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实验测试了采用中心锥气膜冷却和喷管冲击-气膜冷却的二元俯仰(2D-CD)矢量排气系统,在几何偏转0°,10°,20°三种角度下,壁面温度和红外辐射特征分布,并与未冷却状态进行了对比分析。结果表明:前密后疏的气膜孔排布形式可有效减小热侧面高温区域大小。中心锥冷却时,密流比为0.8条件下壁面冷却效率达45%~63%,排气系统尾向±10°范围内红外辐射强度下降20%;但是由于冷气流注入,导致下游壁面(隔热屏、喷管)温度升高,在30°探测方向上红外辐射强度上升15%。喷管冷却时,收敛段(密流比为0.25)冷却效率达19%~33%,扩张段(密流比为0.65)冷却效率达75.5%~83.5%,侧壁段(密流比为0.65)冷却效率达78%~90%,导致在排气系统尾向15°~75°范围内,红外辐射强度下降30%以上,最大降幅达80%(几何偏转20°,宽边探测面30°探测方向)。
The 2D-CD vector exhaust system with central coning film cooling and nozzle impact-film cooling was tested experimentally. Under the conditions of geometric deflection of 0 °, 10 ° and 20 °, the wall temperature and Infrared radiation characteristics of the distribution, and compared with the uncooled state. The results show that the arrangement of film holes before and after thinning can effectively reduce the size of hot side hot zone. When the center cone is cooled, the wall cooling efficiency reaches 45% -63% at the tight flow ratio of 0.8, and the infrared radiation intensity decreases by 20% within ± 10 ° of the exhaust system. However, due to the injection of cold air, the downstream wall Heat screen, nozzle) temperature rise, 30 ° in the direction of detection of infrared radiation intensity increased by 15%. When the nozzle is cooled, the cooling efficiency reaches 19% -33% in the convergent section (density 0.25) and 75.5% -83.5% in the expanded section (density ratio 0.65) ) Cooling efficiency of 78% to 90%, resulting in the rear end of the exhaust system 15 ° ~ 75 °, the infrared radiation intensity decreased by 30% or more, the maximum decline of 80% (geometry deflection 20 ° wide-angle detection surface 30 ° Detection direction).