Non-Abrasive Propeller Cleaning System (NAPCS) Navy SBIR FY2011.2 Sol No.: Navy SBIR FY2011.2 Topic No.: N112-157 Topic Title: Non-Abrasive Propeller Cleaning System (NAPCS) Proposal No.: N112-157-0347 Firm: Dynaflow, Inc. 10621-J Iron Bridge Rd. Jessup, Maryland 20794-9381 Contact: Georges Chahine Phone: (301) 604-3688 Web Site: www.dynaflow-inc.com Abstract: We propose to develop a propeller cleaning system using DYNAFLOW's advanced cavitating and resonating waterjet technology. This non-abrasive technology generates cavitating microstructures in the jet flow at low jet pressures, thus avoiding problems with high jet impact pressures. It utilizes acoustic resonance, jet structuring, and swirl flow generation to enhance the cavitation intensity. The resulting bubble and vortex clouds collapse over the fouling and remove it. The DYNAJETSr are effective at both very high and very low pump pressures depending on the fouling to remove. We propose to arrange the nozzles on rotating disks in an arrangement that allows self-induced disk rotation to increase coverage, simplify diver efforts, and clean the propeller surface efficiently and safely. A key strength of our approach is our fundamental and applied long term involvement with cavitation, erosion, and cavitating jet studies, which will enable us to develop an adaptable DYNAJETSr tool where the jet operation conditions can be tuned to the types of fouling to optimize cleaning operation efficiency while protecting the underlying propeller material surface. In Phase I, the feasibility of such a DYNAJETSr diver tool will be demonstrated, and the concept design will be developed through systematic experiments on fouled NAB plates. Benefits: The proposed fool will be a new generation of underwater cleaning tools that will achieve high cleaning efficiency without damaging the substrate material. It would replace current abrasive methods and enable improved cleaning effectiveness, full blade coverage, reduced diver fatigue, cleaning time, and risk of blade damage. This new diver tool should reduce overall cleaning time to less than half the current practice. The developed propeller cleaning system will be compact, energy efficient, and require low maintenance. The technology will also be expanded to commercial underwater cleaning tasks such as cleaning of ship hulls, marine structures, and other private sector industries including oil and gas, shipping, marine, and aquaculture industries. Return