气膜孔排布对排气系统中心锥冷却和红外辐射特性的影响

Effects of film hole arrangement on central-cone cooling and infrared radiation characteristics of exhaust system

运用计算流体力学/红外辐射（CFD/IR）的数值模拟方法,以涡扇发动机排气系统为原型,对中心锥表面气膜冷却方案进行了数值研究,并揭示了中心锥冷却对红外辐射特征的作用效果.研究表明：气膜冷却中心锥可有效降低中心锥表面的温度,抑制排气系统在0°~15°范围内的红外辐射.在所研究的诸多方案中,与无冷却的涡扇排气系统相比,中心锥表面温度可以降低282K,0°方向上可降低总体红外辐射约57%.

The axisymmetric convergent-expansion nozzle exhaust system of a certain turbofan engine was taken as a prototype wherein the film cooling schemes on the central- cone surface were numerically investigated by CFD/IR methods. The cooling schemes were compared and the cooling action of central-cone surface on the infrared radiation characteris- tics was revealed. The results show that the film cooling on the central-cone surface could effec- tively decrease the surface temperature, and suppress the infrared radiation intensity between 0 degree and 15 degree viewed from backward direction. The best cooling scheme achieved about 282 K decrease on the central-cone surface as well as 57 % relative decrease of infrared radiation intensity on 0 degree direction by comparing with the prototype exhaust system.