This paper presents a global methodology to compute wind flow in complex urban areas in order to assess wind pedestrian comfort, wind energy, wind safety or natural ventilation potential. The numerical tool presented ...This paper presents a global methodology to compute wind flow in complex urban areas in order to assess wind pedestrian comfort, wind energy, wind safety or natural ventilation potential. The numerical tool presented here is composed of a CFD soft-ware suite covering both regional scale (20 km) and urban scale (1km), and able to model the wind in any complex terrains and in large urban environments. Examples are presented in the paper in order to show the advantages of the methodology for urban designers.展开更多
Wind engineering has made significant strides in addressing the challenges posed by exceptional terrains,where traditional methodologies often fall short.This paper reviews the advances in wind tunnel technology and c...Wind engineering has made significant strides in addressing the challenges posed by exceptional terrains,where traditional methodologies often fall short.This paper reviews the advances in wind tunnel technology and computational fluid dynamics(CFD)that have revolutionized the understanding and prediction of wind effects on bridges,particularly in complex environments.The integration of advanced measurement techniques with wind tunnel experiments has provided deeper insights into wind characteristics,leading to more accurate aerodynamic designs for bridges.The application of these technologies in unique terrains has been instrumental in ensuring the safety and stability of critical infrastructures.The paper reviews the importance of continuous research and collaboration in wind engineering to address the evolving demands of infrastructure in challenging terrains.The article also introduces the wind tunnel facilities at Chang'an University,detailing their capabilities and contributions to research in wind engineering,including the study of aerodynamic performance and control measures for bridges.It is concluded by reflecting on the research team's 20-year journey at Chang'an University,noting their growth,achievements,and contributions to the field of wind engineering.展开更多
An application of recent uncertainty quantification techniques to Wind Engineering is presented.In particular,the study of the effects of small geometric changes in the Sunshine Skyway Bridge deck on its aerodynamic b...An application of recent uncertainty quantification techniques to Wind Engineering is presented.In particular,the study of the effects of small geometric changes in the Sunshine Skyway Bridge deck on its aerodynamic behavior is addressed.This results in the numerical solution of a proper PDE posed in a domain affected by randomness,which is handled through a mapping approach.A non-intrusive Polynomial Chaos expansion allows to transform the stochastic problem into a deterministic one,in which a commercial code is used as a black-box for the solution of a number of Reynolds-Averaged Navier-Stokes simulations.The use of proper Gauss-Patterson nested quadrature formulas with respect to a Truncated Weibull probability density function permits to limit the number of these computationally expensive simulations,though maintaining a sufficient accuracy.Polynomial Chaos approximations,statistical moments and probability density functions of time-independent quantities of interest for the engineering applications are obtained.展开更多
Nanogenerator technologies have gained significant attention as sustainable methods for harvesting energy and powering various applications.We review the research progress and obstacles related to triboelectric and pi...Nanogenerator technologies have gained significant attention as sustainable methods for harvesting energy and powering various applications.We review the research progress and obstacles related to triboelectric and piezoelectric nanogenerators utilized for wind energy extraction.This is crucial given the increasing demand for clean energy sources and the importance of technologies that can efficiently harvest such energy.We highlight the role of triboelectric and piezoelectric nanogenerators as promising solutions for capturing mechanical energy from wind sources.First,the fundamental physics modes of triboelectric and piezoelectric nanogenerators are discussed.The mechanisms underlying the triboelectric effect and the piezoelectric effect are explained,emphasizing their relevance to energy harvesting applications.An overview of energy harvesting using triboelectric and piezoelectric nanogenerators is then provided,encompassing the latest developments in the field.This review encompasses the design principles,materials,and fabrication techniques employed in the construction of triboelectric and piezoelectric nanogenerators.Specifically,we delve into how nanogenerators are utilized for wind energy harvesting.Various approaches for optimizing the performance of these devices are examined,along with methods of integration into wind energy harvesting systems.The potential applications of these devices are highlighted,along with the challenges that may come with their implementation.We conclude by discussing the current state of research,future perspectives,and insights into wind energy harvesting using triboelectric and piezoelectric nanogenerators.Accordingly,we recommend that future research addresses issues such as scalability,durability,and system integration.This review provides a comprehensive analysis of the use of triboelectric and piezoelectric nanogenerators for wind energy harvesting.It serves as a reference for researchers and engineers working in wind engineering,offering insights and directions for future advancements.展开更多
This paper reviews the development of forced motion apparatuses(FMAs) and their applications in wind engineering. A kind of FMA has been developed to investigate nonlinear and nonstationary aerodynamic forces consider...This paper reviews the development of forced motion apparatuses(FMAs) and their applications in wind engineering. A kind of FMA has been developed to investigate nonlinear and nonstationary aerodynamic forces considering the coupled effects of multiple degrees of freedom(DOFs). This apparatus can make section models to vibrate in a prescribed displacement defined by a numerical signal in time domain, including stationary and nonstationary movements with time-variant amplitudes and frequencies and even stochastic displacements. A series of validation tests show that the apparatus can re-illustrate various motions with enough precision in 3 D coupled states of two linear displacements and one torsional displacement. To meet the requirement of aerodynamic modeling, the flutter derivatives of a box girder section are identified, verifying its accuracy and feasibility by comparing with previously reported results. By simulating the nonstationary vibration with time-variant amplitude, the phenomena of frequency multiplication and memory effects are examined. In addition to studying the aerodynamics of a bluff body under large amplitudes and nonstationary vibrations, some potential applications of the proposed FMA are discussed in vehicle-bridge-wind dynamic analysis, pile-soil interaction, and line-tower coupled vibration aerodynamics in structural engineering.展开更多
In recent years many long-span bridges have been or are being constructed in the world, especially in China. Wind loads and responses are the key factors for their structural design. This paper introduces some importa...In recent years many long-span bridges have been or are being constructed in the world, especially in China. Wind loads and responses are the key factors for their structural design. This paper introduces some important achievements of wind-resistant studies of the author's research team on long-span bridges. First, new concepts and identification methods of aerodynamic derivatives and aerodynamic admittances were proposed. Then mechanical and aerodynamic control strategies and methods of wind-induced vibrations of long-span bridges were the great concerned problems, and valuable achievements were presented. Especially, great efforts which have been theoretically and experimentally made on rain-wind induced vibration of cables of cable-stayed bridges were described. Finally, some new progresses in computation wind engineering were introduced, and a new method for simulating an equilibrium boundary layer was put forward as well.展开更多
文摘This paper presents a global methodology to compute wind flow in complex urban areas in order to assess wind pedestrian comfort, wind energy, wind safety or natural ventilation potential. The numerical tool presented here is composed of a CFD soft-ware suite covering both regional scale (20 km) and urban scale (1km), and able to model the wind in any complex terrains and in large urban environments. Examples are presented in the paper in order to show the advantages of the methodology for urban designers.
基金National Key R&D Program of China(No.2021YFB2600600)National Natural Science Foundation of China(No.51978077,52278478)Shaanxi Province Natural Science Foundation(No.2023-JCQN-0597,2023-JC-QN-0526,2023-JC-YB-408,2023-JC-YB-438,2022JM-198,2022JQ-507,2021JLM-47).
文摘Wind engineering has made significant strides in addressing the challenges posed by exceptional terrains,where traditional methodologies often fall short.This paper reviews the advances in wind tunnel technology and computational fluid dynamics(CFD)that have revolutionized the understanding and prediction of wind effects on bridges,particularly in complex environments.The integration of advanced measurement techniques with wind tunnel experiments has provided deeper insights into wind characteristics,leading to more accurate aerodynamic designs for bridges.The application of these technologies in unique terrains has been instrumental in ensuring the safety and stability of critical infrastructures.The paper reviews the importance of continuous research and collaboration in wind engineering to address the evolving demands of infrastructure in challenging terrains.The article also introduces the wind tunnel facilities at Chang'an University,detailing their capabilities and contributions to research in wind engineering,including the study of aerodynamic performance and control measures for bridges.It is concluded by reflecting on the research team's 20-year journey at Chang'an University,noting their growth,achievements,and contributions to the field of wind engineering.
基金The authors would like to thank Prof.L.Bruno(Politecnico di Torino)for his continuos support in understanding and simulating the physics of the aerodynamic phenomena discussed in the paperThe authors wish also to thank Prof.F.Ricciardelli(University of Reggio Calabria)and Dr.C.Mannini(University of Florence)for kindly providing the geometrical properties of the Sunshine Skyway Bridge and the wind-tunnel set-up dataFurther thanks go to Dr.S.Khris(Optiflow Company)and Prof.G.Monegato(Politecnico di Torino)for helpful discussions about the topics of the paper.
文摘An application of recent uncertainty quantification techniques to Wind Engineering is presented.In particular,the study of the effects of small geometric changes in the Sunshine Skyway Bridge deck on its aerodynamic behavior is addressed.This results in the numerical solution of a proper PDE posed in a domain affected by randomness,which is handled through a mapping approach.A non-intrusive Polynomial Chaos expansion allows to transform the stochastic problem into a deterministic one,in which a commercial code is used as a black-box for the solution of a number of Reynolds-Averaged Navier-Stokes simulations.The use of proper Gauss-Patterson nested quadrature formulas with respect to a Truncated Weibull probability density function permits to limit the number of these computationally expensive simulations,though maintaining a sufficient accuracy.Polynomial Chaos approximations,statistical moments and probability density functions of time-independent quantities of interest for the engineering applications are obtained.
文摘Nanogenerator technologies have gained significant attention as sustainable methods for harvesting energy and powering various applications.We review the research progress and obstacles related to triboelectric and piezoelectric nanogenerators utilized for wind energy extraction.This is crucial given the increasing demand for clean energy sources and the importance of technologies that can efficiently harvest such energy.We highlight the role of triboelectric and piezoelectric nanogenerators as promising solutions for capturing mechanical energy from wind sources.First,the fundamental physics modes of triboelectric and piezoelectric nanogenerators are discussed.The mechanisms underlying the triboelectric effect and the piezoelectric effect are explained,emphasizing their relevance to energy harvesting applications.An overview of energy harvesting using triboelectric and piezoelectric nanogenerators is then provided,encompassing the latest developments in the field.This review encompasses the design principles,materials,and fabrication techniques employed in the construction of triboelectric and piezoelectric nanogenerators.Specifically,we delve into how nanogenerators are utilized for wind energy harvesting.Various approaches for optimizing the performance of these devices are examined,along with methods of integration into wind energy harvesting systems.The potential applications of these devices are highlighted,along with the challenges that may come with their implementation.We conclude by discussing the current state of research,future perspectives,and insights into wind energy harvesting using triboelectric and piezoelectric nanogenerators.Accordingly,we recommend that future research addresses issues such as scalability,durability,and system integration.This review provides a comprehensive analysis of the use of triboelectric and piezoelectric nanogenerators for wind energy harvesting.It serves as a reference for researchers and engineers working in wind engineering,offering insights and directions for future advancements.
基金supported by the National Key Research and Development Program of China(Nos.2018YFC0809600 and 2018YFC0809604)the National Natural Science Foundation of China(No.51678451)the Independent Subject of State Key Laboratory of Disaster Reduction in Civil Engineering(No.SLDRCE19-B-11),Tongji University,China。
文摘This paper reviews the development of forced motion apparatuses(FMAs) and their applications in wind engineering. A kind of FMA has been developed to investigate nonlinear and nonstationary aerodynamic forces considering the coupled effects of multiple degrees of freedom(DOFs). This apparatus can make section models to vibrate in a prescribed displacement defined by a numerical signal in time domain, including stationary and nonstationary movements with time-variant amplitudes and frequencies and even stochastic displacements. A series of validation tests show that the apparatus can re-illustrate various motions with enough precision in 3 D coupled states of two linear displacements and one torsional displacement. To meet the requirement of aerodynamic modeling, the flutter derivatives of a box girder section are identified, verifying its accuracy and feasibility by comparing with previously reported results. By simulating the nonstationary vibration with time-variant amplitude, the phenomena of frequency multiplication and memory effects are examined. In addition to studying the aerodynamics of a bluff body under large amplitudes and nonstationary vibrations, some potential applications of the proposed FMA are discussed in vehicle-bridge-wind dynamic analysis, pile-soil interaction, and line-tower coupled vibration aerodynamics in structural engineering.
基金supported by the National Natural Science Foundation of China (Grant Nos. 59238161,59725818,50178049,50321803,and 50621062)
文摘In recent years many long-span bridges have been or are being constructed in the world, especially in China. Wind loads and responses are the key factors for their structural design. This paper introduces some important achievements of wind-resistant studies of the author's research team on long-span bridges. First, new concepts and identification methods of aerodynamic derivatives and aerodynamic admittances were proposed. Then mechanical and aerodynamic control strategies and methods of wind-induced vibrations of long-span bridges were the great concerned problems, and valuable achievements were presented. Especially, great efforts which have been theoretically and experimentally made on rain-wind induced vibration of cables of cable-stayed bridges were described. Finally, some new progresses in computation wind engineering were introduced, and a new method for simulating an equilibrium boundary layer was put forward as well.
