利用喷管引射和旋翼下洗的红外抑制器特性研究

在波瓣引射器一次引射掺混后,提出利用旋翼下洗气流对弯曲混合管排气进行二次强迫混合的红外抑制器结构,并对该红外抑制器进行了有关流动混合特性的实验和数值研究,获得了主流和引射气流、下洗气流相互混合过程中,混合管内部及抑制器出口处的温度场和压力场等相关信息,以及表征引射-混合系统总体性能的引射系数等参数。结果表明:引入下洗气流可以改善出口分布的不均匀性,经过波瓣喷管引射器泵吸周围空气掺混冷却和利用旋翼下洗气流进行二次冷却,可以有效使排气温度降低50%。

Flow and Mixing Characteristics Inside Infrared Suppressor Utilizing Nozzle Ejection and Rotor Downwash

A new configuration of infrared suppressor utilizing nozzle ejector and rotor downwash is presented,relevant experimental and computational study is conducted on the mixing characteristics inside the new infrared suppressor.The related information of both temperature field and pressure field located at the curved nozzle and the model exit are achieved,by mixing the main stream with the rotor downwash;meanwhile the pumping coefficient reflecting the integrated characteristics of mixer-ejector system is also obtained.Results show that the downwash flow can improve the uniformity of the exit temperature contours,and exhaust temperature is decreased about 50% by mixing with the second flow,as well as the rotor downwash.