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The computational effort for wind turbine design loads calculations is more extreme than it is for other applications (e.g. aerospace) which necessitates the use of efficient but low-fidelity models. Traditionally the Blade Element Momentum (BEM) method is used to resolve the rotor aerodynamics loads for this purpose, as this method is fast and robust. With the current trend of increasing rotor size, and consequently large and flexible blades, a need has risen for a more accurate prediction of rotor aerodynamics. Previous work has demonstrated large improvement potential in terms of fatigue load predictions using vortex wake models together with a manageable penalty in computational effort. The present publication has contributed towards making vortex wake models ready for application to certification load calculations. The observed reduction in flapwise blade root moment fatigue loading using vortex wake models instead of the Blade Element Momentum method from previous publications has been verified using a numerical wind tunnel, i.e. Computational Fluid Dynamics (CFD) simulations. A validation effort against a long term field measurement campaign featuring 2.5 MW turbines has also confirmed the improved prediction of unsteady load characteristics by vortex wake models against BEM based models in terms of fatigue loading. New light has been shed on the cause for the observed differences and several model improvements have been developed, both to reduce the computational effort of vortex wake simulations and to make BEM models more accurate. Scoping analyses for an entire fatigue load set have revealed the overall fatigue reduction may be up to 5 % for the AVATAR 10 MW rotor using a vortex wake rather than a BEM based code.

Wang, X.; Song, B.; Qian, Y., and Lao, J., 2020. Study of wind-induced vibration of a high-rise and thin-walled steel tower. In: Yang, D.F. and Wang, H. (eds.), Recent Advances in Marine Geology and Environmental Oceanography. Journal of Coastal Research, Special Issue No. 108, pp. 78–82. Coconut Creek (Florida), ISSN 0749-0208.There are many high-rise and thin-walled structures in the coastal environment. These structures easily produce vibrations under the action of wind load. Thus, it is necessary to study the wind-induced vibration response of the steel tower. The AR model method is used to simulate the natural pulsating wind velocity spectrum in different return periods. In addition, the wind-induced vibration responses of the integrated steel tower are successfully calculated using a numerical wind tunnel method. The reliability of the numerical method is verified by onsite monitoring. The results show that the responses of displacement amplitude gradually increase along with height. The larger the wind velocity, the larger the displacement response of the structure. The maximum displacement does not exceed the limit for displacement of the structure. The stress decreases along with the height, and there is a mutation of stress at the position of the variable cross-section. The greater the wind velocity, the higher the stress. Therefore, for wind resistance evaluation of this steel tower, the bottom and variable cross-sections should be controlled by stress and the top should be controlled by displacement.

The offshore structures that play a vital role in oil and gas extraction are always under complicated environmental conditions such as the random wind loads. The structural dynamic response under the harsh wind is still an important issue for the safety and reliable design of offshore structures. This study conducts an investigation to analyze the wind-induced structural response of a typical offshore deck structure. An accurate and efficient mixture simulation method is developed to simulate the fluctuating wind speed, which is then introduced as the boundary condition into numerical wind tunnel tests. Large eddy simulation (LES) is utilized to obtain the time series of wind pressures on the structural surfaces and to determine the worst working condition. Finally, the wind-induced structural responses are calculated by ANSYS Parametric Design Language (APDL). The numerically predicted wind pressures are found to be consistent with the existing experimental data, demonstrating the feasibility of the proposed methods. The wind-induced displacements have the certain periodicity and change steadily. The stresses at the top of the derrick and connections between deck and derrick are relatively larger. These methods as well as the numerical examples are expected to provide references for the wind-resistant design of the offshore structures.

Heliostats are sensitive to the wind load, thus as a key indicator, the study on the static and dynamic stability bearing capacity for heliostats is very important. In this work, a numerical wind tunnel was established to calculate the wind load coefficients in various survival stow positions. In order to explore the best survival stow position for the heliostat under the strong wind, eigenvalue buckling analysis method was introduced to predict the critical wind load theoretically. Considering the impact of the nonlinearity and initial geometrical imperfection, the nonlinear post-buckling behaviors of the heliostat were investigated by load-displacement curves in the full equilibrium process. Eventually, combining B-R criterion with equivalent displacement principle the dynamic critical wind speed and load amplitude coefficient were evaluated. The results show that the determination for the best survival stow position is too hasty just by the wind load coefficients. The geometric nonlinearity has a great effect on the stability bearing capacity of the heliostat, while the effects of the material nonlinearity and initial geometrical imperfection are relatively small. And the heliostat is insensitive to the initial geometrical imperfection. In addition, the heliostat has the highest safety factor for wind-resistant performance in the stow position of 90-90 which can be taken as the best survival stow position. In this case, the extreme survival wind speeds for the static and dynamic stability are 150 m/s and 36 m/s, respectively.

The practice of reproducing wind tunnel tests by means of CFD numerical simulations, which is known as numerical wind tunnel (NWT), is becoming quite common in many research fields of wind engineering. Wind tunnel tests can provide the indispensable validation data needed for CFD numerical simulations; at the same time, CFD can be considered a complementary support for wind tunnel tests in order to obtain a more comprehensive description of the flow field. In the present paper, NWT technique is applied to study the flow around and inside a multi-stage vertical-axis wind turbine (VAWT) surrounded by stator vanes. At first, the flow field has been studied in the wind tunnel by means of experimental tests. Then the experimental results have been used to validate a CFD model. The numerical model has finally been used to study and describe how the results obtained by means of the physical model can be extended to more general conditions.

To improve the flutter stability of a certain type fabricated steel truss bridge, a method of setting tuyere is put forward. Based on the two-dimensional 3 DOF coupling flutter method (2d-3DOF method), with the numerical wind tunnel established by computational fluid dynamics (CFD), the flutter stability control measures of tuyere is simulated. Through CFD numerical simulation, the flow field characteristics, flutter derivatives and critical flutter speed of origin and tuyere models are obtained. Through analysis, for the certain type fabricated steel truss bridge, the tuyere can improve its flutter stability. It illustrates the feasibility and reliability, and lays the foundation for further applied in practical projects.

Zhang, X.-T.; Chen, X.-J.; Wang, Q.; Li, P., and Zhou, H.-M., 2019. Numerical simulation of buffeting response of cable-stayed truss bridge with unconventional load in port. In: Gong, D.; Zhu, H., and Liu, R. (eds.), Selected Topics in Coastal Research: Engineering, Industry, Economy, and Sustainable Development. Journal of Coastal Research, Special Issue No. 94, pp. 275–279. Coconut Creek (Florida), ISSN 0749-0208.Wind and waves seriously threaten the safety of structures in coastal ports. In this paper, the long-span cable-stayed truss structure in port for ore transportation along the coast is taken as the analysis object, with the static three-point force coefficient which obtained based on numerical wind tunnel simulation, the buffeting response of structure induced by turbulent wind load is studied by time-domain analysis method. The results show that the amplitude of buffeting response induced by turbulent wind load is larger than that of static wind load and it is also found that the increase of the main girder retaining wall and the operation load have great influence on the buffeting response of the structure. The research results can provide a strong theoretical basis for the design of the project and similar projects.

As long span suspension bridges have high towers, large flexibility and low damping, it is a must to consider the wind-resistant stability in bridge designs, especially for sea-crossing bridges where there are always strong winds. To ensure the traffic safety under strong winds, wind screens are often installed on the bridge deck to reduce the wind speed over the roadway. In order to analyze the influence of wind screens on wind-resistant capability and driving security for long span suspension bridges, CFD wind tunnel technique is adopted to analyze the flutter stability, the buffeting displacement and the wind environment of the bridge deck with and without wind screens. According to the analysis, the installation of wind screens could effectively reduce the wind speed over the roadway, but it would also weaken the wind-resistant capability of the bridge. The analysis results could be used as reference for the wind-resistant capability optimization and the wind screen design for long span suspension bridges.

Storm cause deformation and collapse of structure, endanger people's life and property security. In order to avoid or reduce the impact of wind load effectively, the paper mainly introduce wind tunnel test, numerical wind tunnel method, time domain analysis, frequency domain analysis and the research and application of domestic scholars.

In this paper, the wind field around the flat box girder of a long-span bridge under 0o attack angle was investigated by the numerical wind tunnel technique, which can not only get the distributions of the pressure, velocity and vortex in the flow field, but also obtain the various aerodynamic parameters of the bridges. The velocity profiles were obtained, and the coefficient of tri-component from the numerical simulations was in good agreement with that from the wind tunnel test, which demonstrated that it was reliable and feasible to utilize the numerical wind tunnel technique to simulate the wind field and certificate the coefficient of tri- component of the bridge.

Using the FLUENT software, this paper taking the wind load shape coefficient in the current code for the design of building structures as the comparison standard, have numerical wind tunnel simulation of the wind the surface wind pressure on arch roof. It focused on the effect of the different turbulence models on the numerical simulation, such as Spalart-Allmaras, Standard k ε, RNGk ε, Realizablek ε, Standard k ω, SST k ωand RSM. It provided reasonable reference for selection of turbulence model.

ANSYS Fluent software is used in the simulation analysis of numerical wind tunnel model for the upper Spar platform module. Design Modeler (DM), Meshing, FLUENT and CFD-POST are chosen in the numerical calculation. And DM is used to deal with and repair the geometric model, and Meshing is used to mesh the model, Fluent is used to set up and solve the calculation condition, finally CFD-POST is used for post-processing of the results. The wind loads are obtained under different direction and incidence angles. Finally, comparison is made between numerical results and empirical formula.

The accurate evaluation of wind loads applied on floating offshore structures is extremely important as they are in specific conditions one of the dimensioning criteria for the mooring design. Nowadays these loads are mainly assessed through wind tunnel tests performed at model scale. Estimating realistic wind loads however, remains a big challenge. The complexity and associated simplification level of FPSO topside structures, the scale effects and the establishment of the atmospheric boundary layer imply that many simplifications are to be made. Typically, the FPSO topside is greatly simplified and equivalent blocs of wired frame are used. Today with the evolution of CFD software, and the increase of the meshing capacity, new scopes open to CFD. Aerodynamic simulations on complex FPSO structures are therefore now possible, but need specific developments and validations that are presented in this paper. The main objective of the work presented is to investigate the ability of CFD to evaluate wind loads on complex FPSOs topsides and to provide information on the impact of model simplifications made in wind tunnels. In a first stage, the numerical model was intensively validated by comparing its results to a wind tunnel test case. The numerical model was developed in order to ensure the quality of the results and enable a relevant comparison that was obtained with grids density up to 30 million cells. For this purpose, the geometric model used corresponds to the one used in wind tunnel. The same Atmospheric Boundary Layer was simulated and a thorough effort was performed to ensure the mesh convergence. In a second stage, more physical aspects of the wind tunnel methodology were investigated. Typically the accuracy of the blockage effect correction was evaluated by performing computations with and without blockage, and results were compared with classical corrections applied in wind tunnel. The impacts of the Atmospheric Boundary Layer on wind loads have also been investigated. Finally, the wind load contribution of each component of the FPSO was evaluated.

The most of Long-span stadium roofs are complex surface, the load norms cannot put forward the design requirements clearly in frequently. Determine wind loads need to use other means for help, while the numerical wind tunnel is one of the commonly be used to research methods in recent years. This paper introduces about the numerical simulation method of a long-span stadium roof surface wind pressure distribution , and based on FLUENT platform, a gymnasium as an example, the shear stress transport k - ω model (referred to as the SST k - ω model) on the roof surface wind pressure distribution of numerical wind tunnel simulation, analysis stadium roof surface pressure distribution law based on different wind directions.

Using the FLUENT software, this paper taking the current code for the design of building structures as the comparison standard, have numerical wind tunnel simulation of the wind the surface wind pressure on low layer double slope roof. It focuses on the analysis of the effects of turbulence model selection on the numerical simulation results, such as Spalart-Allmaras、Standard k −ε、RNG k −ε、Realizable k −ε、Standard k −ω、SST k −ω and RSM, to provide a basis for the reasonable selection of turbulence models.

using the FLUENT software, this paper taking the current code for the design of building structures as the comparison standard, have numerical wind tunnel simulation of the wind the surface wind pressure on arch roof. It focuses on the analysis of the effects of three kinds of pressure velocity coupling algorithm on the numerical simulation results, respectively SIMPLE, SIMPLEC, PISO, to provide a basis for the reasonable selection of algorithm.

For numerical wind tunnel method has the advantages of low cost, fast speed, the more comprehensive results, the paper using CFD knowledge and the FLUENT software, using RSM turbulence model, SIMPLE algorithm, simulation class D landform, to have numerical simulation of average wind pressure coefficient for of the circular planar and saddle roof building ,which the current code for the design of building structures did not give, to provide reference for determining the average wind pressure coefficient of the circular planar and saddle roof building .

The existing “structure load code” did not give wind load shape coeeficient of rhombic plane and saddle-shaped roof .On this issue, numerical wind tunnel method has significant advantages such as low cost,fasting,collecting more comprehensive results.Using information of CFD and the software of FLUENT, using RNG - turbulence model, simulating a landform rhombic plane, the paper had numerical simulation of average wind pressure coefficient for rhombic plane and saddle-shaped roof building. It focused the effect on the numerical simulation for bending-span ratio. Finally it provided reference for reasonably determining the average wind pressure coefficient of rhombic plane and saddle-shaped roof building.

Air cooled thermal power structure is composed of spatial steel truss and steel-concrete tubular columns. Permeable “A” shape structure and wind-break wall are installed on its top. The wind load in the wind-break wall has great effect on its lower part. The structural wind parameters is not clearly stipulated in current load code. To solve the problems of wind parameter value in design and effectively evaluate the influence on wind-break wall form to the structural wind-resistant properties, three different wind-break wall forms are presented. Wind properties on an actual air cooled thermal power structure under three different wind–break wall forms are simulated with FLUENT software. Wind pressure law on “A” type structure and wind-break wall under different wind-break wall forms and at different wind direction angles is studied. Every division section shape coefficient of wind-break wall and “A” type structure under different conditions is obtained. The wind presure distribution law and the most reasonable wind-break wall form is obtained.

A brief introduction of Nanchang International Financial mansion manometry test model was stated first, And based on the Fluent software platforms, Wind pressure on the surface of high-rise building with the influence of adjacent buildings is simulated by computation fluid dynamics (CFD) methods. The results show that the numerical wind tunnel to some extent, more in line with the measurement results, but the errors in some parts are still large, relevant results will provide references for the research and the engineering practice.

Due to the increasing of wind disaster, structural wind engineering arouses more and more attention recently, with rapid development on spatial structure and continuous innovation of structural style. The main purpose of structural wind engineering is to calculate the wind pressure coefficients of structure. In this paper, the numerical wind tunnel method (NWTM), based on the Computational Fluid Dynamics (CFD), is applied to study wind load. The wind pressure coefficients of reticulated spherical shell with the 4.6m high wall were first determined, using the NWTM. The results are then compared with the wind tunnel test (WTT) and good agreement is found. The feasibility and reliability of NWTM were then verified. As the second example, NWTM is carried out to predict wind-induced pressure on reticulated spherical shell without wall. Further the distribution behavior of wind pressures on this kind of structures is discussed which could provide professionals the reference for the design of structure.

Problem of lateral driving stability of the automobiles passing by the vicinity of pylons of cable-supported bridges in condition of strong cross wind exists obviously because of the alternative wind environment above the deck due to complex flow fluid around the pylon and the deck. Based on numerical wind tunnel technology, the numerical simulation investigation of alternating wind environment above the girder near A-shaped pylon for main span of the steel truss girder cable-stayed bridge of Zhengxin Yellow River Highway-railway Bridge is carried out, considering wind barrier set up on the deck or not. The result shows that the original program has significant effect on wind speed amplification and mutation near the pylon domain in cross wind. Further investigation on wind barrier set up on both sides of the girder section or near the A-shaped pylon along the bridge gives that wind barrier near the A-shaped pylon is useful for reducing wind speed above the leeward deck near the pylon and weakening its mutation. Deeply, taken a medium-size commercial bus as an example, lateral driving stability of the automobiles passing by the leeward lane near A-shaped pylon is discussed through the dynamic response simulation of the vehicle controlled by ideal-driver under cross wind. The results confirms again that the wind barrier near the A-shaped pylon is good for driving safety of vehicles passing by the leeward lanes in vicinity of A-shaped pylon. In all, above work provides technical support for the final implementation of the wind barrier as an engineering measure.

This paper presents the results of full-scale numerical wind tunnel tests of wind pressure on structure roofs with suspension solar panels. Solar roof project is popularized in this century. Solar panels are suspended above the structure roof. So the wind load effect on the structure roof is varied. The wind tunnel experiments are often expensive. A 3D model is introduced and solved using ADINA. The wind pressure distribution coefficients are calculated.

Numerical procedure (Kratos) to replace wind tunnel tests.CFD and CFD with ALE (Arbitrary Eulerian-Lagrangian) analyses.Tests on Great Belt and bridge on Adige river cross section. The aim of the present study is to propose a reliable engineering procedure to analyze bridges subjected to wind loads by-passing the expensive wind tunnel tests thanks to numerical simulations. These exploit Kratos, a free multi-physic FEM code developed by the Kratos Team at CIMNE in Barcelona, and, specifically, an adaptation to the long-span bridge case of its numerical tool for simulation of in-wind ultra-lightweight structures developed within the uLites project (supported by the Research Executive Agency in the Seventh Framework Programme of the European Union, SP4-Capacities, Research for the benefit of SMEs, FP7-SME-2012 GA-314891, see http://www.cimne.com/websasp/ulites/). Time histories of the forces induced by the flow around the sections are used to calculate aerodynamic and aeroelastic parameters through statistical, frequencies extraction and fitting algorithms. Several analyses have been performed to derive rules for a reliable and stable evaluation of these aggregated parameters for engineering purposes. Results obtained for the sections of Great Belt Bridge (Denmark) and of the bridge on A31 highway over Adige river (Italy) are shown. Both static analyses (CFD procedure with fix boundaries) and imposed-displacements analyses (CFD with ALE) give results that are comparable with those coming from wind tunnel testing and from literature; evaluated parameters also manifest regular trends and values little influenced by CFD setting. These facts represent proofs of the reliability of the proposed procedure.

Wind is a key factor when determining the safety of high-rise structures, such as buildings, chimneys, or towers. Using dampers to control wind-induced vibration is a safe, effective, and economical method for high-rise structures to employ. In this paper, viscoelastic dampers (VEDs) were used to reduce the dynamic responses of a 75-metre-high chimney. First, a simulation method for the stochastic wind field, based on the modified Fourier spectrum, was proposed. The method provided the accurate data of the wind velocity time history, which then simulated wind pressure through the use of a numerical wind tunnel. Then, the finite element model for the Madagascar chimney structure was built, and a wind-induced vibration analysis of the structure with and without VEDs was carried out under the simulated wind excitation. The optimisation – method, based on the genetic algorithm, was used to optimise the location of the VEDs. It was concluded that the accuracy of the modified Fourier spectrum method (MFSM) was greatly improved, when compared to the spectrum representation method of simulating the stochastic wind field. VEDs can effectively reduce the dynamic responses of chimney towers, especially for the displacement responses. In addition, the proposed optimisation method quickly determined the optimum positions and necessary quantities of VEDs to use, which yielded effective vibration mitigation.

Plate-cone reticulated shell is a new type of space steel structures with good mechanical behavior and technical economy. In this paper, by using the wave superposition method, the fluctuation wind loads are simulated. According to the structural behavior of plate-cone reticulated shell, the structural shape factors of wind load for plate-cone reticulated shell were gained with numerical wind tunnel simulation based on Computational Fluid Dynamic(CFD) method through simulating wind field variation around plate-cone reticulated shell, and comprised with the common reticulated shell's shape factors of wind load suggested by the Code for loads, some important conclusions for plate-cone reticulated shell are obtained for practical design.

Wind environment above the deck near the pylon of cable-supported bridge or arch foot of arch bridge is very complex in condition of strong cross wind, thus affecting the bridge towers of cable-supported bridge or arch bridge deck and other parts of the high winds driving environment is very complex, thus affecting the controllable stability of passing vehicles. Based on numerical wind tunnel technology, the numerical simulation investigation of alternating wind environment above the girder near A-shaped pylon for main span of the steel truss girder cable-stayed bridge of Zhengxin Yellow River Bridge is carried out, the result shows that the original program has significant effect on wind speed amplification and mutation near the pylon area in cross wind. Further researches aiming at wind barrier set up on both sides of the girder section or near the A-shaped pylon along the bridge are also presented; one type of wind barrier project is obtained, which is useful for reducing wind speed above the leeward deck near the pylon and weakening its mutation, and also provides technical support for the final implementation of the wind barrier as an engineering measure.

A high efficiency simplified finite element analysis method is presented to analyze the iced galloping, which is characterized by large amplitude vibrations of iced, multi-span, electrical transmission conductors. Based on ANSYS/LS-DYNA, the springs-transmission conductors model was established that springs were used to copy the actions of tower to transmission conductors, the Mixed form-finding method is presented and which take the initial form of fixing wires and icing load into count, numerical wind tunnel technology based on CFD numerical simulation is used to study the aerodynamic characteristics of the ice-coated conductor. A simplified galloping analysis method of multi-span transmission conductors was proposed and verified. Based on the 1000kV Han River long-span power transmission tower line project, simplified calculation of transmission conductors galloping was performed.

For the limitations of the research methods, emphasis has always been put on the dynamics of the bridge sections with no concern about the flow structure around the decks, when carrying the research of the mechanism of wind-induced vibrations. The emergence of PIV (particle image velocimetry) makes it possible to analyze the flow structures. In order to inspect the relationship between the dynamics of decks and the flow structures around the decks, the static force coefficients of the bridge slotted decks and the velocity maps are marked and analyzed using numerical wind tunnel tests. Snapshot POD method is carried out to analyze the flow structures around the decks to find the dominant vortices in the flow filed. The fluctuating velocity maps are reconstructed using the first several modes with most of the energy contained. The research shows that in the flow field around the decks there are some periodic moving vortices. Relationship is found between the rule of the kinemics of the vortices and the static force coefficients of the decks. The research in this paper will guarantee the theoretical basis for investigating the micro mechanism of wind induced vibrations of bridges using the method of PIV.

The detail design and development of a high downforce aerodynamics package for a Formula SAE car is described. Numerical methods are first used to develop multi-element wing profiles which conform to FSAE rules while still generating high negative lift coefficients. A range of full scale wind tunnel testing data is presented for these designs, demonstrating their performance, both in isolation (free-stream), and on the car. Three different techniques are also developed for measuring the performance of a front wing in ground effect.