بررسي اندر كنش جريان سطح آزاد با جسم جامد لاستيك به روش SPH

چكيده انگليسي :

Numerical simulation of interaction of free surface flows with an elastic solid using SPH Mohsen Lahooti m lahooti@me iut ac ir December 12 2008 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Dr A Pishevar Dr M S SaidiAbstractThe increasing accuracy requirements in many of today s simulation tasks in science and engineering more andmore often entail the need to take into account more than one physical effect Among these multiphysics problemsare fluid structure interactions FSI i e interactions of some moving or deformable elastic structure with aninternal or surrounding fluid flow Before simulating a FSI problem some decisions must be taken about the method of integration of governingequations in each phase and the strategy for considering the effect of one phase on the other one at the separatinginterfaces Most of algorithms and methods that have been developed so far to simulate the FSI problems are meshbased for example Nonlinear formulation of Finite Element Method FEM Arbitrary Lagrangian Eulerian Method ALE and potential based and Immersed methods Recently a new generation of meshfree numerical methods hasbeen emerged to tackle problems with moving boundaries One of these meshfree methods is Smoothed ParticleHydrodynamics SPH Due to Lagrangian view point and truly meshless formulation of SPH method it can offer analternative choice to simulate problems encountered free surfaces interfaces violent and large deformations There are also two main strategies for dealing with the interfaces in FSI problems i e segregated and coupledstrategy The first approach is the easiest one In segregated strategy the governing equations are integratedsequentially in each media and therefore the effects of each phase on the other one have a lag through timestepping On the other hand in coupled approach the governing equation are integrated simultaneously and theproblem domain is considered as a unified system In this study the SPH method with coupled strategy are chosen to integrate governing equations for the FSIproblems An algorithm is developed which is capable of dealing with large deformations and high density ratios Inthis study fluid is considered to behave as a Newtonian viscous fluid and solid is supposed to be an elastic body withlarge deformation To validate the algorithm first three problems with the presence of only a single phase solid or fluid areconsidered These include the free deformation of a fluid patch in a void the dam breaking test case and the freevibration of a cantilever beam Numerical results show that the algorithm can accurately predict single phaseproblems with violent deformation at the surfaces Then the algorithm is applied to two FSI problems As the firstFSI test case an elastic bed lid driven cavity is considered and its results are compared with the results obtained by aFEM approach A parametric study of solid and fluid properties is performed to investigate the behaviors ofproposed algorithm in different density ratios and deformation rates Finally the last test case is devoted to theproblem of an oscillating cantilever beam in a confined and unconfined fluid Conclusion

لاهوتي، محسن

بررسي اندر كنش جريان سطح آزاد با جسم جامد لاستيك به روش SPH

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