ANS:C - Schmidt number

The Brinkman number, Stanton number, Schmidt number, and Peclet number are all dimensionless numbers used in fluid mechanics and heat transfer to characterize different aspects of the flow and heat transfer processes. Among these options, the Schmidt number is not directly concerned with heat transfer. Instead, it relates to mass transfer, specifically the relative importance of momentum and molecular diffusion in a fluid flow. It is defined as the ratio of momentum diffusivity to mass diffusivity. So, the correct answer is: "Schmidt number"