通过求解三维定常雷诺时均方程,采用剪切应力输运(SST)湍流模型,在亚声速范围内,分别对融合体前体-三角翼组合体和旋成体前体-三角翼组合体流场中翼涡破裂现象进行了数值模拟。模拟结果显示:与旋成体前体相比,在中、大迎角时,融合体前体的分离涡,涡量集中、强度高,进入机翼上方流场后,能够与翼涡密切耦合,彻底地改变翼涡强度的分布状态,显著地延迟翼涡破裂。在此基础上,对融合体前体延迟翼涡破裂的机理进行了深入探讨。通过对模拟结果的对比分析,可得出下述结论:(1)机身前体横截面形状对翼涡强度的分布状态有着重大影响;(2)翼涡强度的分布状态对翼涡破裂位置有着重大影响,保持翼涡强度递增,有利于形成轴向顺压梯度,是延迟翼涡破裂的一个重要措施。
3D steady Reynolds-averaged Navier-Stokes equations together with a shear stress transport (SST) turbulence model are applied for the numerical simulation of vortex burst over a chine forebody/delta wing configuration and a tangent-ogive forebody/delta wing configuration respectively in the subsonic case. The results show that compared with the tangent-ogive forebody, at moderate and high angles of attack, the chine forebody vortex contains a higher concentration of vorticity which is also very strong. As it enters the wing flow field, it can couple closely with the wing vortex, thus completely changing the wing vortex strength distribution and remarkably delaying the wing vortex burst. On the basis of the above, the mechanism is investigated by which the chine forebody can delay delta wing vortex burst. Through analyzing and comparing the simulation results, it can be concluded that: (1) The forebody cross-sectional shape has a significant influence on the distribution of the wing vortex strength; (2) The distribution of the wing vortex strength has a significant effect on the wing vortex burst location. Trying to keep the vortex strength gradually on the rise so as to create a favorable pressure gradient along the axis of the vortex is therefore an important way to delay the wing vortex burst.
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