Turbulence modeling and the physics of the Intra-cluster medium

Abstract

The effective modeling of the stirring and development of turbulent flows in grid-based hydrodynamical simulations is computationally challenging. Here we present two possible ways to tackle the problem: first, we consider the use of the adaptive mesh refinement (AMR), applying novel refinement criteria which are optimized to follow the evolution of a turbulent flow. In a second step, the AMR is combined with a subgrid scale (SGS) model for the unresolved turbulence, thus resulting in a new numerical technique called FEARLESS (Fluid mEchanics with Adaptively Refined Large Eddy SimulationS). FEARLESS performs both the adaptive refinement of the regions where turbulent flows develop and a consistent coupling of the SGS turbulence with the resolved scales, and is argued to be a suitable tool in simulations of turbulent clumped flows. The results of galaxy cluster simulations, performed with the new tool, give rise to several interesting implications with regard to the physics of these objects, and to the numerical methods employed for their exploration in computational cosmology.