The need for quieting the propulsion system of naval vessels is identified Quiet turning capability and non-rotating propulsion systems are two concepts that can be employed to increase the stealthiness of ships, without the associated loss of propulsive performance. By using propellers running in variable-geometry shrouds, thrust vectoring can be achieved, in lieu of using a rudder or turning the shroud. It is also possible to create a non- rotating propulsion system that uses variable geometry to impart energy to a flow, providing propulsive power for the vessel. Both these proposed concepts utilize smart materials to effect the desired shape change. Aerotech proposes to develop two smart materials-based systems for enhancing the stealth performance of Navy ship propulsion systems: the first is a variable geometry shroud for thrust vectoring, and the second is a propulsion system that uses variable geometry to effect propulsion. The use of smart materials such as magnetostrictives and piezoelectrics offers unique advantages to designers and operators of engineering systems. Such systems can produce
Benefit: Actuators developed for these applications can be inserted into actuation systems used in medical, aerospace, automotive, industrial motion, optics and other fields.
Keywords: rudder, rudder, thrust vectoring, quiet turning, Noise, stealth, magnetostrictive actuator, shrouded propeller, cavitation
