A. Nst α f
B. Nst α NRe
C. NNu α f
D. NRe α f
Related Mcqs:
- According to Reynolds analogy, Stanton number is equal to (where, f = Fanning friction factor) ?
A. 2f
B. f
C. f/2
D. f/4 - Prandtl and Reynolds analogy are same, when Prandtl number is____________________?
A. 0.5
B. 1
C. > 2
D. 1.5 - 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 - 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 - 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 - 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 - 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 - The equation, (NSt × N2/3 Pr) = f/2, is the ____________ analogy ?
A. Colburn
B. Reynolds
C. Prandtl
D. None of these - 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 - 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.
