单边膨胀喷管几何参数对内特性和流场的影响  

Effects of Geometric Parameters on Internal Performance and Flowfield of Single Expansion Ramp Nozzles

作　　者：谭杰[1] 金捷[1] 

机构地区：[1]北京航空航天大学能源与动力工程学院/航空发动机数值仿真中心,北京100191

出　　处：《推进技术》2013年第2期152-160,共9页Journal of Propulsion Technology

摘　　要：采用三维数值模拟方法研究了单边膨胀喷管(SERN)主要几何参数对其内特性和流场的影响,计算结果表明:侧壁的延伸对SERN的轴向推力系数Cfa是有益的,但过大的侧壁浸湿面积会产生大的摩擦损失从而使推力性能下降;其中部分封闭侧壁的性能要略微高于全封闭式侧壁,而相比于短侧壁,其Cfa的优势在2%左右;此外,侧壁的延伸可以有效降低设计点的推力矢量角δp;长的曲壁模型拥有高Cfa的同时其δp处于较低的水平,在设计点条件下,最高Cfa可达0.983,这与传统的轴对称喷管和二元收扩喷管相差不大;在高落压比条件下,大的喷管喉道宽高比可以有效降低气流展向膨胀损失从而具有高的Cfa和低的δp,而且其优势随NPR的增大而增加。3-D Navier-Stokes calculations were carried out to investigate the effects of geometric parameters on internal performance and flowfield of single expansion ramp nozzles（SERNs）.The results show that,in general,the nozzle sidewall extension has a beneficial effect on nozzle thrust.However,excessive large wetted surface area of sidewall results in great friction loss,which is already prevailing over the pressure gain by sidewall extension.The partial sidewalls perform slightly better than full sidewalls,and the axial thrust ratio Cfa is 2% larger than short sidewalls.Moreover,the extended sidewall reduces the pitch thrust vector angle δp effectively at the design point.The long curved ramp obtains higher Cfa and smaller δp than the short curved ramp,and the Cfa reaches 0.983 at design point,which is comparable with the conventional axisymmetric and two-dimensional convergent-divergent（2DCD） nozzles.Under the conditions of relatively high nozzle pressure ratios（NPRs）,large throat aspect ratio reduces the spanwise expansion losses effectively,with higher Cfa and smaller δp,and the margin increases with increasing NPR.

关 键 词：单边膨胀喷管 几何参数 内特性 数值模拟 

分 类 号：V231[航空宇航科学与技术—航空宇航推进理论与工程]