参数化流动传热问题的模型降阶方法研究  

Study of Reduced Order Model for Parameterized Flow and Heat Transfer Problems

作　　者：杨迪 段承杰 丁鹏 宋菊青 宋子凡 张纯禹 YANG Di;DUAN Chengjie;DING Peng;SONG Juqing;SONG Zifan;ZHANG Chunyu(Sino-French Institute of Nuclear Engineering and Technology,Sun Yat-sen University,Zhuhai 519082,China;China Nuclear Power Technology Research Institute Co.Ltd.,Shenzhen 518028,China;School of Mechanical Engineering,Dongguan University of Technology,Dongguan 523808,China)

机构地区：[1]中山大学中法核工程与技术学院,广东珠海519082 [2]中广核研究院有限公司,广东深圳518028 [3]东莞理工学院机械学院,广东东莞523808

出　　处：《原子能科学技术》2024年第7期1440-1451,共12页Atomic Energy Science and Technology

基　　金：广东省基础与应用基础研究联合基金(2019A1515110261);广东省教育厅重点领域专项(2022ZDZX2059);东莞市社会发展科技项目(20221800905072)。

摘　　要：高精度的数值模型是构建反应堆堆芯数字孪生的基础,但传统的高分辨率数值模型的计算效率无法满足数字孪生的需求。为显著提高计算效率,综合利用伽辽金投影法和径向基函数插值法构造了参数化流动传热问题的降阶模型。该模型以典型的数值解作为学习样本,通过本征正交分解获得各物理场分布的主模态作为缩减基,然后将控制方程在缩减基张成的空间上进行投影以获得自由度个数显著降低的降阶模型。螺旋十字型燃料冷却剂的测试算例表明,相较于全阶模型,该降阶模型可实现高达3~4个数量级的加速效果,降阶模型的速度场与压力场的相对误差均小于10%。The high-fidelity numerical simulation is the basis for constructing digital twins of reactor cores and other engineering applications.However,the traditional numerical models,such as the finite element model and/or the finite volume model,usually adopt high-resolution grids.The high computation cost makes the traditional high-fidelity models unsuitable for the application of digital twins.Model order reduction is an effective approach to accelerate the simulation whenever a trade-off between computational cost and solution accuracy is a preeminent issue.In this paper,a reduced order model(ROM)which combined both the intrusive and the non-intrusive approaches was constructed for the parameterized thermal-flow problems.The intrusive approach adopted the Galerkin projection method and the non-intrusive approach adopted the radial basis function(RBF)interpolation method.To construct the ROM,some typical numerical solutions were firstly generated by using the finite volume method(also called full-order model,FOM)and then taken as learning samples(also called the snapshots)to generate the reduced bases by the proper orthogonal decomposition(POD)method.After that,the conservation equations of mass,momentum and energy were projected onto the space spanned by the reduced bases.As a result,the number of degrees of freedom is substantially reduced.In terms of the turbulent RANS simulation,the RBF interpolation instead of the Galerkin projection was applied to predict the eddy viscosity in ROM since there exists plenty of turbulent models and projection of those various governing equations would be unfeasible.By this data-driven approach,only the eddy viscosity was treated in the ROM.The parametrization of the Dirichlet boundary conditions was treated by the lift function method,in which a special control function was firstly subtracted from the snapshots of velocity and temperature to yield homogenous field snapshots.After the reduced solution over the inner region was solved by the ROM,the boundary value was patched accor

关 键 词：流动传热 降阶模型 本征正交分解 径向基函数插值 

分 类 号：TL334[核科学技术—核技术及应用]