Eulerian time-domain filtering for spatial large-eddy simulation

An approach to large-eddy simulation is developed whose subgrid-scale model incorporates Eulerian time-domain filtering, in contrast to conventional a pproaches that exploit spatial filtering. For applications to large-eddy si mulation, time-domain filters enjoy certain advantages relative to spatial filters, Among these, they more naturally commute with differentiation oper ators than do spatial filters, and there is typically wide separation betwe en numerical truncation error and the dissipation of the subgrid-scale mode l. Eulerian time-domain filtering is most appropriate for flows whose large coherent structures convect approximately at a common characteristic veloc ity. Such Rows include jets, mixing layers, and wakes. The method is demons trated in the large-eddy simulation of a heated, subsonic, axisymmetric jet , and results are compared with those obtained from well-resolved direct nu merical simulation.