Chemical Engineering - Heat Transfer

21.
The equivalent diameter for the annulus of a double pipe heat exchanger, whose inner pipe has fins on the outside is __________ compared to the same size pipes without fins.
more
less
same
unpredictable
Answer: Option
Explanation:
No answer description is available. Let's discuss.

22.
Natural convection is characterised by
Grashhoff number
Peclet number
Reynolds number
Prandtl number
Answer: Option
Explanation:
No answer description is available. Let's discuss.

23.
Nusselt number for full developed, laminar, constant property flow in a pipe at uniform heat flux is
0.72
4.364
18
83
Answer: Option
Explanation:
No answer description is available. Let's discuss.

24.
Thickness of thermal boundary layer is more compared to that of hydrodynamic boundary layer, when the value of Prandtl number is
1
< 1
> 1
> 5
Answer: Option
Explanation:
No answer description is available. Let's discuss.

25.
The critical radius of insulation for cylindrical pipe is (where, hi = heat transfer coefficient at inside of the pipe )
K/h0
2K/h0
hi/K
2hi/K
Answer: Option
Explanation:
No answer description is available. Let's discuss.