It can be greatly beneficial to remove the swashplate of conventional helicopter, because the swashplate is usually complicated, aerodynamically resistive, and obstacle of more complex pitch control for improving perf...It can be greatly beneficial to remove the swashplate of conventional helicopter, because the swashplate is usually complicated, aerodynamically resistive, and obstacle of more complex pitch control for improving performance. The present technologies for helicopter vibration reduction are usually narrow in effective range or requiring additional actuators and signal transfer links, and more effective technology is desired. Helicopter blade pitch control system, which is removed of swashplate and integrated high-frequency pitch control function for active vibration reduction, is likely the suitable solution at current technical level. Several potential implementation schemes are discussed, such as blades being directly or indirectly driven by actuators mounted in rotating frame and application of different types of actuators, especially implementation schemes of electro-mechanical actuator with or without gear reducer. It is found that swashplateless blade pitch control system based on specially designed limited angle direct-drive motor （LADDM） is a more practical implementation scheme. An experimental prototype of the finally selected implementation scheme has been designed, fabricated and tested on rotor tower. The test results show considerable feasibility of the swashplateless helicopter blade pitch control system using the LADDM.展开更多
风力机轮毂直径加大之后,可以加大风轮直径,从而使风力机的额定功率明显提高,同时轮毂的受力情况也大大改善,是一种具有实际应用价值的设计方法。但这种方法的缺点是起动性能及低风速下的功率输出往往变差。因此,深入分析和优化轮毂尺...风力机轮毂直径加大之后,可以加大风轮直径,从而使风力机的额定功率明显提高,同时轮毂的受力情况也大大改善,是一种具有实际应用价值的设计方法。但这种方法的缺点是起动性能及低风速下的功率输出往往变差。因此,深入分析和优化轮毂尺寸调整后风力机的起动性能及低风速性能,是应用这一方法的必要环节。笔者着重分析定转速失速型风力机的气动性能及低风速性能与轮毂直径之间的关系,从理论上找出这种风力机起动性能和低风速性能变差的原因,并提出调整桨叶安装角和风轮转速两种低风速性能优化方法。应用风力机设计软件Blade for Windows对设计实例进行计算,对以上结论和解决方法进行了验证。展开更多
文摘It can be greatly beneficial to remove the swashplate of conventional helicopter, because the swashplate is usually complicated, aerodynamically resistive, and obstacle of more complex pitch control for improving performance. The present technologies for helicopter vibration reduction are usually narrow in effective range or requiring additional actuators and signal transfer links, and more effective technology is desired. Helicopter blade pitch control system, which is removed of swashplate and integrated high-frequency pitch control function for active vibration reduction, is likely the suitable solution at current technical level. Several potential implementation schemes are discussed, such as blades being directly or indirectly driven by actuators mounted in rotating frame and application of different types of actuators, especially implementation schemes of electro-mechanical actuator with or without gear reducer. It is found that swashplateless blade pitch control system based on specially designed limited angle direct-drive motor （LADDM） is a more practical implementation scheme. An experimental prototype of the finally selected implementation scheme has been designed, fabricated and tested on rotor tower. The test results show considerable feasibility of the swashplateless helicopter blade pitch control system using the LADDM.
文摘风力机轮毂直径加大之后,可以加大风轮直径,从而使风力机的额定功率明显提高,同时轮毂的受力情况也大大改善,是一种具有实际应用价值的设计方法。但这种方法的缺点是起动性能及低风速下的功率输出往往变差。因此,深入分析和优化轮毂尺寸调整后风力机的起动性能及低风速性能,是应用这一方法的必要环节。笔者着重分析定转速失速型风力机的气动性能及低风速性能与轮毂直径之间的关系,从理论上找出这种风力机起动性能和低风速性能变差的原因,并提出调整桨叶安装角和风轮转速两种低风速性能优化方法。应用风力机设计软件Blade for Windows对设计实例进行计算,对以上结论和解决方法进行了验证。
