Differential equation-based specification of turbulence integral length scales for cavity flows
Differential equation-based specification of turbulence integral length scales for cavity flows
复制标题
基于微分方程的空腔流湍流积分长度尺度规范
DOI：
10.1115/1.4035602
复制
发表时间：
2016
影响因子：
1.5
通讯作者：
R. Jefferson
中科院分区：
文献类型：
--
作者：
R. Jefferson
一种新的建模方法已经开发，明确地说明了预期的湍流涡旋长度尺度在空腔区。它使用泊松和汉密尔顿-雅可比微分方程的混合方法。它们用于将湍流长度刻度设置为合理的期望值。对于复杂的边缘密封和叶冠空腔设计，该方法基于局部空腔宽度设定了预期长度尺度，该尺度准确地反映了在这些区域观察到的大规模尾迹流结构。该方法用于生成三种复杂边缘密封几何形状的长度尺度场。发现了良好的收敛性，并观察到区间长度尺度的平滑过渡。该方法与流行的Menter剪切应力输运（MSST） RANS湍流模型相结合，简化为主流流中的标准Menter模型。为了验证该模型的有效性，进行了跨声速深腔仿真。总的来说，在速度和雷诺应力测量方面，泊松-汉密尔顿-雅可比模型比标准Menter RANS模型在数量和质量上都有了显著的改进。在目前的发展中，该方法通过使用泊松方程的长度尺度估计的初始阶段得到了扩展。这从本质上减少了对用户客观性的需求。该方法的一个关键方面是长度比例是由模型而不是建模器自动设置的。值得注意的是，当前的方法很容易在非结构化的并行处理计算框架中实现。
A new modeling approach has been developed that explic-itly accounts for expected turbulent eddy length scales in cavity zones. It uses a hybrid approach with Poisson and Hamilton-Jacobi differential equations. These are used to set turbulent length scales to sensible expected values. For complex rim-seal and shroud cavity designs, the method sets an expected length scale based on local cavity width which accurately accounts for the large-scale wake-like flow structures that have been observed in these zones. The method is used to generate length scale fields for three complex rim-seal geometries. Good convergence prop¬erties are found and a smooth transition of length scale between zones is observed. The approach is integrated with the popular Menter Shear Stress Transport (MSST) RANS turbulence model and reduces to the standard Menter model in the mainstream flow. For validation of the model, a transonic deep cavity simu¬lation is performed. Overall the Poisson-Hamilton-Jacobi model shows significant quantitative and qualitative improvement over the standard Menter RANS model for both velocity and Reynolds stress measurements. In its current development, the approach has been extended through the use of an initial stage of length scale estimation using a Poisson equation. This essentially re-duces the need for user objectivity. A key aspect of the approach is that the length scale is automatically set by the model and not by the modeler. Notably, the current method is readily imple-mentable in an unstructured, parallel processing computational framework.
影响因子：
2.5
作者：
B. Thornber;D. Drikakis
通讯作者：
B. Thornber;D. Drikakis