针对核反应堆多物理场耦合模拟中传统程序效率低、精度不足的问题,研究基于开源耦合库preCICE及其适配器OpenFOAM-adapter,构建通用三维核热耦合程序。中子物理模块采用课题组研发的有限体积法中子输运程序,热工水力模块集成三维固体导...针对核反应堆多物理场耦合模拟中传统程序效率低、精度不足的问题,研究基于开源耦合库preCICE及其适配器OpenFOAM-adapter,构建通用三维核热耦合程序。中子物理模块采用课题组研发的有限体积法中子输运程序,热工水力模块集成三维固体导热(laplacianFoam)与流体对流换热模型(buoyantPimpleFoam),通过对preCICE官方OpenFOAM-adapter进行功能拓展,引入OpenFOAM的单元集合(cellSet)机制及其区域管理工具topoSet以界定耦合域;并在配置文件preciceDict中配置volumeCenters字段激活体积耦合模式,实现了中子学与热工水力学求解器间基于非匹配网格的数据映射。选取压水堆(Pressurized Water Reactor,PWR)单棒基准题开展网格无关性分析,对比最近邻映射、最近投影映射、径向基函数映射等数据传递方法。结果表明:程序可精确输出三维功率分布、中子通量密度场及速度场,冷却剂出口平均温度相对误差小于0.1%,包壳最高温度相对误差0.14%,计算结果与文献计算值符合较好。该程序突破传统定制化开发模式,支持异构网格差异化配置与大规模并行计算,可为反应堆安全分析、优化设计等提供参考工具。展开更多
In this study,the dynamic characteristics of microscale floating bubbles near the vertical wall are studied.This occurrence is common in industrial and natural phenomena.Although many studies have been conducted on mi...In this study,the dynamic characteristics of microscale floating bubbles near the vertical wall are studied.This occurrence is common in industrial and natural phenomena.Although many studies have been conducted on microscale bubbles,few studies investigate floating bubbles with very small Reynolds number(Re)near the wall,which is the main research goal of this study.Therefore,this study establishes a model for the ascent of small-scale bubbles near a vertical wall using the interFoam solver in OpenFOAM.This study investigates the influences of diverse viscosity parameters,varying distances from the wall,and different gas flow rates on the terminal velocity,deformation,and motion trajectory of bubbles.The results reveal that as liquid viscosity increases,the Re of bubbles gradually decreases and reaches a minimum of 0.012,which is similar to the Re of micrometer-sized bubbles in water.The characteristics of the wall-induced force in the longitudinal direction are closely related to the changes in liquid viscosity.Under low-viscosity conditions,the induced lift is the principal form of action,whereas under high-viscosity conditions,it is primarily manifested as induced drag.展开更多
We evaluated the performance of OpenFOAMGPT(GPT for generative pretrained transformers),which includes rating multiple large-language models.Some of the present models efficiently manage different computational fluid ...We evaluated the performance of OpenFOAMGPT(GPT for generative pretrained transformers),which includes rating multiple large-language models.Some of the present models efficiently manage different computational fluid dynamics(CFD)tasks,such as adjusting boundary conditions,turbulence models,and solver configurations,although their token cost and stability vary.Locally deployed smaller models such as the QwQ-32B(Q4 KM quantized model)struggled with generating valid solver files for complex processes.Zero-shot prompts commonly fail in simulations with intricate settings,even for large models.Challenges with boundary conditions and solver keywords stress the need for expert supervision,indicating that further development is needed to fully automate specialized CFD simulations.展开更多
文摘针对核反应堆多物理场耦合模拟中传统程序效率低、精度不足的问题,研究基于开源耦合库preCICE及其适配器OpenFOAM-adapter,构建通用三维核热耦合程序。中子物理模块采用课题组研发的有限体积法中子输运程序,热工水力模块集成三维固体导热(laplacianFoam)与流体对流换热模型(buoyantPimpleFoam),通过对preCICE官方OpenFOAM-adapter进行功能拓展,引入OpenFOAM的单元集合(cellSet)机制及其区域管理工具topoSet以界定耦合域;并在配置文件preciceDict中配置volumeCenters字段激活体积耦合模式,实现了中子学与热工水力学求解器间基于非匹配网格的数据映射。选取压水堆(Pressurized Water Reactor,PWR)单棒基准题开展网格无关性分析,对比最近邻映射、最近投影映射、径向基函数映射等数据传递方法。结果表明:程序可精确输出三维功率分布、中子通量密度场及速度场,冷却剂出口平均温度相对误差小于0.1%,包壳最高温度相对误差0.14%,计算结果与文献计算值符合较好。该程序突破传统定制化开发模式,支持异构网格差异化配置与大规模并行计算,可为反应堆安全分析、优化设计等提供参考工具。
基金Supported by the National Natural Science Foundation of China(Grant No.52271319)the Jiangsu Funding Program for Excellent Postdoctoral Talent,and the Postdoctoral Fellowship Program of China Postdoctoral Science Foundation(Grant No.GZC20240618)the Natural Science Foundation of Jiangsu Province of China(BK20231525).
文摘In this study,the dynamic characteristics of microscale floating bubbles near the vertical wall are studied.This occurrence is common in industrial and natural phenomena.Although many studies have been conducted on microscale bubbles,few studies investigate floating bubbles with very small Reynolds number(Re)near the wall,which is the main research goal of this study.Therefore,this study establishes a model for the ascent of small-scale bubbles near a vertical wall using the interFoam solver in OpenFOAM.This study investigates the influences of diverse viscosity parameters,varying distances from the wall,and different gas flow rates on the terminal velocity,deformation,and motion trajectory of bubbles.The results reveal that as liquid viscosity increases,the Re of bubbles gradually decreases and reaches a minimum of 0.012,which is similar to the Re of micrometer-sized bubbles in water.The characteristics of the wall-induced force in the longitudinal direction are closely related to the changes in liquid viscosity.Under low-viscosity conditions,the induced lift is the principal form of action,whereas under high-viscosity conditions,it is primarily manifested as induced drag.
基金supported by the Royal Society(Grant No.RG\R1\251236)the Fundamental Research Funds for the Central Universities of China(Grant No.JKF-2025055317102).
文摘We evaluated the performance of OpenFOAMGPT(GPT for generative pretrained transformers),which includes rating multiple large-language models.Some of the present models efficiently manage different computational fluid dynamics(CFD)tasks,such as adjusting boundary conditions,turbulence models,and solver configurations,although their token cost and stability vary.Locally deployed smaller models such as the QwQ-32B(Q4 KM quantized model)struggled with generating valid solver files for complex processes.Zero-shot prompts commonly fail in simulations with intricate settings,even for large models.Challenges with boundary conditions and solver keywords stress the need for expert supervision,indicating that further development is needed to fully automate specialized CFD simulations.
