Morphing aircraft can adaptively regulate their aerodynamic layout to meet the demands of varying flight conditions,improve their aerodynamic efficiency,and reduce their energy consumption.The design and fabrication o...Morphing aircraft can adaptively regulate their aerodynamic layout to meet the demands of varying flight conditions,improve their aerodynamic efficiency,and reduce their energy consumption.The design and fabrication of high-performance,lightweight,and intelligent morphing structures have become a hot topic in advanced aircraft design.This paper discusses morphing aircraft development history,structural characteristics,existing applications,and future prospects.First,some conventional mechanical morphing aircraft are examined with focus on their morphing modes,mechanisms,advantages,and disadvantages.Second,the novel applications of several technologies for morphing unmanned aerial vehicles,including additive manufacturing for fabricating complex morphing structures,lattice technology for reducing structural weight,and multi-mode morphing combined with flexible skins and foldable structures,are summarized and categorized.Moreover,in consideration of the further development of active morphing aircraft,the paper reviews morphing structures driven by smart material actuators,such as shape memory alloy and macro-fiber composites,and analyzes their advantages and limitations.Third,the paper discusses multiple challenges,including flexible structures,flexible skins,and control systems,in the design of future morphing aircraft.Lastly,the development and application of morphing structures in the aerospace field are discussed to provide a reference for future research and engineering applications.展开更多
With the participation of large quantities of renewable energy in power system operations,their volatility and intermittence increases the difficulties and challenges of power system economic scheduling.Considering th...With the participation of large quantities of renewable energy in power system operations,their volatility and intermittence increases the difficulties and challenges of power system economic scheduling.Considering the uncertainty of renewable energy generation,based on the distributionally robust optimization method,a two-stage economic dispatch model is proposed to minimize the total operation costs.In this paper,it is assumed that the fluctuating of renewable power generation follows the unknown probability distribution that is restricted in an ambiguity set,which is established by utilizing the first-order moment information of available historical data.Furthermore,the theory of conditional value-at-risk is introduced to transform the model into a tractable model,which we call robust counterpart formulation.Based on the stochastic dual dynamic programming method,an improved iterative algorithm is proposed to solve the robust counterpart problem.Specifically,the convergence optimum can be obtained by the improved iterative algorithm,which performs a forward pass and backward pass repeatedly in each iterative process.Finally,by comparing with other methods,the results on the modified IEEE 6-bus,118-bus,and 300-bus system show the effectiveness and advantages of the proposed model and method.展开更多
基金supported by the Key Project of National Natural Science Foundation of China(Grant Nos.92271205,51790171,51735005,and 11620101002).
文摘Morphing aircraft can adaptively regulate their aerodynamic layout to meet the demands of varying flight conditions,improve their aerodynamic efficiency,and reduce their energy consumption.The design and fabrication of high-performance,lightweight,and intelligent morphing structures have become a hot topic in advanced aircraft design.This paper discusses morphing aircraft development history,structural characteristics,existing applications,and future prospects.First,some conventional mechanical morphing aircraft are examined with focus on their morphing modes,mechanisms,advantages,and disadvantages.Second,the novel applications of several technologies for morphing unmanned aerial vehicles,including additive manufacturing for fabricating complex morphing structures,lattice technology for reducing structural weight,and multi-mode morphing combined with flexible skins and foldable structures,are summarized and categorized.Moreover,in consideration of the further development of active morphing aircraft,the paper reviews morphing structures driven by smart material actuators,such as shape memory alloy and macro-fiber composites,and analyzes their advantages and limitations.Third,the paper discusses multiple challenges,including flexible structures,flexible skins,and control systems,in the design of future morphing aircraft.Lastly,the development and application of morphing structures in the aerospace field are discussed to provide a reference for future research and engineering applications.
基金supported by the National Natural Science Foundation of China(No.51777126)。
文摘With the participation of large quantities of renewable energy in power system operations,their volatility and intermittence increases the difficulties and challenges of power system economic scheduling.Considering the uncertainty of renewable energy generation,based on the distributionally robust optimization method,a two-stage economic dispatch model is proposed to minimize the total operation costs.In this paper,it is assumed that the fluctuating of renewable power generation follows the unknown probability distribution that is restricted in an ambiguity set,which is established by utilizing the first-order moment information of available historical data.Furthermore,the theory of conditional value-at-risk is introduced to transform the model into a tractable model,which we call robust counterpart formulation.Based on the stochastic dual dynamic programming method,an improved iterative algorithm is proposed to solve the robust counterpart problem.Specifically,the convergence optimum can be obtained by the improved iterative algorithm,which performs a forward pass and backward pass repeatedly in each iterative process.Finally,by comparing with other methods,the results on the modified IEEE 6-bus,118-bus,and 300-bus system show the effectiveness and advantages of the proposed model and method.
