部件冷却对二元俯仰矢量排气系统红外特征抑制实验

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）。 

Experiment on infrared characteristics suppression by component cooling of two dimensional convergent divergent vectoring nozzle exhaust system

Experiment was conducted to study the distribution of wall temperature and infrared radiation characteristics on two-dimensional convergent-divergent (2D-CD) vectoring nozzle exhaust system with cone film cooling and nozzle impingement-film cooling,in three geometric deflection states,namely deflection of 0°,10°,20°,and the results were compared with no-cooling state.The experimental results showed that film holes with pre dense and after thinning arrangement form can effectively reduce the hot side temperature region size.For cone cooling state,under the conditions of density flow ratio of 0.8,cooling efficiency reached 45 ％-63％,the infrared radiation intensity of exhaust system decreased by 20％,in the tail direction ± 10°,but due to the cooling air flow injection,the temperature of heat shield wall and nozzle wall increased,and infrared radiation intensity increased by 15％,in 30° detection direction.In nozzle cooling state,convergent section (density flow ratio of 0.25) cooling efficiency reached 19％-33％,the expansion section (density flow ratio of 0.65) cooling efficiency reached 75.5％-83.5％,the side wall sections (density flow ratio of 0.65) cooling efficiency reached 78％-90％,infrared radiation intensity decreased by more than 30％,in the tail direction 15°-75°,the maximum decrease reached 80％ (geometric deflection angle of 20°,detection direction of 30°).