Question

Which number is analogous to Prandlt number in terms of mass transfer?

(a) Sherwood number

(b) Schmidt number

(c) Reynolds number

(d) Nusselt number

Answer 1

The correct choice is (b) Schmidt number

For explanation: Schmidt Number, Sc, is a dimensionless parameter representing the ratio of diffusion of momentum to the diffusion of mass in a fluid. It is defined as

Sc = v/δ

where ν is kinematic viscosity and &delta diffusivity.

Schmidt number is the mass transfer equivalent of Prandtl Number. For gases, Sc and Pr have similar values (≈0.7) and this is used as the basis for simple heat and mass transfer analogies.