Breakthrough rotor model enables safe transitions for aerial-aquatic vehicles
Peer-Reviewed Publication
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Updates every hour. Last Updated: 23-Jul-2025 08:12 ET (23-Jul-2025 12:12 GMT/UTC)
Operating drones across air and water boundaries poses serious aerodynamic risks due to complex gas-liquid flow interactions. A new finite vortex rotor model developed by researchers in China provides unprecedented insight into how rotors behave near free water surface. The study introduces a predictive boundary that separates safe and unsafe flight zones, offering a powerful tool for the design and control of aerial-aquatic rotorcraft.
To reduce the vibration of the coaxial helicopter main transmission system considering both level and vertical flight conditions, a vibration evaluation and optimization model was built. A vibration simulation model and a vibration evaluation method was established. A hybrid Gravitational Search Algorithm-Simulated Annealing (GSA-SA) algorithm was combined to balance convergence speed and searching accuracy. The principle test was conducted to prove the accuracy of theoretical method. The optional results show that the vibration of the optimized transmission system decreases significantly, in which the maximum reduction of key vibration indicators reaches more than 20%. The proposed method could be extended to other fields.
Propeller-driven aircraft are gaining renewed attention for sustainable aviation. Yet balancing efficiency with noise reduction remains a critical challenge—especially for emerging platforms such as eVTOL and hybrid-electric aircraft. Researchers from Nanjing University of Aeronautics and Astronautics have developed a new optimization framework based on the unsteady adjoint method that successfully addresses this trade-off. Their work offers a powerful tool for designing quieter, more efficient propellers, paving the way for the next generation of low-emission, low-noise aviation.
Aero-engine hot-end components face grinding challenges due to superalloys' low thermal conductivity, causing high heat, energy consumption, and reliance on unsustainable cooling. Ultrasonic vibration-assisted grinding (UVAG), heat pipe grinding wheels (HPGW), and minimum quantity lubrication (MQL) have been proposed to integrate to reduce heat generation, enhance heat dissipation, and minimize coolant use. In this case, the high-efficiency and sustainable grinding can be achieved with improved surface integrity.