Propeller - Advance Coefficient J
Propeller advance coefficient J = V_A / (n·D) - the dimensionless speed on open-water characteristics.
Advance velocity V_A
5.04m/s
Advance coefficient
0.444 -
Formula, assumptions, and limits
Design J typically 0.4–0.8 for merchant propellers. Higher J = lighter loading; lower J = heavier. Match J to design KT/KQ point on open-water chart.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| Advance velocity | m/s | V_S (1-w) | |
| Propeller revolutions | rev/s | shaft rpm ÷ 60 | |
| Propeller diameter | m | prop geometry |