Heat transfer co-efficient equation for forced convection, Nu = 0.023 Re 0.8. Pr n, is not valid, if the value of __________________?
Correct answer: C. Reynolds number for the flow involved is < 2100
- A. n = 0.4 is used for heating
- B. n = 0.3 is used for cooling
- C. Reynolds number for the flow involved is < 2100
- D. Reynolds number for the flow involved is > 10000
Explanation
The Dittus-Boelter correlation is intended for turbulent flow, typically with Reynolds number above about 10,000. A Reynolds number below 2,100 indicates laminar flow, so the correlation is not valid there.
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