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Heat Transfer By Convection is heat transfer by mass motion of a fluid such as air or water when the heated fluid is caused to move away from the source of heat, carrying energy with it.
The calculator uses the formula:
Where:
Explanation: This formula calculates convection heat transfer by dividing conduction heat transfer by the Graetz number, which characterizes the ratio of heat transfer by convection to conduction in fluid flow systems.
Details: Accurate calculation of convection heat transfer is crucial for designing heat exchangers, cooling systems, and various thermal management applications in engineering and industrial processes.
Tips: Enter Heat Transfer By Conduction in W/m²K and Graetz Number (dimensionless). Both values must be positive numbers greater than zero.
Q1: What is the Graetz Number?
A: The Graetz number is a dimensionless number used in fluid dynamics and heat transfer that characterizes the ratio of heat transfer by convection to conduction in developing flow in ducts.
Q2: What are typical values for convection heat transfer coefficients?
A: Convection heat transfer coefficients vary widely depending on the fluid and flow conditions, ranging from 5-25 W/m²K for natural convection in air to 500-15,000 W/m²K for forced convection in liquids.
Q3: When is this formula typically used?
A: This formula is commonly used in thermal engineering applications involving internal flow in pipes and ducts, particularly for analyzing heat transfer in developing thermal boundary layers.
Q4: Are there limitations to this equation?
A: This simplified relationship assumes specific flow conditions and may not be accurate for all scenarios, particularly in complex flow geometries or with significant property variations.
Q5: How does convection differ from conduction heat transfer?
A: Conduction involves heat transfer through a stationary medium by molecular interactions, while convection involves heat transfer through the bulk motion of a fluid carrying thermal energy.