Numerical Study of Heat and Mass Transfer of MHD flow over a stretching sheet


In this thesis, the boundary layer flow of Newtonian and non-Newtonian fluid models over unidirectional and bidirectional linearly stretching sheets are considered for the heat and mass transfer purpose. Upper convected Maxwell fluid model is used as a non-Newtonian fluid model. Flow is triggered due to linearly stretched sheet. For the enhancement of thermophysical properties of such fluids, the concept of nanofluid is utilized. Magnetic field is applied across the fluid flow which allows further manipulation of heat transfer and hydrodynamics characteristics. When the strong magnetic field is applied athwart the fluid having the low density, the conductivity of the fluid decreases because of the spiral movement of electrons about the lines of the magnetic force and the Hall current and ion-slip effects are produced. In addition, during the study of the nanofluids for the heat transfer purpose, the effects of thermal radiation cannot be denied. Particularly when there is a big temperature difference, we are encouraged to consider the non-linear thermal radiation. Further, the effects of heat generation/absorption, variable thermal conductivity, Joule heating, viscous dissipation and mixed convection are also contemplated for different problems. Using the boundary layer approximations, the physical flow model in the form of differential equations are governed. The partial differential equations which are non-linear in nature are reduced into a set of ordinary differential equations. Shooting technique with fourth order of Runga-Kutta integration scheme is used to calculate the numerical results of obtained differential equations. The quantities of physical significance such as velocities, concentration, temperature, Nusselt number, Sherwood number and skin-friction coefficients for various values of the emerging parameters, are computed numerically and are analyzed in detail. For the validation of the results obtained by the shooting method, a MATLAB built-in function bvp4c is also employed. Both the methods show an excellent agreement. To further strengthen the reliability of our MATLAB code, the results presented in the already published articles are reproduced successfully.

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