直升机发动机舱通风冷却优化设计

Optimal Design on the Ventilation and Cooling Capacity of the Helicopter Nacelle

针对AC313A民用直升机发动机舱超温问题,提出了两种不同结构的排气引射管,通过数值仿真手段对比分析排气引射能力,以及其对发动机舱通风冷却的影响。结果显示,通过改变排气引射管的结构,可以改变引射比,从而改变发动机舱通风冷却情况,改变发动机舱内温度分布;收敛型喷管和波瓣喷管均能提高引射率,降低发动机舱温度分布,但收敛型喷管总压损失较大。研究结果为后续提升发动机舱通风冷却能力提供了优化方向。

In order to solve the over temperature problem of the nacelle of a civil helicopter,two kinds of exhaust ejector tubes with different structures were proposed.The exhaust ejector capability and its effect on the ventilation and cooling of the nacelle were analyzed by numerical simulation.The results showed that by changing the structure of the exhaust ejector tube,the ejector ratio could be changed,so as to change the ventilation and cooling of the nacelle and change the temperature distribution in the nacelle.Both convergent nozzle and lobe nozzle could increase the ejection rate and reduce the temperature distribution of the nacelle,but the total pressure loss of convergent nozzle was greater.It provided the optimization direction for the subsequent improvement of the ventilation and cooling capacity of the nacelle.