Form Factor (Prohaska)
Three-dimensional extrapolation form factor (1+k) derived from low-Fn resistance data - the ITTC-78 correction that separates frictional from residual resistance.
Form factor (1 + k)
0.952–
Formula, assumptions, and limits
Simplified Holtrop-style fit to a Prohaska-derived form factor. Typical merchants 1.15–1.30; fine-form containerships 1.10–1.20. Model-basin Prohaska plot of Ct/Cf vs Fn^4 gives the ship-specific value.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| Block coefficient | - | hydrostatics | |
| Beam-to-length ratio | - | particulars | |
| Draft-to-length ratio | - | particulars | |
| Form factor | - | result |