针对出行即服务(Mobility as a Service,MaaS)提供定制化的出行服务以满足游客差异化的交通需求,构建了由传统旅游供应商和MaaS平台组成的双渠道旅游出行服务链,探讨不同主导权下的集中式决策和分散式决策策略及其效益,并开展以供应商...针对出行即服务(Mobility as a Service,MaaS)提供定制化的出行服务以满足游客差异化的交通需求,构建了由传统旅游供应商和MaaS平台组成的双渠道旅游出行服务链,探讨不同主导权下的集中式决策和分散式决策策略及其效益,并开展以供应商为主导的供应链收益共享契约设计和数值分析。研究结果发现:基于MaaS的旅游供应链集中式决策下的效益大于分散式决策,且集中式决策效益是以供应商为主导的分散式决策效益的3/4。在收益共享契约协调下,供应商利润和MaaS平台利润分别为0.68和0.58,均有所提高,旅游供应链整体效益最大,实现旅游供应链完美协调。展开更多
Blade rubbing faults cause detrimental impact on the operation of aeroengines. Most of the existing studies on blade rubbing in the shaft-disk-blade-casing(SDBC) system have overlooked the elastic deformation of the b...Blade rubbing faults cause detrimental impact on the operation of aeroengines. Most of the existing studies on blade rubbing in the shaft-disk-blade-casing(SDBC) system have overlooked the elastic deformation of the blade, while some only consider the whirl of the rotor, neglecting its spin. To address these limitations, this paper proposes a dynamic model with large rotation for the SDBC system. The model incorporates the spin and whirl of the rotor, enabling the realistic reproduction of multiblade rubbing faults. To verify the accuracy of the SDBC model with large rotation and demonstrate its capability to effectively consider the rotational effects such as the centrifugal stiffening and gyroscopic effects, the natural characteristics and dynamic responses of the proposed model are compared with those obtained from reported research and experimental results. Furthermore, the effects of the rotating speed, contact stiffness,and blade number on the dynamic characteristics of the SDBC system with multi-blade rubbing are investigated. The results indicate that the phase angle between the rotor deflection and the unbalance excitation force increases with the increasing rotating speed,which significantly influences the rubbing penetration of each blade. The natural frequency of the SDBC system with rubbing constrain can be observed in the acceleration response of the casing and the torsional response of the shaft, and the frequency is related to the contact stiffness. Moreover, the vibration amplitude increases significantly with the product of the blade number under rubbing, and the rotating frequency approaches the natural frequency of the SDBC system. The proposed model can provide valuable insight for the fault diagnosis of rubbing in bladed rotating machinery.展开更多
文摘针对出行即服务(Mobility as a Service,MaaS)提供定制化的出行服务以满足游客差异化的交通需求,构建了由传统旅游供应商和MaaS平台组成的双渠道旅游出行服务链,探讨不同主导权下的集中式决策和分散式决策策略及其效益,并开展以供应商为主导的供应链收益共享契约设计和数值分析。研究结果发现:基于MaaS的旅游供应链集中式决策下的效益大于分散式决策,且集中式决策效益是以供应商为主导的分散式决策效益的3/4。在收益共享契约协调下,供应商利润和MaaS平台利润分别为0.68和0.58,均有所提高,旅游供应链整体效益最大,实现旅游供应链完美协调。
基金Project supported by the National Science and Technology Major Project of China (No. 2017-V-0009)the National Natural Science Foundation of China (Nos. 12032015 and 12121002)the National Funding Program for Postdoctoral Researchers of China (No. GZC20231586)。
文摘Blade rubbing faults cause detrimental impact on the operation of aeroengines. Most of the existing studies on blade rubbing in the shaft-disk-blade-casing(SDBC) system have overlooked the elastic deformation of the blade, while some only consider the whirl of the rotor, neglecting its spin. To address these limitations, this paper proposes a dynamic model with large rotation for the SDBC system. The model incorporates the spin and whirl of the rotor, enabling the realistic reproduction of multiblade rubbing faults. To verify the accuracy of the SDBC model with large rotation and demonstrate its capability to effectively consider the rotational effects such as the centrifugal stiffening and gyroscopic effects, the natural characteristics and dynamic responses of the proposed model are compared with those obtained from reported research and experimental results. Furthermore, the effects of the rotating speed, contact stiffness,and blade number on the dynamic characteristics of the SDBC system with multi-blade rubbing are investigated. The results indicate that the phase angle between the rotor deflection and the unbalance excitation force increases with the increasing rotating speed,which significantly influences the rubbing penetration of each blade. The natural frequency of the SDBC system with rubbing constrain can be observed in the acceleration response of the casing and the torsional response of the shaft, and the frequency is related to the contact stiffness. Moreover, the vibration amplitude increases significantly with the product of the blade number under rubbing, and the rotating frequency approaches the natural frequency of the SDBC system. The proposed model can provide valuable insight for the fault diagnosis of rubbing in bladed rotating machinery.
