设计了相同进出口面积、长度条件下的轴对称、矩形以及S弯三种收敛喷管, 在相同气动条件下进行对比试验研究, 测试其水平与垂直平面上的红外辐射强度特征分布, 分析不同探测面上轴对称喷管、矩形喷管与S弯喷管的红外抑制效果随方位角与高度角的变化规律。结果表明, 在水平探测面上, 三者变化规律相同, 红外辐射强度均随方位角增大而减小, S弯喷管红外抑制效果最好; 而在垂直探测面上, S弯喷管红外抑制效果依然最好, 在上方探测面, S弯喷管红外辐射强度随高度角先增大后减小, 在高度角为10°时红外辐射强度最大, 在喷管正后方, 相对轴对称喷管, 矩形喷管与S弯喷管红外抑制效果分别达到35.2%和80.2%;

Three different convergent nozzles(axis symmetrical, rectangular, and S -curved)with the same inlet, outlet areas and lengths, the radiation characteristics in different detecting planes of which were experimentally investigated. The results show that in the horizontal plane, the thermal radiation intensity of three nozzles all decreased with the increase of detecting angle, the S-curved nozzle has the best infrared suppressing characteristics; in the vertical plane, the S-curved nozzle also has the best infrared suppressing characteristics. While being detected from upwards, the intensity of S-curved nozzle increased first then decreased with the increase of angle, and the largest radiation magnitude appeared in the detecting angle 10°. Compared with the axis nozzle, the thermal radiation intensity of rectangular and S-curved nozzles decreased in turn. In the direction of right behind the nozzles, the thermal radiation of rectangular and S-curved nozzles decreased by 33.2% and 80.2% separately, compared with the axis nozzle.