TJ539 : 3d development of numerical simulation of laminar fluid flow using Immersed Boundary Lattice Boltzmann method
Thesis > Central Library of Shahrood University > Mechanical Engineering > MSc > 2018
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Abstarct: The fluid behavior has a significant role in daily life as well as industrial applications. When construction is costly or difficult, the importance of simulation will be enhanced. Simulation suffers from some shortcomings. The feasibility of the construction, high computational cost, and restriction in RAM are some of the aforementioned shortcomings. Thus, methods in the simulation which are able to act in appropriate computational costs and systematic restrictions moreover, are capable of presenting results with suitable accuracy. One of these methods is immersed boundary-lattice Boltzmann method. The method with combining the lattice Boltzmann method with immersed boundary method is able to simulate particulate flow with worthy accuracy. In flows when the number of particles is high, the methods such as the one mentioned above, show better results. The model uses to sets of computational nodes which are Lagrangian and Eulerian. The Lagrangian nodes are the one which are on the considered particle and Eulerian nodes are the lattice nodes. The immersed boundary method using the velocity and force differences will change the velocity and pressure on the Lagrangian nodes, thus fluid is able to recognize the particle movement. Furthermore, the existed boundary condition or the no-slip condition will be satisfied. In the current study, the flow in a cavity and over a fixed sphere is assessed with developing 2D code to 3D. the particule flows analysis is applicable With developing the 2D Ib-Lbm code to 3D. To develope the code for 3D problems the boundary conditions and divergence must be overcome. Boundary conditions in 3D lbm are considerably more complex than 2D situation as well as their imposition. Imposing the moving fluid in 3d condition due the flows more freedom is other aspect of complexity in terms of 3D simulation. In the 3D state the relations for boundary condition are more complex which are derived and noted. In the cavity variations of velocity at the centerline is shown to validate the simulation. Then, a stationary is subjected to a Newtonian fluid under the laminar flow condition. To validate this part, the Strouhal number and drag coefficient around the sphere is used. Also, the effects of enhancing the Reynolds number on the lift and drag coefficient is investigated. The variations of streamline and vortices are also displayed. Flow passed the fixed sphere at the steady and unsteady situation to the Reynolds number equal to 300 is studied. At Re=300 due to transient fluid condition and mobile vortices, lift and drag coefficient will have a transient behavior also they will start repetition at a certain time period.
Keywords:
#lattice Boltzmann method #immersed boundary method #3D Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
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