Morphing wing has attracted many research attention and effort in aircraft technology development because of its advantage in lift to draft ratio and flight performance.Morphing wing technology combines the lift and c...Morphing wing has attracted many research attention and effort in aircraft technology development because of its advantage in lift to draft ratio and flight performance.Morphing wing technology combines the lift and control surfaces into a seamless wing and integrates the primary structure together with the internal control system.It makes use of the wing aeroelastic deformation induced by the control surface to gain direct force control through desirable redistribution of aerodynamic forces.However some unknown mechanical parameters of the control system and complexity of the integrated structure become a main challenge for dynamic modeling of morphing wing.To solve the problem,a method of test data based modal sensitivity analysis is presented to improve the morphing wing FE model by evaluating the unknown parameters and identifying the modeling boundary conditions.An innovative seamless morphing wing with the structure integrated with a flexible trailing edge control system is presented for the investigation.An experimental model of actuation system driven by a servo motor for the morphing wing is designed and established.By performing a vibration test and the proposed modal sensitivity analysis,the unknown torsional stiffness of the servo motor and the boundary condition of the actuation mechanism model is identified and evaluated.Comparing with the test data,the average error of the first four modal frequency of the improved FE model is reduced significantly to less than 4%.To further investigate the morphing wing modeling,a wing box and then a whole morphing wing model including the skin and integrated with the trailing edge actuation system are established and tested.By using the proposed method,the FE model is improved by relaxing the constraint between the skin and actuation mechanism.The results show that the average error of the first three modal frequency of the improved FE model is reduced to less than 6%.The research results demonstrate that the presented seamless morphing wing integrated with a flexible trailing edge control surface can improve aerodynamic characteristics.By using the test data based modal sensitivity analysis method,the unknown parameter and boundary condition of the actuation model can be determined to improve the FE model.The problem in dynamic modeling of high accuracy for a morphing wing can be solved in an effective manner.展开更多
We present a new multi-anticipation lattice hydrodynamic model based on the traffic anticipation effect in the real world. Applying the linear stability theory, we obtain the linear stability condition of the model. T...We present a new multi-anticipation lattice hydrodynamic model based on the traffic anticipation effect in the real world. Applying the linear stability theory, we obtain the linear stability condition of the model. Through nonlinear analysis, we derive the modified Korteweg-de Vries equation to describe the propagating behaviour of a traffic density wave near the critical point. The good agreement between the simulation results and the analytical results shows that the stability of traffic flow can be enhanced when the multi^anticipation effect is considered.展开更多
Based on the further analysis of trail's concept,trail tourist attractions was proposed as a new concept,and the 5-dimension(trail resource,trail operation,trail technology,trail management and trail economic inde...Based on the further analysis of trail's concept,trail tourist attractions was proposed as a new concept,and the 5-dimension(trail resource,trail operation,trail technology,trail management and trail economic index) theoretical assessment framework for trail tourist attractions was established. Trail route selection,trail pavement and trail management grade were taken for example to explain the specifications for these secondary indexes. The future research should expand the index system to cover all secondary indexes of the 5 dimensions,put the concept of trail tourist attractions into tourism planning practices,and provide examples for the construction of trail tourist attractions across the country. Proposal of the concept of trail tourist attractions and its assessment standards is an attempt and innovation in the development of scenic areas,and will possibly result in the new development rules of scenic areas.展开更多
基金supported by National Natural Science Foundation of China (Grant No. 11102019)
文摘Morphing wing has attracted many research attention and effort in aircraft technology development because of its advantage in lift to draft ratio and flight performance.Morphing wing technology combines the lift and control surfaces into a seamless wing and integrates the primary structure together with the internal control system.It makes use of the wing aeroelastic deformation induced by the control surface to gain direct force control through desirable redistribution of aerodynamic forces.However some unknown mechanical parameters of the control system and complexity of the integrated structure become a main challenge for dynamic modeling of morphing wing.To solve the problem,a method of test data based modal sensitivity analysis is presented to improve the morphing wing FE model by evaluating the unknown parameters and identifying the modeling boundary conditions.An innovative seamless morphing wing with the structure integrated with a flexible trailing edge control system is presented for the investigation.An experimental model of actuation system driven by a servo motor for the morphing wing is designed and established.By performing a vibration test and the proposed modal sensitivity analysis,the unknown torsional stiffness of the servo motor and the boundary condition of the actuation mechanism model is identified and evaluated.Comparing with the test data,the average error of the first four modal frequency of the improved FE model is reduced significantly to less than 4%.To further investigate the morphing wing modeling,a wing box and then a whole morphing wing model including the skin and integrated with the trailing edge actuation system are established and tested.By using the proposed method,the FE model is improved by relaxing the constraint between the skin and actuation mechanism.The results show that the average error of the first three modal frequency of the improved FE model is reduced to less than 6%.The research results demonstrate that the presented seamless morphing wing integrated with a flexible trailing edge control surface can improve aerodynamic characteristics.By using the test data based modal sensitivity analysis method,the unknown parameter and boundary condition of the actuation model can be determined to improve the FE model.The problem in dynamic modeling of high accuracy for a morphing wing can be solved in an effective manner.
基金Project supported by the National High Technology and Development Program of China (Grant No. 511-0910-1031)Doctoral Fund of Ministry of Education of China (Grant No. 20090191110022)
文摘We present a new multi-anticipation lattice hydrodynamic model based on the traffic anticipation effect in the real world. Applying the linear stability theory, we obtain the linear stability condition of the model. Through nonlinear analysis, we derive the modified Korteweg-de Vries equation to describe the propagating behaviour of a traffic density wave near the critical point. The good agreement between the simulation results and the analytical results shows that the stability of traffic flow can be enhanced when the multi^anticipation effect is considered.
基金Sponsored by "Twelfth Five-year Plan" Program of Guangdong Provincial Philosophy and Social Sciences(GD15XLS07)
文摘Based on the further analysis of trail's concept,trail tourist attractions was proposed as a new concept,and the 5-dimension(trail resource,trail operation,trail technology,trail management and trail economic index) theoretical assessment framework for trail tourist attractions was established. Trail route selection,trail pavement and trail management grade were taken for example to explain the specifications for these secondary indexes. The future research should expand the index system to cover all secondary indexes of the 5 dimensions,put the concept of trail tourist attractions into tourism planning practices,and provide examples for the construction of trail tourist attractions across the country. Proposal of the concept of trail tourist attractions and its assessment standards is an attempt and innovation in the development of scenic areas,and will possibly result in the new development rules of scenic areas.
