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Rotor noise and vibration are two sources of operational challenges for all aircraft operating with open rotors such as helicopters, unmanned aerial vehicles (UAVs), urban air mobility personal air vehicles, drones, and aircraft operating with ducted fans such as passenger aircraft. One disadvantage of convention rotor design is the noise due to noise-induced shed vortices generated by rotor blades. The unique problem with rotor noise and vibration is the periodic blade passage that causes a harmonic reinforcement and causes the rotor blades to vibrate and generate noise sources. This technology from NASA Ames seeks to optimize the implementation of anti-phase trailing edge designs and asymmetric blade tip treatments for rotor noise suppression and integrated aircraft noise solutions by incorporating the anti-phase rotor design concepts into an aircraft flight control system to reduce noise footprint. There are several embodiments of the invention, which include the following: (1) an anti-phase trailing edge design whereby the trailing edge pattern of the leading rotor blade is offset by a phase shift from the trailing edge pattern of the following blade; (2) an anti-phase rotor design implementing asymmetric blade tips with inverted airfoil; and (3) other anti-phase enabled concepts such as unequal blade length, ducted rotors with non-radial unequally spaced struts, and multi-axis tilt rotor design incorporating the anti-phase rotor design.

This invention, developed under the Rotor Optimization for the Advancement of Mars eXploration (ROAMX) project, provides a method for optimizing airfoil geometries for aerial flight vehicles generally, and can also specifically optimize airfoil geometries for operating in Martian or other low Reynolds number environments. The method introduces a new “ROAMX parameterization” that defines geometric constraints, such as camber node count and the number and order of Bézier curve segments, to generate candidate airfoil shapes. A genetic algorithm evaluates these shapes against multiple objectives and iteratively selects the best-performing designs, converging on a Pareto-optimal front. This enables simultaneous optimization of metrics such as maximizing lift and minimizing drag. Using the ROAMX 1301 parameterization, the method produced an airfoil with lift to drag ratio improvements of up to 42% over the outboard airfoil used on the Mars Helicopter Ingenuity, representing a significant performance gain.