Prace Call: 17th
ID: 2018184468, Leader: Sergio Pirozzoli
Affiliation: Sapienza University of Rome, IT
Research Field: Engineering
Collaborators: Paolo Orlandi Sapienza, University of Rome IT , Davide Modesti University of Melbourne AU , Antonio Memmolo Sapienza, University of Rome IT , Simone Di Giorgio Sapienza, University of Rome IT
Resource Awarded: 40 Mil. core hours on Marconi - KNL
We carry out pore-resolving direct numerical simulations (DNS) of turbulent channel flow over a permeable bed, using an incompressible Navier-Stokes solver relying on immersed-boundary representation of complex geometries. Unlike all previous studies, the flow in the porous material is directly resolved accounting for its full geometrical complexity, rather than modeled through an ad-hoc set of equations. Additional physical insight will be gained through higher fidelity coupling of the flow within the channel and within the porous bed, hence avoiding the prescription of fictitious jump conditions for the tangential stresses which are known to be affected by large uncertainty. Numerical simulations will be carried out for several types of porous beds, including: i) foams with random spherical pores; ii) granular media with spherical pores, either self-intersecting or not. Different values of the medium porosity will be considered, as well as different values of the pore size in the range from 0.05 h to 0.2 h (where h is the channel half-height). Numerical simulations with assigned p.d.f. of the pore/void radius will also be carried out to mimic realistic flow cases. Access to PRACE resources will allow to compile a comprehensive database covering 44 geometries, at shear Reynolds number up to Reτ = 1000, thus significantly widening the current DNS envelope for this class of flows, so far limited to the canonical value of 180.