Summary: Enable a scalar diffusion model that uses the Schmidt Number.
Flag
TURB_SCALAR A
A = 0: (default) causes the default scalar equation to be used with the specified diffusion coefficient. (To enable the scalar and specify the diffusion coefficient, open the Solve dialog, and click the Physics tab. Open the Advanced dialog, and click General Scalar.
A = 1: Changes the scalar equation to be based on the turbulent viscosity (mean eddy viscosity).
Description
In most scalar concentration studies, the default numerical model and specified diffusion coefficient are suitable.
In some scalar mixing models, however, the scalar quantity appears to propagate near the walls faster than through the core flow. This is more likely to occur when the Schmidt Number is greater than 100.
Schmidt Number = Viscosity / (Density * Diffusion Coefficient)
To account for local turbulence effects, change the scalar diffusion correlation using this flag.