On The Predictability Of Turbulent Mixing With Implicit Large Eddy Simulation

Under resolved computer simulations are typically unavoidable in many practical turbulent flow applications exhibiting extreme geometrical complexity and broad ranges of length and time scales. In such applications, coarse grained simulation becomes the effective simulation strategy, mostly by necessity rather than by choice. In coarse grained simulation strategies, resolved/unresolved scale separation is assumed possible, large energy containing structures are mostly resolved, smaller structures are spatially filtered out, and unresolved subgrid effects are modeled. The subject of this work is on implicit large-eddy simulation which relies on subgrid modeling implicitly provided by physics capturing numerical algorithms. Predictability issues of coarse grained simulation from the perspective of implicit large-eddy simulation of under resolved mixing of material scalars driven by under resolved velocity fields and initial conditions are addressed. The performance of implicit large-eddy simulation in the contexts of forced scalar mixing, transition to turbulence and turbulence decay, and shock-driven turbulent mixing is the particular focus.