Injection-Molded Contrarotating Composite Propellers for Torpedo and UUV Applications

While toroidal propellers present an opportunity to reduce operational noise by minimizing vortex formation at the propeller tips, their designs are nearly impossible to mass manufacture, with high molding costs and labor-intensive processes that are cost prohibitive. In lieu of offering a high-risk work plan to achieve a toroidal propeller design that may or may not achieve the manufacturing and performance specifications listed in the topic, American Maglev Technology of Florida (AMT)Ýis uniquely qualified to offer a much lower-risk and recently proven alternative approach, with an opportunity to yield a radically lower acquisition cost and greater value to the Navy.ÝThe approach was developed and refined in a recent Defense Logistics Agency (DLA) SBIR program where AMT led the reverse engineering of contrarotating composite torpedo propellers using injection-molded fabrication of a qualified resin material, resulting in what is understood to be much improved performance and 55% cost savings per set. This new Phase I program will optimize AMTís design to meet the defined system capabilities in fuel efficiency, top speed, and transmission of noise to environment as listed in the topic. Like the Mk54 LWT Design of Record propellers, AMT propellers utilize a torque-balanced inner/outer shaft design to propel the torpedo and are constrained to counter-rotating operation and aluminum shaft-driven layouts that would be a direct drop-in replacement for DOR propellers. ÝÝAMTís prior work informs us that the major opportunity to radically reduce propeller cost without sacrificing quality and performance is by means of manufacture using proven and mature injection-molding technology. Injection molding also allows for high-confidence, predictable fiber orientation that can be easily repeatable.ÝInjection molding is a well-established, enabling technology that opens the door to high production runs and significant cost savings for this critical defense product.ÝÝThis head-start should contribute to AMTís high probability of success in this venture. ÝIn all cases, design efforts will be governed by AMTís ability to execute the design as an injection-molded part with an aluminum core and spline that is exactly as the current DOR. The design improvements resulting from this project, if successful, have the potential to obsolete propeller design for torpedoes, UUVs, and other watercraft for defense and commercial applications and markets.