Research on Development of Engineering-Application Oriented Subgrid-Scale Estimation Model

面向工程应用的亚网格尺度估算模型开发研究

• 批准号: 12650156
• 负责人: HORIUTI Kiyosi
• 金额: $ 2.11万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2000
• 资助国家: 日本
• 起止时间: 2000 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12650156/
• 关键词: Vortex sheet and tube; Direct numerical simulation; Large-eddy simulation; Homogeneous-isotropic turbulence; Subgrid-scale model; Deconvolution; Estimation model; Aliasing error; Subgrid-scaleモデル; Estimationモデル; ストレイン; 渦度; 回転乱流

The aim of the present study was to develop the subgrid-scale (SGS) estimation model which can be used for application of large-eddy simulation (LES) method in practical engineering flows.In the fiscal year of 2000, we began with the comparison of the performance of several formulations for the SGS estimation model. For this purpose, we generated the Direct numerical simulation (DNS) data for the incompressible homogeneous isotropic turbulence. We carried out direct assessment of the models by measuring the correlation between the exact value for the SGS stress tensor, which was obtained by filtering the DNS data, and the estimate of the stress derived using the SGS models. One of important processes involved with the SGS estimation model is the estimation of the velocities on the grids, the interval of which is half of that for the LES grids. In this process, corrections were incorporated into the velocity fields, which were obtained using the interpolation of the velocity fields on t … More he LES grids, utilizing the dynamics of the Navier-Stokes (N-S) equations, i.e., incorporating an action of the nonlinear terms in the N-S equations. The assessment was carried out by classifying the turbulent structures which are responsible for generation of energy transfer between the grid scale and the SGS. It was found that the method proposed by J.A. Domaradzki et al. (Phys. Fluids 11 (1999), Model 1) yields the overestimate of the contribution of the region in which the strain predominates the vorticity. This drawback of Model 1 was circumvented by applying the projection of the estimated velocity fields onto the solenoidal space using the Helmholtz decomposition (Model 2). Further improvement was achieved by advancing the estimated velocity in time using the N-S equations (Truncated Navier-Stokes (TNS) model, Model 3). We carried out assessment of the three models by applying the models to actual LES calculations of incompressible homogeneous isotropic turbulence which was subjected to rotation, and showed that the performances of Models 2 and 3 is better than those of previous SGS models as well as Model 1.In the fiscal year of 2001, attempts were made to apply the SGS estimation model to practical engineering flows, in which the finite difference method was used as for the numerical method. An important process involved with the application of the finite difference method is the defiltering (deconvolution) of the filtered velocity field. It was shown that this defiltering can be efficiently done using the approximate deconvolution procedure (Horiuti (1999), Stolz et al.(1999)). When the accuracy of the finite difference method was raised, however, it was found that numerical instability arises due to occurrence of the aliasing errors. It was shown that this instability can be eliminated by adding the relaxation term (Stolz et'al.(1999)> to the deconvolution procedure. We carried out LES calculations using the SGS estimation model in conjunction with the approximate deconvolution procedure and addition of the relaxation term, and showed the effectiveness of the proposed model for LES of practical applications. Taking advantage of the higher Reynolds number at which the DNS data was generated in this fiscal year, we conducted the same geometrical assessment of the models as was done in the year 2000, and showed that the accuracy for prediction of the region in which the vorticity predominates the strain obtained using Model 3 was higher than that obtained using Model 2.When the alignment of the eigenvectors for the SGS stress tensor and the grid-scale strain rate tensor was considered, the DNS data showed strong non-alignment of these two eigenvectors, whereas the results obtained using Models 2 and 3 were in good agreement with the DNS data, revealing a limitation of the SGS eddy viscosity model. Less

本研究的目的是发展亚网格尺度（SGS）估算模型，以便在实际工程流动中应用大涡模拟（LES）方法。为此，我们生成了不可压均匀各向同性湍流的直接数值模拟（DNS）数据。通过测量SGS应力张量的精确值（通过过滤DNS数据获得）与使用SGS模型得出的应力估计值之间的相关性，我们对模型进行了直接评估。SGS估计模型的一个重要过程是网格上速度的估计，其间隔是LES网格的一半。在这个过程中，修正被纳入速度场，这是通过使用t上的速度场插值获得的。 ...更多信息 LES网格，利用Navier-Stokes（N-S）方程的动力学，即，在N-S方程中加入非线性项的作用。通过对网格尺度和SGS之间产生能量传递的湍流结构进行分类进行评估。结果表明，J.A. Domaradzki等人（Phys. Fluids 11（1999），模型1）对应变主导涡度的区域的贡献估计过高。模型1的这一缺点通过使用亥姆霍兹分解（模型2）将估计的速度场投影到螺线管空间上来规避。通过使用N-S方程（截断Navier-Stokes（TNS）模型，模型3）在时间上提前估计速度，实现了进一步的改进。通过对旋转不可压均质湍流的大涡模拟计算，对这三种模型进行了评价，结果表明，模型2和模型3的性能优于以往的SGS模型和模型1。2001年，我们尝试将SGS估算模型应用于实际工程流动，其中数值方法采用有限差分法。与有限差分法的应用有关的一个重要过程是对滤波后的速度场进行去滤波（反褶积）。已经表明，可以使用近似反卷积过程有效地进行这种去滤波（Horiuti（1999），Stolz et al.（1999））。然而，当提高有限差分法的精度时，发现由于混叠误差的发生而产生数值不稳定性。结果表明，这种不稳定性可以通过添加弛豫项来消除（Stolz et'al.（1999）>到去卷积程序。我们进行了LES计算使用SGS估计模型结合近似反卷积程序和添加的松弛项，并显示了该模型的有效性LES的实际应用。利用本财政年度生成DNS数据的较高雷诺数，我们对模型进行了与2000年相同的几何评估，结果表明，模型3对涡度主导应变区域的预报精度高于模型2。张量和网格尺度的应变率张量被认为是，DNS数据显示这两个特征向量的强烈不对齐，而使用模型2和3得到的结果与DNS数据吻合良好，揭示了SGS涡动粘度模型的局限性。少

项目成果

堀内潔: "Assessment of Subgrid-scale Models in Dissipative Vortical Structures"Advances in Turbulence VIII, Ed.By C.Dopazo, CIMNE. 519-522 (2000)

Kiyoshi Horiuchi：“耗散涡旋结构中的次网格尺度模型的评估”湍流进展 VIII，C.Dopazo 编，CIMNE 519-522 (2000)。

J.A. Domaradzki & K. Horiuti: "Similarity modeling on an expanded mesh applied to rotating turbulence"Phys. of Fluids. 13. 3510-3512 (2001)

J.A.

K. Horiuti: "Eduction of the vortex sheet structure and analysis of its role for SGS energy transfer, Research Institute for Applied Mechanics, Kyushu University"Reports of RIAM symposium. 12ME-S1. 12-13 (2001)

K. Horiuti：“涡片结构的导出及其对SGS能量转移作用的分析，九州大学应用力学研究所”RIAM研讨会报告。

K. Horiuti: "Alignment of eigenvectors for strain rate and subgrid-scale stress tensors"in "Direct and Large-Eddy Simulation IV," Ed. by B.J. Geurts, R. Friedrich and O. Metais, Kluwer Academic Pub. 67-72 (2001)

K. Horiuti：“直接和大涡模拟 IV”中的“应变率和亚网格尺度应力张量的特征向量对齐”，Ed。

K. Horiuti: "Large-eddy simulation of rotating turbulence, Research Institute for Applied Mechanics, Kyushu University"Reports of RIAM Symposium. 11ME-S3. 88-95 (2000)

K. Horiuti：“旋转湍流的大涡模拟，九州大学应用力学研究所”RIAM研讨会报告。