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Derived from a design approach for a new wing known as PRANDTL-D, this technology achieves similar improvements for propellers and other rotating machinery. <b><em>How It Works</b></em> To achieve the innovation's alternate spanload, Armstrong designers applied a non-linear twist to the propeller blade. The twist moves the load inward and dissipates the tip vortex over a wider area, minimizing its effect on drag. It also results in a decrease in load at the tip and reduced torque at the tip. These changes combine to achieve a dramatic reduction in power consumption without compromising the blade's other parameters. Specifically, the blade's diameter and rpm remain unchanged. <b><em>What Makes It Better</b></em> Unlike the conventional minimum induced loss (elliptical) spanload, which consumes large amounts of power at the tip of the blade, the new design unloads the tip and reduces torque, achieving significant improvements in efficiency. First-order analysis shows a more than 15 percent improvement in power consumption while producing the same thrust. The design also produces significantly less noise than conventional blade designs.

The Active Turbulence Suppression (ATS) system for electric Vertical Take-Off and Landing (eVTOL) vehicles employ existing lifting propellers to dampen instabilities during flight, such as Dutch-roll oscillations and other gust-induced oscillations. When a roll angle of an eVTOL aircraft has deviated or is about to deviate from a current stable aircraft state to an undesirable, unstable, and oscillating aircraft state, the ATS system queries a turbulence suppression database that stores a set of propeller speed profiles for mitigation a deviation of a given roll angle for a particular aircraft with specified propellers. Using this data, the eVTOL flight controller adjusts the speed of the propellers for a certain duration of time, according to the propeller speed profiles for mitigating the deviation. In models of aircraft with adjustable propeller angles, the database includes blade angle profiles for mitigating the effects of turbulent conditions. Timing and rate of propeller activation can be pre-computed using higher order computational modeling performed with NASA’s super computing resources. Because the data is pre-computed, the use of the ATS system onboard does not require significant computing resources to implement on eVTOL vehicles. The technology, a mechanism by which existing eVTOL propellers are leveraged to suppress gust-induced oscillations enables a safe and comfortable passenger experience at low-cost and without added hardware.