Design Technology for Quiet UAV Propellers

"The coming generation of small, lightweight UAVs will require new quiet propeller designs to maximize acoustic stealth while building on off-the-shelf hardware and leveraging existing design technology to minimize cost. To meet an aggressive developmentschedule, it is necessary to exploit validated design analysis tools to minimize the expensive and time-consuming cut and try aspects of wind tunnel propeller testing. The proposed effort will build on the experience of a proven design team to develop aquiet UAV propeller that maintains high efficiency whilerealizing 12+ dB noise reductions. The effort will use established noise analysis tools to accelerate the design process as well as to allow the assessment of noise sources due to unsteady interactions not easily simulated in a wind tunnel environment.Phase I will also exploit recent insights into small scale (low Re) airfoil behavior as well as enhancements to established proprotor modeling and optimization software to support a wind tunnel testing effort that will be undertaken to validate thepredicted performance and noise levels. Following demonstration of promising designs, a manufacturing plan will be developed to ensure that cost and manufacturability targets can be met for production versions ofthe new propeller hardware. The recent rapid expansion of micro aircraft roles in defense applicationsis being mirrored by growth in possible civil roles for such concepts,includ