CMS-Flow:Subgrid Turbulence Model

From CIRPwiki
Jump to navigation Jump to search

Eddy Viscosity

In CMS-Flow eddy viscosity is calculated as the sum of the kinematic viscosity , the current-related eddy viscosity and the wave-related eddy viscosity

     

There are two options to calculate . The first is the Falconer (1980) equation given by


     


where is the bottom friction coefficient, is the depth-averaged current velocity, and is the total water depth.

The second option is a subgrid turbulence model given by

     

where is an empirical coefficient approximately equal to 1/6, is an empirical coefficient between 0.25-0.5, and are the grid dimensions in the x and y directions and is equal to

     

The wave component of the eddy viscosity is calculated as

     

where is an empirical coefficient, is the water density, and is the total wave dissipation.



CMS-Flow