波瓣喷管红外抑制系统的实验研究

在电加热风洞上对不同的引射流量比和遮挡间距进行了混合流出口的总温分布和混合管及遮挡套壁面温度分布的测试。结果表明：冷气掺混具有降低排气温度和混合管壁面温度的双重作用，其降温效果在大引射流量比下更为显著；当遮挡间距大于２０ｍｍ时，遮挡隔热可以使遮挡套壁温接近于环境温度。同时，在燃烧设备上对一典型结构的波瓣喷管红外抑制系统进行了尾焰辐射亮度和总体辐射强度测试，证实其可显著地降低红外辐射。

AN EXPERIMENTAL STUDY ON A LOBED NOZZLE OF AN INFRARED SUPPRESSION SYSTEM

An experimental study on the lobed nozzle of an infrared suppression system has been carried out at the low-speed wind tunnel with the electrical heater.The total temperature distribution at mixing flow exit and the temperature distribution on mixing duct and sheltering sheath were measured under different mass flow ratios of secondary stream to primary stream and differeat distances of the mixing duct from the sheltering sheath.The results show that ambient air mixing plays a dual role for reducing the exhaust temperature and mixing duct temperature.Sheltering from the hot wall makes the sheltering sheath temperature close to ambient temperature in case of the sheltering distance greater than 20 mm.Simultaneously,the plume irradiance and total radiation intensity for a typical lobed nozzle of an infrared suppression system were also measured to evaluate the infrared suppression effect.The data indicate that it does significantly reduce infrared radiation signature.