The Sherwood Number is defined as what?

The Sherwood Number is defined as what?

• A. Ratio of diffusive mass transport to convective mass transport
• B. Ratio of viscous forces to inertial forces
• C. Ratio of thermal diffusivity to mass diffusivity
• D. Ratio of convective mass transport to diffusive mass transport

Answer: (D)

The Sherwood number tells you how strong convection is compared with diffusion for moving a species between a surface and the surrounding fluid. It quantifies the actual mass transfer rate by convection relative to what would happen if diffusion alone did the job. The standard definition is Sh = kL / D_AB, where k is the overall mass-transfer coefficient, L is a characteristic length, and D_AB is the diffusivity of species A in B. Put simply, it’s the ratio of the convective transport rate (kL) to the diffusive transport rate (D_AB). When the flow carries a lot of material with it, convection dominates and Sh becomes much greater than 1; when diffusion dominates, Sh approaches 1. This concept is analogous to the Nusselt number in heat transfer, showing how much convection enhances mass transfer beyond pure diffusion.

The Sherwood number tells you how strong convection is compared with diffusion for moving a species between a surface and the surrounding fluid. It quantifies the actual mass transfer rate by convection relative to what would happen if diffusion alone did the job. The standard definition is Sh = kL / D_AB, where k is the overall mass-transfer coefficient, L is a characteristic length, and D_AB is the diffusivity of species A in B. Put simply, it’s the ratio of the convective transport rate (kL) to the diffusive transport rate (D_AB). When the flow carries a lot of material with it, convection dominates and Sh becomes much greater than 1; when diffusion dominates, Sh approaches 1. This concept is analogous to the Nusselt number in heat transfer, showing how much convection enhances mass transfer beyond pure diffusion.