Air Flow around and through a Permeable Semi‐Circular Cylinder^‡

Abstract

An unconfined air flow across a semi-circular permeable/porous cylinder is numerically investigated for different Reynolds (Re) and Darcy numbers (Da) at a fixed value of porosity. The Darcy-Brinkman-Forchheimer model has been administered to deal with the flow field inside the porous cylinder. The governing equations are solved by using the finite element method-based commercial software COMSOL Multiphysics. The obtained flow field is analyzed by streamline profiles and vorticity contours. The collective impact of Re and Da on the drag coefficient is evaluated. At low Da values, the cylinder resembles the solid cylinder as the vorticity contours and streamlines do not infiltrate the porous media. The increment in Da leads to penetration of streamlines and vorticity contours through the porous cylinder. The drag coefficient retained an inverse relationship with Re and showed a complex relationship with Da.

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

“…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].…”

“…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]. The studies demonstrate that the presence of plane walls significantly influences hydrodynamic parameters such as drag force and vortex shedding frequency (the Strouhal number).…”

“…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.…”