Modelling of turbulent flow over porous media using a volume averaging approach and a Reynolds stress model

• Derivation of compressible volume averaged RANS equations for flow in porous media.
• Extension of Reynolds stress turbulence model for simulations in porous media.
• Correction of mean-flow and all turbulence quantities at nonporous–porous interface.
• Calibration of new modelling parameters with DNS data of a partly porous channel.

A computationally efficient method to simulate high Reynolds number aerodynamic flows over porous surfaces is investigated. The approach is based on volume and Reynolds averaging of the compressible Navier–Stokes equations. Effects of the porous medium are modelled by the Darcy and Forchheimer terms. Turbulence is modelled by a Reynolds stress model with additional terms by virtue of present porous media. At the nonporous–porous interfaces a jump condition is applied to the momentum and turbulence equations. This correction models the effects of porosity gradients which are not considered in the derivation of the governing equations. Also, the implementation of the models into a compressible flow solver is described. Finally, the computational model is validated by comparisons with geometry resolved and volume-averaged DNS computations of a channel flow. Subsequently, the effects of the modelling parameters are analysed with respect to their sensitivities to the flow solutions.