Biomimetic Underwater Propulsion System Using Hybrid Synthetic Muscles

Currently, surface ship or underwater vehicle propulsors have fixed blade geometries. This introduces limitations, which are common in most passive control/geometry systems, when compared to active control/geometry systems. A typical limitation, forexample, is the performance degradation suffered by passive systems at off-design conditions. An opportunity therefore arises to develop active propulsor geometry reconfiguration technologies towards enhancing the propulsor''s cavitation performance, toproduce vectored and/or reversing thrust, to reduce wake and reducing/altering acoustic signatures of military ships. Current technologies for addressing these issues either do not exist or use exotic mechanical systems that are heavy, complex and costly.Having a propeller that can optimize its loading at any given speed and depth could save millions of barrels of fuel every year while providing improved stealth features. Compact muscles/actuators will be designed to simultaneously achieve high stroke,force and power density values. These muscles will be incorporated in the blades of a typical propulsor in order to achieve active blade geometry reconfiguration, with emphasis on cambering, with the objective of enhancing the propulsor?s hydrodynamicperformance, especially at off-design conditions, and reducing the necessary rotational speed thus leading to acoustic noise reduction. The proposed innovation will find potential applications in the design of high performance, low noise helicopter blades,propellers, turbomachines, keel and rudder of racing sail boats and other marine vehicles, pumps, etc.