Heat transfer through mixed convection boundary layer in a porous medium: LTNE analysis

Abstract

This paper concerns the LTNE model for two-dimensional mixed convection boundary layer flow of a viscous fluid over a wedge embedded in the porous medium. The temperature for the fluid and solid field is governed by the two separate energy equations: one each for fluid and solid phase due to LTNE condition. Since the flow velocity is sufficiently large, the momentum and thermal boundary layers form near the wedge surface. The resulting mathematical equations in terms of partial differential equations are converted into equivalent ordinary differential equations using appropriate similarity transformations and are solved numerically. Numerical results on various physical quantities reveal that the LTNE effects are more predominant for small inter-phase heat transfer rate and porosity scaled conductivity. For mixed convection thermal boundary layer flow, LTNE effects are not as strong as for forced convection heat transfer. However, when the inter-phase interaction and porosity-scaled conductivity are increased, the LTE is recovered for which both solid and fluid phases become almost equal. Simulations on velocity profiles show that the pressure gradient and permeability have less effects on the boundary layer but cannot be neglected. The physical dynamics behind these effects are discussed in some detail.