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PurposeThis paper aims to predict the effects of uniform injection or suction through a porous square cylinder on the flow field and on some aerodynamic parameters.Design/methodology/approachThe finite volume method has been used for solving the ensemble averaged Navier–Stokes equations for incompressible flow in conjunction with the k‐ ε turbulence model equations including the Kato and Launder modification.FindingsThe parameters taken into account are injection or suction velocity, position of injection and suction surface, drag and lift coefficients and Strouhal number. The numerical results show that increasing suction velocity decreases the drag coefficient for all the suction configurations considered in the present study, except that of suction through rear surface. The vortex‐shedding motion gets weak by the suction application through top and bottom surfaces.Research limitations/implicationsThe problem is restricted with a 2‐D simple geometry such as square cylinder due to the limited computer capability. Further extensions of the present study could include the more complex configurations and some other aspects such as heat transfer between porous cylinder and main flow.Practical implicationsThe injection or suction application through a porous bluff body can be used as an efficient drag and vortex control method in aerodynamics.Originality/valueThis paper describes an attempt to simulate numerically the flow around square cylinder with uniform injection and suction in a manner different from what is given in the literature.

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The hydrodynamic and thermal characteristics of the turbulent boundary layer developed on a porous wall with heat transfer and various angles of transpiration are analyzed numerically with the proper boundary conditions. The wall functions of the viscous and turbulent sub-layers for velocity and temperature are modified to allow for the effect of the angle of injection and suction through the porous wall. The finite difference method based on a control volume approach is used for solving the time averaged Navier-Stokes equations for incompressible flow in conjunction with the standard k-1 turbulence model equations. A non-uniform staggered grid arrangement is used. The parameters studied include the suction and injection velocity (V w ) and the angle (a) of the injection and suction. The present numerical results of the normal injection and suction are compared with a known experimental data and a good agreement is obtained. The numerical results also indicate that the characteristics of the turbulent boundary layer such as local friction coefficient and thermal boundary layer thickness are substantially influenced by the velocity and the angle of transpiration.

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