Nusselt number (and film coefficient h) for turbulent pipe flow: Nu = 0.023·Re^0.8·Pr^n (n = 0.4 heating, 0.3 cooling).
Formula
$$ Nu = 0.023 \cdot Re^{0.8} \cdot Pr^n, \quad h = \frac{Nu \cdot k}{D_h} $$
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| $Re$ | Reynolds number | - | fluid flow |
| $Pr$ | Prandtl number = ν/α | - | fluid property |
| $k$ | Thermal conductivity | W/(m·K) | fluid table |
| $D_h$ | Hydraulic diameter | m | geometry |
| $h$ | Convective film coefficient | W/(m²·K) | result |
Sources
- Dittus-Boelter (1930).