Technology Trends for Naval Propulsion

This paper discusses trends in naval propulsion technology. While the most common type of propulsor – the screw propeller - has reached a high state of development, there are still improvements which can be made in ship propulsor systems which offer the expectation of modest gains in propulsive efficiency during the next 10 to 15 years. These improvements include better analytical tools; devices that recover the rotational energy in a propeller wake, such as contrarotating propellers, pre-swirl vanes, and vane wheels; devices that provide more uniform inflow conditions to the propeller, such as flow straightening vanes and nozzles; and hybrid combinations of propulsors which utilize each propulsor in its optimum operating range.