Nusselt Number Calculator

Find the Nusselt number for convective heat transfer.

Heat transfer coefficient (W/(m²·K))

Characteristic length

Thermal conductivity (W/(m·K))

Nusselt number 16.667

Formula: Nu = h·L ÷ k

Step-by-step with your numbers:

1. Values used:

2. Heat transfer coefficient = 100 W/(m²·K)

3. Characteristic length = 0.1

4. Thermal conductivity = 0.6 W/(m·K)

6. Heat transfer coefficient x Characteristic length = 100 x 0.1 = 10

7. Nusselt number = (Heat transfer coefficient x Characteristic length) / Thermal conductivity = 10 / 0.6 = 16.667

Did we solve your problem today?

The Nusselt number compares convective to conductive heat transfer.

The math behind it

Nu = h·L ÷ k. Nu = 1 means pure conduction; higher values mean convection dominates.

h 100, L 0.1 m, k 0.6 → Nu ≈ 16.7.

How is it used?

Correlations give Nu from Reynolds and Prandtl numbers, then h = Nu·k/L.