Calculate the ratio of convective to conductive heat transfer across a boundary.
System Parameters
W/m²K
m
W/mK
Calculation Results
Enter parameters to calculate Nusselt Number
About this calculator
Quick Reference
NuNusselt Number
hConvective heat transfer coeff
LCharacteristic length
kThermal conductivity of fluid
Overview
The Nusselt number is a dimensionless parameter used in heat transfer. It represents the ratio of convective heat transfer to conductive heat transfer across a fluid layer. A Nusselt number of 1 signifies heat transfer by pure conduction.
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Pro Tips
h is the convective heat transfer coefficient in W/(m²·K).
L is the characteristic length in meters.
k is the thermal conductivity of the fluid in W/(m·K).
Higher Nusselt numbers indicate more effective convection (e.g., turbulent flow).
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Fun Facts
"It is named after Wilhelm Nusselt, a German engineer who made significant contributions to the theory of heat transfer."
"The Nusselt number is often expressed as a function of the Reynolds and Prandtl numbers in forced convection: Nu = f(Re, Pr)."
"In natural convection, it is expressed as a function of the Grashof and Prandtl numbers."
