Heatline analysis for mixed convection flow of nanofluid within a driven cavity containing heat generating block

Abstract

Heat transfer enhancement in presence of nanofluid by the effect of mixed convection in a lid driven cavity are often encountered in engineering systems which has been studied numerically. A Cartesian co-ordinate system is used with the origin at the lower left corner of the computational domain. The system consists of a double lid driven cavity with a heat generating object centered at the origin. Upper and lower lids are kept adiabatic. Two cases are considered, for case I left and right lids are moving in upward direction while for case II upper and lower lids are moving in opposite direction. The governing equations are solved by employing a finite-element method based on Galerkin weighted residuals. The investigations are conducted for different values of Reynolds number, solid fluid thermal conductivity ratio, Richardson number, heat generation parameter and solid volume fraction. Streamlines, isotherms, heatlines and heat transfer rate in terms of the average Nusselt number (Nuav), average temperature (θav), maximum temperature, and the average heat flux magnitude for two above mentioned cases are presented for the aforesaid parameters. The results indicate that the mentioned parameters strongly affect the flow phenomenon and temperature field inside the cavity. Comparisons with previously published work are performed and the results are found to be in excellent agreement.