Convective Heat Transfer from a Porous Semi‐Circular Obstacle Attached to a Channel Wall

Abstract

Two-dimensional forced convection heat transfer from a heated porous semicircular obstacle attached to the adiabatic channel wall is numerically studied in the laminar and steady flow regime. The fluid is assumed to be Newtonian and incompressible. The aggregate influences of the chosen ranges of Prandtl number (Pr), Darcy number (Da), porosity (e), Reynolds number (Re), and the blockage ratio (b) of the channel are explored. The Darcy-Brinkman-Forchheimer model is implemented to tackle the flow through the porous obstacle and the obtained governing equations are solved by FEM-based COMSOL Multiphysics. The complex thermal field is illustrated through the isotherm contours, local and average Nusselt number. The front part of the obstacle contributes to the maximum heat transfer. Pr, Re, and the blockage ratio have a positive impact on heat transfer at a small value of Da.

Influence of Planar Confinement on Momentum and Heat Transfer from a Blunt‐Headed Cylinder to Generalized Newtonian Fluids

“…i.e., Pr is dependent on the value of n . This behavior can be attributed to the depletion of the boundary layer in shear‐thinning fluids, as supported by previous studies 30, 35, 50.…”

“…The effects of these parameters become more prominent as Re increases and Pr deviates from its reference value. i.e., Pr is dependent on the value of n. This behavior can be attributed to the depletion of the boundary layer in shear-thinning fluids, as supported by previous studies[30,35,50].Additionally, the local Nusselt number Nu, which represents the convective heat transfer coefficient calculated at a specific location on the blunt-headed cylinder surface, provides valuable insights into the heat transfer rate from the cylinder to the surrounding fluid. The local Nu values are influenced by several factors, including Re, n, Pr, and b.…”

“…A comprehensive review of the literature reveals well-recognized experimental, analytical, and numerical studies on forced convection from circular and noncircular cylinders in Newtonian and/or non-Newtonian fluids. These studies cover various cylinder geometries, including circular [11][12][13][14][15][16][17][18], elliptic [19,20], square [21][22][23][24], triangular [25,26], semicircular [27][28][29][30][31][32], and others. The literature also reports the impact of confinement on the flow around a circular cylinder, which has been studied across a wide range of low to high Reynolds numbers [13,28,29,[31][32][33][34][35][36][37][38][39][40][41].…”

“…On the contrary, numerous studies have been conducted to explore the momentum and heat transfer characteristics of noncircular cylinders, including square cylinders [21][22][23][24], semicircular cylinders [27][28][29][30][31][32], triangular cylinders [25,26], and more. These studies have investigated the behavior of Newtonian and non-Newtonian fluids in the vicinity of these confined and unconfined noncircular geometries.…”