Al-Qadisiyah Journal for Engineering Sciences

Abstract The purpose of this investigation is to determine if adding an isolated cylinder to the domain can improve forced convection in the laminar case of the sudden expansion flow in a two-dimensional channel. The range of the Reynolds number (1-200) and the number of prattle 0.71, the impact of different cross-stream locations (x=10.4,10.8 and 11.2) of the circular cylinder on the flow, and thermal properties of the sudden expansion flow have been computationally studied (air). COMSOL Multiphysics is utilized to address the governing continuity, Navier-Stokes, energy equation of energy, and the necessary boundary conditions. Although streamline and isotherm profiles have been used to describe the flow and thermal fields, the temperature dependence of the flow viscosity and thermal conductivity has not been taken into account. The findings presented here demonstrate an improvement in the peak Nusselt value when a circular cylinder is used in comparison to the unobstructed condition.

Abstract Investigate the symmetry-breaking flow bifurcation phenomena and its control of an electrically conducting generalized Newtonian liquids flowing through symmetric sudden expansion channel by applied magnetic field in the transverse direction studied in this paper. The governing nonlinear magnetohydrodynamic equations simplified for low conducting liquid metals are written and solved numerically using PISO-GNFMHD algorithm, which was developed by the author to include generalized Newtonian fluids, as well as the effects of the magnetic field on the fluid flow based on the finite volume method. The effects of non-Newtonian rheology and the magnetic force on flow bifurcation and separation are studied. In case of power-law fluid model the flow transition depends nonlinearly on shear viscosity in particular the shear-thickening fluids delay the onset of bifurcation where as shear-thinning fluids the early flow transition is occurred. The magnetic force is always delay this transition. The main conclusion is the possibility to control the phenomenon of bifurcation finally by applying an external magnetic field.