Numerical analysis for the flow past a porous trapezoidal‐cylinder based on the stress‐jump interfacial‐conditions

Abstract

PurposeThe paper aims to report on the flow past a porous trapezoidal‐cylinder, in which the porous‐fluid interface was treated by implementing the stress jump boundary conditions.Design/methodology/approachThe numerical method was based on the finite‐volume method with body‐fitted and multi‐block grids. The Brinkman‐Forcheimmer extended model was used to govern the flow in the porous medium region. At its interface, a shear stress jump that includes the inertial effect was imposed, together with a continuity of normal stress.FindingsThe present model was validated by comparing with those for the flow around a solid circular cylinder. Results for flow around porous expanded trapezoidal cylinder are presented with flow configurations for different Darcy number, 10−2 to 10−7, porosity from 0.4 to 0.8, and Reynolds number 20 to 200. The flow develops from steady to unsteady periodic vortex shedding state. The first coefficient β has a more noticeable effect, whereas the second coefficient β1 has very small effect, even for Re   =   200.Originality/valueThe effects of the porosity, Darcy number and Reynolds number on lift and drag coefficients, and the length of circulation zone or shedding period are studied.