Model-Ship Correlation Allowance ΔC_F
Hull-roughness correlation allowance ΔC_F per ITTC 1978 performance prediction - added to flat-plate C_F in ship extrapolation.
ΔC_F (ITTC 1978)
-0.04462 -
ΔC_F (common simple)
0.00040 -
Formula, assumptions, and limits
ITTC 1978 correlation. Smooth hull k_s ≈ 100 µm new build. Fouled hull can reach 300+ µm → ΔC_F nearly doubles. Driver for hull-cleaning ROI.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| Hull roughness | µm | BMT roughness gauge | |
| Waterline length | m | LWL |