GPU Parallelization And Application Based On Open Source CFD Software

The molten salt reactor is class of generation IV advanced nuclear energy system using liquid fuel,and it has a good evaluation in terms of sustainability,economy,safety and anti-nuclear proliferation.The molten salt used in the molten salt reactor has a unique heat transfer property and requires numerical heat transfer and computational fluid dynamics to analyze the physical processes.Computational fluid dynamic uses numerical methods to solve the physical problems associated with fluid flow and heat conduction and other related physical problems,requiring large-scale data calculations.With the traditional CPU parallel computing method has not been able to meet the computing requirements,and the rapid development of common graphics computing technology converts many traditional CPU parallel computing method to graphics processor parallel computing method.This thesis studies the GPU parallelization and optimization of computational fluid dynamics software Code_Saturne and applies it to the physical model of molten salt reactor core,including:(1)GPU parallel computing method.This thesis introduces the GPU parallel programming method and takes OpenACC programming model as an example to illustrate the idea of GPU parallel programming.(2)Parallelism analysis.The architecture and program running of the open source computational fluid dynamics software Code_Saturne are introduced in detail.The parallelism of the algorithm in the Code_Saturne source code is analyzed and modified into a parallel computing program on the GPU.In this thesis,the parallel solution on the GPU of the sparse matrix is studied,including preconditioned conjugate gradient method.(3)Accuracy verification of GPU parallel program.The calculation results of the benchmark model based on the cavity-driven flow model show that the calculation result of Code_Saturne before and after GPU parallel acceleration is basically the same,which verifies its accuracy.(4)Optimize performance of GPU parallel program.The speed of parallelism Code_Saturne is analyzed,and the program is optimized by calling the GPU extended function library,adjusting the data storage,and the thread dimension.Combined with the general GPU parallel optimization method,this thesis realizes and optimizes the sparse linear solution module of Code_Saturne,an open source CFD software,which is of reference value for the software development of GPU parallel design of molten salt reactor.