膨胀边开槽对单边膨胀喷管性能影响的数值研究

为了得到高气动性能和低红外辐射的单边膨胀喷管(SERN)结构,通过CFD/IR数值模拟的方法,研究了单膨胀边开槽率、开槽角度和落压比(NPR)对单边膨胀喷管气动性能和红外辐射特性的影响。研究结果表明:在低落压比下,单膨胀边开槽形成的气动边界改善喷管气动性能;在高落压比下,扩张段内的热排气倒灌入上游的狭槽内,反而降低了喷管气动性能;随开槽角度增加喷管轴向推力系数减小;单膨胀边开槽后喷管红外辐射强度大幅度降低,最高降幅在XOY平面0°方向达90%;随开槽率增加红外辐射强度减小,而开槽角度对喷管红外辐射强度几乎没影响。

Numerical Studies on the Performances of the Single Expansion Ramp Nozzle with Slots on the Ramp

To get the structure of single expansion ramp nozzle(SERN) with good pneumatic performance and small infrared radiation,based on CFD/IR numerical calculations,the effects of slots area ratio,angle of slots and nozzle pressure ratio(NPR) on the aerodynamic and infrared radiation characteristics were revealed for the SERN.The results show that on the condition of low NPR,the slots form the "aerodynamic boundary" to improve the aerodynamic performances of the nozzle.On the condition of high NPR,the hot gas enters the slots to decrease the thrust coefficient.With the slots,the infrared radiation intensity of SERN is largely decreased.The infrared radiation intensity is decreased 90% at 0° on XOY plane.With increase of slots area ratio,the infrared radiation intensity is decreased.The angle of slots has little effect on infrared radiation intensity of SERN.