申論題

5. What are the definitions of the following terms? (10%) (a) Friction coefficient； (b) Biot number； (c) Stanton number； (d) Nusselt number； (e) Prandtl number. [Example]: Reynolds number, Re_D= puD/μ, where r: fluid density, u: flow velocity, D: tube diameter, and u: fluid viscosity.