The Schmidt number compares momentum diffusion with molecular mass diffusion.
Difficulty
Intermediate
Read time
4 min
Prerequisites
Consistent SI units, algebra, and the physical assumptions listed below
Source
Teng-Jui Lin — Equation SheetsAdapted from Teng-Jui Lin, Equation Sheets — Mechanical Engineering, under CC BY 4.0.
Adapted notation and added original explanations, variables, assumptions, applications, and a worked example.
The Schmidt number compares momentum diffusion with molecular mass diffusion. Large values indicate that momentum spreads faster than a dissolved species, which is useful when interpreting concentration boundary layers.
| Symbol | Meaning | Units |
|---|---|---|
| Schmidt number | ||
| Kinematic viscosity | ||
| Binary mass diffusivity of A in B |
Supply Sc in a suitable Sherwood-number correlation.
Compare viscous and concentration diffusion time scales.
A liquid mixture has ν = 1.0 × 10⁻⁶ m²/s and D_AB = 2.0 × 10⁻⁹ m²/s. Find Sc.
Adapted from Teng-Jui Lin, Equation Sheets — Mechanical Engineering, under CC BY 4.0.
Adapted notation and added original explanations, variables, assumptions, applications, and a worked example.
Assumptions
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