9233

8535

كارشناسي ارشد

سازه

اصفهان: دانشگاه صنعتي اصفهان، دانشكده عمران

1393

[ده]،99ص.:مصور، جدول، نمودار

ص. ع. به فارسي و انگليسي

بيژن برومند

احمد رضا پيشه ور

7/8/93

محمد مهدي سعادت پور، مجتبي ازهري

مهندسي عمران

ID8535

3 Dimentional sloshing of free suface fluid Analysis Using Exponential Basis Functions Soheil Bazazzadeh S bazazzadeh@cv iut ac com Date of Submission May 10 2014 Department of Civil Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Dr Bijan Boroomand boromand@cc iut ac ir Advisor Dr Ahmad Reza Pishevar apishe@cc iut ac ir Abstract In this thesis a semi analytical and meshless method is proposed to solve free surface fluid problems Two approaches one based on using the pressure field as the potentaial of the accelerations and anotherbased on using a velocity potential areemplpoyedto solve the equations in 3 dimension In the first approach Navier Stoks equations for incompressible inviscidfluids convert into a pressure Laplace equation which issolved in each time step by a meshless method using residual free basis functions Subsequently fluidparameters such as accelerations velocites and displacements are calculated The boundary conditions of theproblem are defined in terms of acclerations at the walls and the pressure at the free surface The freesurface of the fluid is updated using a Lagrangian approach The solution to the pressure field isapproximatedby as a series of exponential basis functions EBFs These functions are selected in a mannerso that they exactly satisfy the pressure Laplace equation The coefficients of the series are determined bysatisfying the boundary conditions over a selection of boundary points using a collocation scheme through aspecial discrete transformation In the second approach i e using velocity potential for incompressible inviscid fluids Navier Stokesequations convertinto another Laplace equation i e for the potential function The boundary conditions ofthe problem in this case are thus defined in terms of velocities at the walls and the value of the potentialfunction at the free surface Using the meshlessfor this latter problem velocities and thus displacementsaredetermined Since in both aforementioned approaches the solution accuracy of the3D Laplace equation affects theconvergence of the solution over time a new algorithm for the selection of the EBFs is introduced in thisthesis Linear and non linear sloshings in cubic and cylinderical tanks are considered for the validation of theresultswhich are compared with those of other Lagrangian methods Significantly lower computational timeis one of the advantages of the proposed method Key words Exponential basis functions Meshless method Navier Stokes equations Lagrangian freesurface flow Pressure theory Ptential flow theory

بيژن برومند

احمد رضا پيشه ور

محمد مهدي سعادت پور، مجتبي ازهري