Numerical solutions of nanofluids in cavity flow with various aspect ratios

Nanofluids and changes of their behaviour with the influence of force and heat are a frequently discussed issue in recent years. Despite the studies are experimental in general, the mathematical approach to this type of problems has also started to be discussed among scientists. The aim of this thesis is to investigate the lid driven and bouyancy driven problem for nanofluids with different structures in the closed cavity using numerical method. It is anticipated that this investigation will reveal new results for the motion of nanofluids through viscosity or convection and characterize their behavior. The elliptical type of partial differential equations which are steady state are considered. The finite difference method was used for the discretization of the continuity, velocity, momentum and energy equations, and the SOR method was used for the numerical solution of the discretized equations. Firstly, the results for the newtonian fluid for lid driven problem were taken and these results were compared with the results obtained by Tosoka, N., Kakuda, N. (1994), then the results obtained for the Newtonian fluids in the buoyancy driven problem were taken and the results were compared with the results obtained by De Vahl Davis (1983). It seemed that the results that obtained are fully compatible both in terms of quality and quantity with literature. Thus, for nanofluids with different structures, in case of different aspect ratios in the lid driven flow and different geometries of obstacles in the cavity, results with different values of Reynolds number were obtained and shown graphically. For buoyancy driven problem, graphical results were obtained at different values of Rayleigh number for nanofluids with different structures under double glazing conditions and Nusselt numbers were examined. The Matlab software is used to program the numerical algorithm. Alumina, copper and boron were used as nanoparticle, and water was taken as the base fluid. The results that obtained, the changes in the motion of nanofluids with different structures, by virtue of viscosity or convection, were interpreted by comparing them with newtonian fluids. Finite difference discretization and SOR method which are used for numerical solution, provides programming convenience moreover it has also been concluded that it gives fast, consistent and reliable results.