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

Purpose - The 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/approach - The 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. Findings - The 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 beta has a more noticeable effect, whereas the second coefficient beta(1) has very small effect, even for Re = 200. Originality/value - The 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.