Schmidt number is termed as a dimensionless number that is defined as the ratio of momentum diffusivity or viscosity and mass diffusivity. The Schmidt Number is denoted by the symbol "Sc". In short, Schmidt Number is physically related to the relative thickness of the hydrodynamic layer and mass-transfer boundary layer.
Schmidt Number :
Sc = v/ D
_{c}
Kinematic Viscosity :
v = Sc*D_{c}
Mass Diffusivity :
Dc = v/Sc
Where,
Sc = Schmidt Number,
v = Kinematic Viscosity,
D_{c} = Mass Diffusivity.
The Schmidt Number is used to characterize fluid flows in which there are simultaneous momentum and mass diffusion convection processes. The Schmidt Number is named after the German engineer Ernst Heinrich Wilhelm Schmidt (1892-1975).
Example:
Calculate the Schmidt number for the given details.
Kinematic Viscosity (v) = 15 m^{2}/s
Mass Diffusivity (D_{c}) = 10 m^{2}/s
Solution:
Apply Formula:
Sc = v/ D_{c}
Sc = 15/10
Sc = 1.5
Schmidt Number (Sc) = 1.5