PROPELLER RPM INVESTIGATION FOR A LARGE HYDROFOIL CRAFT

摘要

A preliminary investigation of subcavitating, transcavitating, and supercavitating propellers was undertaken to determine the best reduction gear ratio for an 1100-ton hydrofoil. The results of this investigation indicate that a suitable pair of subcavitating, transcavitating, or supercavitating propellers can be designed for this craft if the propeller RPM lies between 550 and 700 RPM. Using one LM 2500 gas turbine engine per propeller and a 5:1 reduction between the turbine output and the propeller, a range of RPM's between 550 and 700 can be achieved by verying the maximum turbine RPM selected for the turbine at the full-power condition of 21,400 SHP. A propeller can be designed for the craft which will absorb this power anywhere between 550 and 700 propeller RPM.