Litan Kumar Saha

In the present numerical study is devoted to investigate the lid-driven cavity flow with wavy bottom surface. The cavity upper wall is moving with a uniform velocity by unity and the other walls are no-slip. The physical problem is represented mathematically by a set of governing equations and the developed mathematical model is solved by employing Galerkin weighted residual method of finite element formulation. The wide ranges of governing parameters, i. e., the Reynolds number (Re), and the number of undulations (λ) on the flow structures are investigated in detail. The behavior of the force coefficient Cf also has been examined. Streamline plots provide the details of fluid flow. The fluid contained inside a squared cavity is set into motion by the top wall which is sliding at constant velocity from left to right and the undulation which was induced at the bottom surface. It is found that these parameters have significant effect on the flow fields in the cavity. Furthermore, the trends of skin friction for different values of the aforementioned parameters are presented in this investigation.

In the present study the problem of mixed convection flow in the presence of magnetic field in a lid-driven square cavity with internal heat generation or absorption and uniform heating of bottom wall were investigated numerically. The square cavity vertical walls are maintained at cold temperature while the upper wall is insulated. The physical problem is then expressed mathematically by a set of governing equations and the developed mathematical model is solved by employing Galerkin weighted residual method of finite element formulation. Effects of variations of Richardson number, Hartmann number and heat generation or absorption parameter on flow structure and heat transfer rate (Nuesselt number) were studied in details. The significant reduction in the average Nusselt number were produced as the strength of the applied magnetic field was increased. In addition, heat generation predicted to decrease the average Nusselt number whereas heat absorption increases it.

Numerical study of flow friction and thermal behavior on a moving lid of a triangular cavity with various aspect ratios has been discussed using a Thermal Lattice Boltzmann Method (TLBM). To analyze the combined force and free convection, known as mixed convection, flows and heat transfer process in a lid driven triangular cavity with various aspect ratios AR(=L/H)=0.5, 1.0 and 2.0 are taken into account in the present study. The results are presented as stream function in terms of velocity, average heat transfer rate in terms of Nusselt number (Nu), and friction on moving lid of cavity for different Reynolds number (Re) as well as buoyancy parameter (λ). The heat transfer rate and friction on moving lid increased and decreased significantly with increasing Reynolds number and aspect ratios but they are linearly and very slowly changed with buoyancy effects. Similarly, the fluid flow behavior significantly changed with higher Reynolds number and aspect ratios compare to lower Re and AR. In addition, the less friction and more heat transfer occurred at case of free convection dominant case compare to forced convection dominant case. Similar behavior is observed for fluid flow analysis inside cavity. The model is validated by other numerical scheme and a very good agreement is found.