| At present, in the application of computational fluid dynamics in engineering,commercial software is more popular than any other ways. In general, commercial CFDsoftware would develop comprehensive and optimized physical models which make it appliedwidely. However, these commercial CFD software have their own weakness such as expensivefees and software maintenance, etc. In addition, using commercial code also means that wedon’t have our own intellectual property, which doesn’t accord with the independentdevelopment innovation of science and technology of our country. OpenFOAM is an effectiveC++object oriented CFD open source libraries which were developed by the British imperialcollege. OpenFOAM constitutes a series of efficient solvers and auxiliary tools. OpenFOAMis based on the finite volume method, which describes and solves the partial differentialequation in a way we are familiar with. In addition, OpenFOAM has some importantcharacters such as openness, fully object-oriented program design and the improvement oflayered framework, which makes users spend less time in developing their own numericalmodels and solvers. In other words, OpenFOAM is a good platform for researchers indeveloping new numerical methods.Projection algorithm can only be used to solve the unsteady flow in its early years. Theprojection algorithm would solve the pressure Possion equation rather than the pressurecorrection equation, which makes it have a higher computing efficiency in parallel computing.Through the untiring effort of researchers from all over the world, the precision and theapplication scope of the projection algorithm have been expanded and improved greatly. Inrecent years, the projection algorithm was widely used in incompressible large eddysimulation and direct numerical simulation. With the development of high performancecomputer, LES and DNS will be the main component of engineering application and scientificresearch in the future. Therefore, it is important to develop CFD solvers based on theprojection method.In this article, a steady turbulent flow solver in OpenFOAM has been modified to atransient turbulent flow solver which could use the LES model. This paper explained thederivation of three kinds of projection algorithm which have been applied to develop CFD solvers in OpenFOAM. In the third chapter, the results calculated by the developed ormodified solvers have been compared with those getting from the original solvers inOpenFOAM in order to verify the availability, solving accuracy and solution efficiency of thedeveloped solvers. In the fourth chapter, the results getting from the commercial CFD softwarehave been compared with that based on OpenFOAM to verify the solving accuracy andsolution efficiency between these two kinds of software.The numerical simulation results have shown that the original steady turbulent flow solverin OpenFOAM have been modified successfully. The modified solvers could be used to solvetransient turbulent flow. The projection algorithm solvers based on OpenFOAM platformhave a good solution precision and efficiency. At present, we could use OpenFOAM to solvelaminar or turbulent cases by a series of algorithms such as SIMPLE algorithm, PISOalgorithm, PIMPLE algorithm and the projection method. The experience of developingsolvers of OpenFOAM makes a good guide in the research and development of OpenFOAM. |
