论文标题
3D高速流的湍流建模，并具有上游信息校正
Turbulence Modeling of 3D High-speed Flows with Upstream-Informed Corrections
论文作者
论文摘要
湍流建模有可能通过成为昂贵，具有挑战性的地面和飞行测试的共同合作伙伴来彻底改变高速车辆的设计。但是，使湍流建模的基本假设是其尺度分辨的对应物的一种吸引人的替代方案，也使其用于实用的高速配置的准确性，尤其是当考虑到完全3D流动时。当前的研究开发了一种方法，以提高双鳍几何形状中复杂的8.3，3D冲击边界层相互作用（SBLI）的湍流建模的性能。具有低雷诺数项的代表性两方程模型被用作测试床。首先，使用涉及Mach 〜11.1零压力梯度边界层的基准测试案例阐明基线模型中的缺陷，并在轴对称压缩角上流动〜6.17。从不同的可能性中，引入了两个系数，以抑制（i）（i）湍流产生和（ii）冲击波下游的湍流长度尺度的非物理过度放大。系数取决于原始模型中已经存在的术语，该术语简化了实施并维持计算成本。系数的值是基于冲击上游的湍流量的分布。这样可以确保修改不会在不必要的情况下（如附着的边界层）等更简单的情况下降低模型预测。显示修饰的作用显示出3D SBLI测试案例的表面压力和壁热通量的显着改善，其中包含在2D情况下未观察到的许多特征，例如3D分离，偏斜的边界层和中心线涡流。提供了有关湍流变量和网格分辨率的流入值的考虑。
Turbulence modeling has the potential to revolutionize high-speed vehicle design by serving as a co-equal partner to costly and challenging ground and flight testing. However, the fundamental assumptions that make turbulence modeling such an appealing alternative to its scale-resolved counterparts also degrade its accuracy for practical high-speed configurations, especially when fully 3D flows are considered. The current investigation develops a methodology to improve the performance of turbulence modeling for a complex Mach 8.3, 3D shock boundary layer interaction (SBLI) in a double fin geometry. A representative two-equation model, with low-Reynolds number terms, is used as a test-bed. Deficiencies in the baseline model are first elucidated using benchmark test cases involving a Mach~11.1 zero pressure gradient boundary layer and a Mach~6.17 flow over an axisymmetric compression corner. From among different possibilities, two coefficients are introduced to inhibit the non-physical over-amplification of (i) turbulence production and (ii) turbulence length-scale downstream of a shock wave. The coefficients rely on terms already present in the original model, which simplifies implementation and maintains computational costs. The values of the coefficients are predicated on the distribution of turbulence quantities upstream of the shock; this ensures that the modifications do not degrade the model predictions in simpler situations such as attached boundary layers, where they are unnecessary. The effects of the modifications are shown to result in significant improvements in surface pressure and wall heat flux for the 3D SBLI test case, which contains numerous features not observed in 2D situations, such as 3D separation, skewed boundary layers and centerline vortices. Considerations on the inflow values of turbulence variables and mesh resolution are provided.
