Pω增强型k-ω湍流模型在三角翼旋涡流动的应用

在三角翼旋涡绕流数值模拟中,标准 Wilcox k-ω湍流模型生成项未考虑旋度的影响而导致预测的旋涡强度较弱。通过引入探测因子区分剪切层和涡核,在旋涡流动的高旋度区域增加ω方程生成项的方法,基于结构化网格上的 RANS 求解器,加入了 Pω增强型 k-ω湍流模型,对绕尖前缘三角翼亚声速和跨声速旋涡流场进行了数值模拟。计算结果与 NASA 的 NTF 风洞和 DLR 的 DNW-TWG 风洞试验数据进行了对比分析,结果表明：不论在亚声速还是跨声速自由来流条件下,Pω增强型 k-ω湍流模型计算的压力分布、涡破裂位置均与试验数据吻合良好,准确地预测出了三角翼上翼面的主涡、二次涡结构,特别是跨声速条件下激波干扰导致的涡破裂的临界迎角及涡破裂位置,表明 Pω增强型 k-ω湍流模型在绕三角翼旋涡流动数值模拟中具有良好的适用性。

Application of k-ω with Pω enhancer turbulence model to delta wing vortical flows

The production of k-ω within standard Wilcox k-ω turbulence model is dependent on the mean strain-rate of the flow and does not take the rotation rate into account,resulting in the prediction of a weak vortex which can’t be sustained and diffuses quickly.A suitable sensor is defined to distinguish between shear layers and vortex cores,to increase the production of the dissipation rate (ω)within regions of highly rotational flow.k-ω with Pω enhancer turbulence model is applied to RANS solver for structured grid.Subsonic and transonic flows around a 65 o swept leading edge delta wing are simulated numerically.The computational results are compared with detailed experimental data obtained from a series of wind tunnel tests in the NTF at NASA and DNW-TWG at DLR.The comparisons show that the k-ω with Pω enhancer turbulence model produces better results when it comes to capturing the vortex core,the critical angle of attack and the position of vortex breakdown at subsonic and transonic flows,thus is suitable for simulating the vortical flow around delta wing.