基于涡旋强度亚格子应力模型的湍流有旋流动大涡模拟

为了改进大涡模拟方法预测湍流有旋流动的能力，将一种基于涡旋强度构建的亚格子涡粘模型应用于悉尼旋流燃烧器的冷态场大涡模拟中.选取高雷诺数低旋流数和低雷诺数高旋流数两种工况，验证该模型在强剪切且有旋流场大涡模拟中的表现，并与动态Smagorinsky（DSM）模型模拟结果以及实验结果进行比较.模拟结果表明,基于涡旋强度模型（SSM）的大涡模拟结果能够合理预测钝体回流区、二次回流区以及中心射流进动等重要特征，同时速度统计矩结果总体好于DSM模型结果.但在旋流剪切层处二阶矩预测较高，说明SSM模型在剪切层处可能耗散较大，需要改进.
Abstract：To enhance the ability of large eddy simulation (LES) to predict turbulent swirling flow, a subgrid eddy viscosity model based on the swirling-strength was applied to the LES of the non-reactive flow of the Sydney swirl burner. Two operation conditions， high Reynolds number with low swirl number and low Reynolds number with high swirl number, were selected to validate the performance of the proposed model in the strong shear layer and swirling flow, and the model simulation results were compared with the dynamic Smagorinsky model (DSM) and experimental results. The simulation results show that the LES results based on the swirling-strength model (SSM) can reasonably predict the important characteristics of the recirculation zone and precession motion of the central jet, which indicates the SSM model results of statistical moment are better than the DSM model results. However, the prediction of the RMS values at the shear layer of swirling flow is higher than experimental data, which indicates that the kinetic energy dissipation of SSM model may be over predicted in the shear layer, and that the SSM model needs to be improved in future.