmetric plug nozzle under the primary flow conditions (primary mass flow rate of 130 kg/s and total temperature of 920 K) as well as the cooling flow temperature of 480 K. The film-hole arrangement, film-holes inclination angle (ranging from 15° to 30°) and cooling air usage (limited in 3% of primary mass flow rate) are chosen as the influencing factors for comparison. The results show that the film cooling on plug rear-body has a very weak influence on the nozzle thrust coefficient. The cooling action on plug rear-body with cooling air usage of one percent of the primary mass flow rate is capable of having approximately 50% infrared radiation intensity reduction relative to the un-cooled nozzle. As the cooling air usage is increased to 3% of the primary mass flow rate, 60% infrared radiation intensity reduction is achieved; however, the total pressure recovery coefficient is decreased more significantly. Given the same cooling air usage, the multi-holes arrangement with small row-pitch seems to be more reasonable because it results in the nearly same infrared radiation suppression but low total pressure recovery coefficient reduction in comparison with the multi-hole arrangement with large row-pitch. The decrease of film-hole inclination angle from 30° to 15° has little influence on reducing surface temperature of the plug rear-body as well as improving total pressure recovery coefficient of the nozzle.