Biot Number Calculator
Free calculate the biot number to analyze heat transfer characteristics and determine if a body can be treated as having uniform temperature.
Input Parameters
For a sphere: radius/3, For a cylinder: radius/2, For a plate: thickness/2
Results
Enter parameters to calculate Biot number
Biot Number Formula
Formula
Bi = (h × L) / k
Where:
- • Bi = Biot number (dimensionless)
- • h = convective heat transfer coefficient
- • L = characteristic length
- • k = thermal conductivity
Interpretation
- • Bi < 0.1: Lumped capacitance valid (uniform temperature)
- • 0.1 < Bi < 100: Spatial temperature variation
- • Bi > 100: Surface temperature ≈ fluid temperature