According to Reynolds analogy, Stanton number is equal to (where, f = Fanning friction factor) ?

Related Mcqs:

1. Reynold’s analogy states that (where, St = Stanton number f = friction factor) ?

   A. St = f/2
   B. St = f/4
   C. St = 4f
   D. St = f1/2

2. All analogy equations connecting friction factor and heat transfer co-efficient apply only to ___________________?

   A. Wall or skin friction
   B. Form friction
   C. Both A. and B.
   D. Turbulent flow

3. Prandtl and Reynolds analogy are same, when Prandtl number is____________________?

   A. 0.5
   B. 1
   C. > 2
   D. 1.5

4. The Sieder-Tate correlation for heat transfer in turbulent flow in pipe gives Nu α Re0.8, where, Nu is the Nusselt number and Re is the Reynolds number for the flow. Assuming that this relation is valid, the heat transfer co-efficient varies with the pipe diameter D. as _________________?

   A. D-1.8
   B. D-0.2
   C. D0.2
   D. D1.8

5. When the ratio of the Grashoff number and to the square of Reynolds number is one, the dominant mechanism of heat transfer is _______________?

   A. Free convection
   B. Entry length problem in laminar forced conduction (developing thermal boundary layer)
   C. Mixed convection (both free and forced)
   D. Forced convection

6. If the baffle spacing in a shell and tube heat exchanger increases, then the Reynolds number of the shell side fluid_________________?

   A. Remains unchanged
   B. Increases
   C. Increases or decreases depending on number of shell passes
   D. Decreases

7. When does the heat generated by fluid friction becomes appreciable compared to the heat transferred between the fluids ?

   A. At high fluid velocity
   B. At low velocity
   C. When fluid flows past a smooth surface
   D. None of these

8. The equation, (NSt × N2/3 Pr) = f/2, is the ____________ analogy ?

   A. Colburn
   B. Reynolds
   C. Prandtl
   D. None of these

9. For what value of Prandtl number, the Col-burn analogy is valid ?

   A. 0.06 to 120
   B. 0.6 to 120
   C. 1 to 103
   D. 1 to 50

10. Analogy between mass and heat transfer is not applicable in case of____________________?

    A. Same velocity profile or equal eddy diffusivities
    B. Thermal or pressure mass diffusion
    C. Viscous heating or chemical reaction
    D. Both B. and C.