Large Eddy Simulations (LES) - subgrid modeling problem - Aim: To model the large scales of a turbulent flow whilst accounting for the missing scales
{"Image DocumentName": "Large Eddy Simulations (LES) - subgrid modeling problem -", "Image ImageDescription": "Aim: To model the large scales of a turbulent flow whilst accounting for the missing scales in an appropriate way. Using a sharp spectral filter (Heaviside unit-step fn) =k0. Approx DNS limitations go as N~Re9/ > ~4000 Re. Pipe flow transition~2x103. Analogies with molecular properties I.e. modelling turbulence effects as a viscosity type term. Notice that while we want an eddy viscosity for our momentum equation to get some detailed dynamics, the subgrid eddy viscosity is usually calculated from the energy transfer equation I.e. from averaged quantities, so any phase information is lost.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}