To reduce the pitch link loads of variable speed rotors, variable tuning frequency fluid- lastic isolators are proposed. This isolator utilizes the variation of centrifugal force due to the change of rotor speed to ch...To reduce the pitch link loads of variable speed rotors, variable tuning frequency fluid- lastic isolators are proposed. This isolator utilizes the variation of centrifugal force due to the change of rotor speed to change the tuning port area ratio, which can change the tuning frequency of the isolator. A rotor model including the model of fluidlastic isolator is coupled with a fuselage model to predict the steady responses of the rotor system in forward flight. The aeroelastic analyses indicate that distinct performance improvement in pitch link load control can be achieved by the utilization of variable frequency isolators compared with the constant tuning frequency isolators. The 4/rev （per revolution） pitch link load is observed to be reduced by 87.6% compared with the increase of 56.3% by the constant frequency isolator, when the rotor speed is reduced by 16.7%. The isolation ability at different rotor speeds in different flight states is investigated. To achieve overall load reduction within the whole range of rotor speed, the strategy of the variation of tuning frequency is adjusted. The results indicate that the 4/rev pitch link load within the whole rotor speed range is decreased.展开更多
随着物联网与互联网融合的不断深化,感知层与应用层之间的互联互通要求不断提高。针对现有数据采集系统存在的规范性、扩展性和适应性不足的问题,文章提出一套基于对象连接与嵌入过程控制统一架构(object linking and embedding for pro...随着物联网与互联网融合的不断深化,感知层与应用层之间的互联互通要求不断提高。针对现有数据采集系统存在的规范性、扩展性和适应性不足的问题,文章提出一套基于对象连接与嵌入过程控制统一架构(object linking and embedding for process control unified architecture,OPC UA)协议的分布式数据采集处理系统架构。对数据采集处理系统各个模块进行功能解耦和架构重组,分别介绍该系统硬件和软件架构;针对发布订阅模式下负载的特异性,提出一种改进的适用于OPC UA分布式订阅的负载均衡算法;最后在某车企实例验证该系统架构。结果表明,基于OPC UA的分布式数据采集处理系统数据采集处理效果良好,证明了该系统架构的可行性及有效性。展开更多
基金co-supported by the National Natural Science Foundation of China (Nos. 11202097 and 11472129)Aeronautical Science Foundation of China (No. 2013ZA52014)the Fundamental Research Funds for the Central Universities (No. NS2014007)
文摘To reduce the pitch link loads of variable speed rotors, variable tuning frequency fluid- lastic isolators are proposed. This isolator utilizes the variation of centrifugal force due to the change of rotor speed to change the tuning port area ratio, which can change the tuning frequency of the isolator. A rotor model including the model of fluidlastic isolator is coupled with a fuselage model to predict the steady responses of the rotor system in forward flight. The aeroelastic analyses indicate that distinct performance improvement in pitch link load control can be achieved by the utilization of variable frequency isolators compared with the constant tuning frequency isolators. The 4/rev （per revolution） pitch link load is observed to be reduced by 87.6% compared with the increase of 56.3% by the constant frequency isolator, when the rotor speed is reduced by 16.7%. The isolation ability at different rotor speeds in different flight states is investigated. To achieve overall load reduction within the whole range of rotor speed, the strategy of the variation of tuning frequency is adjusted. The results indicate that the 4/rev pitch link load within the whole rotor speed range is decreased.
文摘随着物联网与互联网融合的不断深化,感知层与应用层之间的互联互通要求不断提高。针对现有数据采集系统存在的规范性、扩展性和适应性不足的问题,文章提出一套基于对象连接与嵌入过程控制统一架构(object linking and embedding for process control unified architecture,OPC UA)协议的分布式数据采集处理系统架构。对数据采集处理系统各个模块进行功能解耦和架构重组,分别介绍该系统硬件和软件架构;针对发布订阅模式下负载的特异性,提出一种改进的适用于OPC UA分布式订阅的负载均衡算法;最后在某车企实例验证该系统架构。结果表明,基于OPC UA的分布式数据采集处理系统数据采集处理效果良好,证明了该系统架构的可行性及有效性。
基金This work was supported by the National Natural Science Foundation of China （No. 70674108/60703118） and the Natural Science Foundation of Shaanxi （No. 2007A01）.
