Biology-Inspired Propulsion

"Physical Sciences Inc. (PSI) proposes to develop marine propulsion concepts that employ biologically inspired aerodynamic mechanisms to enhance propulsor thrust and decrease the propeller rotation rate necessary to maintain a specified forward speed.Flying animals take advantage of three unsteady aerodynamic mechanisms to generate lift and propulsive power greater than that predicted from quasi-steady conventional airfoil theory. The three mechanisms are delayed stall, rotational circulation(including the clap and fling mechanism), and wake capture. In Phase I we will formulate three propulsion concepts, each incorporating one or more biomimetic unsteady aerodynamic mechanisms. Using phenomenological models and experimental data fromliterature, the concepts will be evaluated for lift production, efficiency, simplicity, and ease of practical implementation. Key physical and non-dimensional flow parameters will be identified for each concept. The most promising propulsion concept willbe experimentally investigated in the PSI low speed wind tunnel to understand unsteady flow mechanisms. Phase I will conclude with a recommendation of which of the proposed designs, or modified designs, should be further studied in Phase II. In Phase IIvarious models of promising concepts will be fabricated and the propulsive forces produced by these models will be measured in a wind or water tunnel. The proposed propulsion concept will allow milita