FLOW: WALLPART – Inertial Particles in developing wall turbulence

Traditionally, direct numerical simulations (DNS) of turbulent flows are performed in simplified computational domains that are characterised by periodic boundary conditions in all three directions. However, real applications in nature and technology often involve the interaction with a solid wall and are thus inhomogeneous is space. Here, we study the flow case of a spatially evolving turbulent boundary layer and focus on the combined advection of inertial particles. Such a computational study based on highly resolved DNS and not yet attempted in the literature, bears many interesting and relevant physical effects due to the growing boundary layer; for instance the non-dimensional number characterising the particle-wall accumulation is gradually changing with the downstream distance. The raw scientific data is planned to be shared with the scientific community (iCFDdatabase, http://cfd.cineca.it). From a computational point of view, spatially developing flows are necessarily investigated in very long domains in order to accurately capture the whole streamwise extent of the (physical) flow; another problem is the reliable and trustworthy generation of inflow turbulence in a non-periodic setting. It is thus only recently that the DNS of turbulent boundary layers has become feasible. The additional complexity of coupling the advection of inertial particles leads to large computational demands on massively parallel computers.

This project has been granted computer time on the Cray Xe6 computer at EPCC Edinburgh, Scotland. For the simulations, we are using a new hybrid parallelised version of the SIMSON code. The project is in collaboration with Carlo Casciola (University of Rome) and Hans Kuerten and Federico Toschi (TU Eindhoven).