When the ratio of the Grashoff number and to the square of Reynolds number is one, the dominant mechanism of heat transfer is _______________?
Correct answer: C. Mixed convection (both free and forced)
- 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
Explanation
The ratio Gr/Re² compares buoyancy effects with forced-flow effects. When it is approximately one, both mechanisms are important, so the regime is mixed convection.
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