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Nusselt Number Formula:
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The Nusselt Number for constant heat flux is a dimensionless number that represents the ratio of convective to conductive heat transfer at a boundary in a fluid under constant heat flux conditions. It is particularly important in heat transfer analysis for systems with uniform heat generation.
The calculator uses the Nusselt Number formula:
Where:
Explanation: This empirical correlation relates the Nusselt number to the product of Reynolds and Prandtl numbers, providing an estimate of convective heat transfer efficiency under constant heat flux conditions.
Details: Accurate Nusselt number calculation is crucial for designing heat exchangers, cooling systems, and other thermal management applications where constant heat flux conditions prevail.
Tips: Enter Reynolds Number based on diameter and Prandtl Number. Both values must be positive numbers for valid calculation.
Q1: What is the range of validity for this correlation?
A: This correlation is typically valid for Reynolds numbers between 10,000 and 100,000 and Prandtl numbers between 0.7 and 160.
Q2: How does constant heat flux differ from constant temperature?
A: Constant heat flux maintains a fixed heat transfer rate per unit area, while constant temperature maintains a fixed boundary temperature, leading to different Nusselt number correlations.
Q3: What are typical Nusselt number values?
A: Nusselt numbers typically range from 1 (pure conduction) to several hundred (strong convection), depending on flow conditions and fluid properties.
Q4: When is this correlation most applicable?
A: This correlation is particularly useful for internal flows in pipes and channels with uniform heating or cooling along the surface.
Q5: Are there limitations to this equation?
A: This correlation may not be accurate for very low or very high Reynolds numbers, or for fluids with extreme Prandtl numbers outside the typical range.