Definition
• Schmidt Number—Ratio of momentum diffusivity (kinematic viscosity) to species (mass) diffusivity.
where
 | density kg/m3 |
 | dynamic viscosity Pa-s |
 | diffusivity m2/s |
• Turbulent Schmidt Number—Ratio of the eddy viscosity to the eddy diffusivity.
where,
 | density kg/m3 |
 | dynamic turbulent viscosity kg/m-s |
 | kinematic turbulent viscosity m2/s |
 | turbulent mass diffusivity m2/s |
• Convective Flux— Boundary condition, in which the transported flux of scalar 
per unit area, is a function of the external ambient concentration and an exchange coefficient:
per unit area, is a function of the external ambient concentration and an exchange coefficient:
where,
 | scalar flux kg/m2-s |
 | convective transport coefficient kg/m2-s |
 | ambient value of scalar  |
 | The value of the scalar  is also referred to as concentration when you view results or plots. |