Effects of buoyancy and conjugate heat transfer on non-Darcy mixed convection about a vertical slender hollow cylinder embedded in a porous medium with high porosity

摘要

This study investigates mixed convection heat transfer about a vertical slender hollow cylinder in the buoyancy and conjugate heat transfer effects in the porous medium with high porosity. The non-similar solutions using the Keller box method are obtained. The wall conduction parameter p, the porous med-ium parameter k_1, the Forchheimer parameter F* and the Richardson number are the main parameters. For various values of these parameters the local skin friction and local heat transfer parameters are deter-mined. The validity of the methodology is checked by comparing the results with those available in the open literature and a fairly good agreement is observed. Finally, it is determined that the local skin fric-tion and the local heat transfer coefficients increase with an increase buoyancy parameter Ri, porous medium parameter k_1, Forchheimer parameter F* and decrease with conjugate heat transfer parameter p.