导弹表面流动分离与后体减阻设计

Drag Reduction Through Controlling Separation on the Missile Afterbodies

采用基于压缩性修正的两方程K-ω-WD+模式数值求解雷诺平均的Navier-Stokes方程组,数值模拟导弹跨、超声速流动(含底部),研究导弹后体多台阶、环向凹槽等典型分离流动的被动减阻措施对阻力缩减的影响。与分离导致阻力增加的传统观点不同,通过分析计算结果发现多台阶能有效降低摩阻及底部阻力;环向凹槽则有利于降低摩擦阻力,底阻减小不明显;组合外形未必能获得较基准外形更多的阻力缩减,欲获得更多的阻力缩减,仍须开展更深入细致的工作。

The transonic and supersonic flows （ including the base region） are predicted by solving Reynolds-averaged Navier-Stokes equations with the compressible correction on two-equation k-w -WD ＋ model. Some passive drag reduction methods, such as the multi-step, toroidal groove and their combinations, are investigated to discover the effect on the skin friction and base drag. For the multi-step afterbody cases, the ratio of length over height k and number of sub-step N are in- vestigated in detail. Differing from the conventional points, separation on the surface can reduce the total drag, especially for the multi-step cases. Toroidal grooves can obtain skin friction reduction but with little base drag reduction. Afterbodies combining the multi-steps and toroidal grooves do not present more drag reduction than their basic configurations.