Effects of cylinder location and size on MHD natural convection flow in a square cavity

Abstract

Heat transfer phenomenon in a square cavity with MHD natural convection flow has been over looked numerically. In this research under the title “Effects of cylinder location and size on MHD natural convection flow in a square cavity”, two cases have been considered: (I) Variation of cylinder’s position vertically keeping size (radius, r) of the cylinder as a constant and (II) Variation of cylinder size (radius, r) keeping cylinder position at (0.50, 0.50) as a constant. The bottom wall of the cavity and the cylinder has kept at high temperature (Th) and the rest of the walls have remained at low temperature (Tc). The research has been performed for different values of Rayleigh number (Ra), Hartmann number (Ha), Prandtl number (Pr), physical parameter: size (radius) of the heated cylinder (r) and various position of the heated cylinder. The numerical results have been reported for the effect of buoyancy parameter, Rayleigh number ( ), magnetic field parameter, Hartmann number ( ) and the thermal diffusivity parameter, Prandtl number ( ). Three positions (0.50, 0.25), (0.50, 0.50) and (0.50, 0.75) of the heated cylinder have been considered in the case (I) where the size (radius, r) of the cylinder has maintained as a constant (r = 0.20 m). Besides, in case (II), the size (radius, r) of the heated cylinder has been altered from r = 0.10 to 0.30 m keeping cylinder position at (0.50, 0.50) as a constant. The strength of the velocity magnitude has been improved for both cases with the increase of Rayleigh number (Ra) and Prandtl number (Pr). But the strength of the velocity magnitude has been declined for both cases with the increase of Hartmann number (Ha). The maximum (184 m/s) average velocity magnitude (Vav) in the cavity has been observed when cylinder size, r = 0.30 m, CP at (0.50, 0.50), Ra = 5×106, Pr = 0.71 and Ha = 50. Finally, appreciable effects of heat transfer rate have been illustrated for the size variation of the heated cylinder compared to the position variation. Evaluations with earlier published work have been executed and the results have found to be in good agreement.