Numerical simulation of the flow around and through a hygroscopic porous circular cylinder

• Effects of adsorption due to the hygroscopicity of the porous cylinder are studied.
• The critical Reynolds number of porous cylinder might be lower than the solid one.
• Effects of adsorption have a significant effect on the flow behind the cylinder.
• The rise of temperature due to heat released effects the separation.

The flow around and through a hygroscopic porous circular cylinder was studied numerically in this paper. The cylinder is placed horizontally and exposed to a uniform flow of air. The effects of the important parameters, the hygroscopicity, the porosity, the Reynolds and Darcy numbers, on the flow are investigated in detail. A single-domain model is introduced to describe the flow around and through a porous circular cylinder with consideration of the adsorption effects. The flow is simulated by solving time-dependent Navier–Stokes equations in the homogenous fluid region and Darcy–Brinkman–Forchheimer extended model in the inner region. High order compact finite difference schemes are constructed for better simulation of this problem. Detailed numerical simulation results indicate that the effects of adsorption may have a significant effect on the flow behind the porous cylinder and suppress the occurrence of recirculating wake.