Development of Second-Moment Closure with Comprehensive Testing

综合测试二阶矩闭合的开发

• 批准号: 11650169
• 负责人: SHIMA Nobuyuki
• 金额: $ 1.92万
• 依托单位: Shizuoka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650169/
• 关键词: Turbulence model; Second-moment closure; Low-Reynolds-number model

The purpose of this project is to develop a turbulence model which reproduces a wide range of turbulent flows by testing and refining a low-Reynolds-number second-moment closure without wall-reflection redistribution terms proposed by Shima, the head investigator of the project, in 1997.The second-moment closure (Model 97) has been tested in a variety of turbulent flows of engineering importance. One of the target flows is turbulent swirling flow in a straight pipe. A typical flow in which the tangential velocity profile is of a combined forced-free vortex type and the axial velocity profile has a low velocity region in the core has been predicted with the model 97. The model captures the decay of the swirl velocity and the recovery of the core axial velocity in an inlet region, but in the downstream region, it gives too slow recovery to a non-swirling flow as compared to measurements. When a convection-related redistribution term proposed by the UMIST group is introduced, the turbulence model returns too rapid decay in the inlet region, leading to the agreement with the measured decay in the downstream region. We conclude that the coefficient of the convection-related term should be optimized to obtain the best overall performance.The effects of streamline curvature and wall transpiration in boundary layers and channel flows have also been predicted with the model 97, and it has been found that the model generally reproduces experiments and DNS well.We are now testing the model in annular flow, three-dimentional boundary layers, channel flow with different axes of rotation, unsteady flow and pipe flow oscillating around its axis, aiming at constructing a firm basis for the development of a useful turbulence closure of high generality.

本项目的目的是开发一个湍流模型，通过测试和改进该项目的首席研究员Shima于1997年提出的无壁面反射重分布项的低雷诺数二阶矩闭合，该湍流模型再现了广泛的湍流流动。其中一个目标流动是直管中的湍流旋流。用模型97预测了一个典型的流动，其中切向速度分布是一个组合的强迫自由涡型，轴向速度分布在核心有一个低速区。该模型捕获的旋流速度的衰减和恢复的核心轴向速度在入口区域，但在下游区域，它给出了太慢的恢复到一个非旋流相比，测量。当引入UMIST小组提出的对流相关再分布项时，湍流模型在入口区域返回的衰减过快，导致与下游区域测量的衰减一致。我们的结论是，为了获得最佳的整体性能，对流相关项的系数应进行优化。用模式97还预测了边界层和槽道流中流线曲率和壁面蒸发的影响，发现模式一般都能很好地再现实验和DNS。我们现在正在环形流、三维边界层、不同旋转轴的槽道流、非恒定流和绕其轴振荡的管流，旨在为开发具有高度通用性的实用湍流关闭器奠定坚实的基础。

项目成果

N.Shima: "Prediction of Streamline Curvature Effects on Wall-Bounded Turbulent Flows"International Journal of Heat and Fluid Flow. Vol.21,No.5. 614-619 (2000)

N.Shima：“壁界湍流流线曲率效应的预测”国际热与流体杂志。

N.Shima: "Prediction of Streamline Curvature Effects on Wall-Bounded Turbulent Flows"Proc.1 st Int.Symp.on Turbulence and Shear Flow Phenomena. 221-226 (1999)

N.Shima：“壁界湍流流线曲率效应的预测”Proc.1 st Int.Symp.on 湍流和剪切流现象。