直升机多路分流排气引射红外抑制系统气动特性计算

针对直升机用单级引射、三路分流排气红外抑制系统进行了内部流场的三维数值模拟,在给定的模拟条件下,得到如下结论:①该红外抑制系统引射能力较强,三个支路引射混合管的引射流量比存在较大差异,总压恢复系数相差甚微;②分流喷管各支路通道喷口主流出口速度和压力基本一致,对各支路引射混合管引射能力影响最大的因素是次流流道的通畅程度;③三个支路引射混合管内主流核心速度和混合管出口温度衰减程度与其引射次流流量大小相关.

Numerical research on aerodynamic characteristics inside single-stage ejection and multi-nozzles infrared system of helicopter

Three-dimensional numerical simulation was carried out to investigate the internal aerodynamic characteristics insides the single-stage ejection and multi-nozzles infrared radiation suppressor being used in the army helicopter. Conclusions can be drawn as follows according to the simulation conditions: (1) this kind of infrared radiation suppressor has an impressive ability to pump secondary flow, the pumping ratios for three individual mixing duct are different obviously and the total pressure recovery coefficients are almost the same; (2) the primary flow velocities and pressures at multi-nozzles exit are the same, the important factor affecting the pumping ratio of the individual mixing duct is the secondary flow smooth level; (3) the decay of the primary flow core velocity and temperature is relative to pumping ratio for three individual mixing duct.