塞锥形状和偏转角对轴对称塞式喷管气动性能的影响

塞式喷管是1种具有质量轻、红外隐身效果好等优点的典型喷管.为分析矢量偏转角和塞锥的几何参数对涡扇发动机轴对称塞式矢量喷管排气系统气动特性的影响,采用CFD方法进行了数值模拟研究.结果表明:尾喷流随喷管偏转而有效偏转,推力系数随矢量偏转而减小,在高空状态下较为严重.在地面状态下偏转20°时的推力系数较无矢量偏转时减小了1.2％,在高空状态下偏转20°时的推力系数减小了2.5％;塞锥前体的导圆半径变化没有使气流分离,对气动性能影响不大;塞锥后体长度增加使喷管内部压力提升,塞锥尾缘低压区缩小.

Effects of plug shape and vectoring angle on aerodynamic performance of axisymmetric plug nozzle

Plug nozzle is regarded as a typical exhaust nozzle with lighter weight and lower infrared radiation. In order to analysis the effects of vectoring deflection angle and plug geometric parameters on the aerodynamic performance of the plug nozzle, numerical simulations on the flow fields were performed by CFD method. Results show that jet effectively deflect with nozzle deflection, the thrust coefficient decreases as the increase of vectoring deflection angle,especially under high altitude. The thrust coefficients under vectoring deflection angle of 20 degree decrease relatively about 1.2% and 2.5% for the ground status and high altitude status. Radius change at the plug front body does not make the flow separate and have little effect on the aerodynamic performance. Increase of the plug rear body length increases the pressure inside the nozzle and shortens the lower pressure zone near the plug trailing edge.