Wind tunnel tests and the improved delayed detached eddy simulation (IDDES) were carried out to study the aerodynamic characteristics of a train with a wind barrier in different lengths. The results were obtained at 20° and 30° yaw angles, which are the highest realistic values for high-speed trains. The rationality of the experiment was assessed according to standards, based on which the accuracy

In this study, atmospheric motion vectors (AMVs) were derived from the satellite images predicted using a generative adversarial network (GAN) and a deep multi-scale frame prediction algorithm. The GAN was trained and tested with a sequence of the satellite images of a COMS satellite infrared-window channel under the 68 tropical cyclones. The inputs of the consecutive satellite images with 15-min interval

Windborne debris is a major cause of damage to the built environment during tornadoes. A fundamental step for quantifying this damage is to provide models that are able to describe the trajectory of the flying debris and thereby determine their impact location and associated momentum/energy. This goal can be achieved through the adoption of an appropriate three-dimensional (3D) six-degrees-of-freedom

The performance and durability of wall assemblies are greatly affected by the moisture load to which they may be subjected, in particular those arising from Wind-Driven Rain (WDR). Standard approaches for estimating such moisture loads assume 1% of the WDR load, whereas these loads have also been assessed from watertightness tests, although these assumed loads have been determined based on limited

In the present study, the vortex-induced force was investigated for an oscillating rectangular cylinder with the side ratio of 5 (B/D ​= ​5, B: breadth of the cylinder, D: depth of the cylinder) encountering a sinusoidal streamwise gust by wind tunnel tests and computational fluids dynamics (CFD) simulations. For the experiments part, a multiple-fan active-controlled wind tunnel was used to generate

The present study examines the possibilities of transferring drag measurement results on reduced-scale train models to the respective full-scale vehicle. A comprehensive experimental and numerical study of the boundary layer and skin friction along trains is performed, focusing on Reynolds number effects. The data are supplemented by an extensive literature study and compared with different approaches

The aerodynamic damping reflects the aero-structure interaction and is intrinsically involved in a fully coupled turbine. However, it is still of great importance to theoretically quantify the aerodynamic damping of a HAWT in some cases. The existing theory can reasonably characterize the aerodynamic damping level of a HAWT with rigid blades, minute shaft tilt and yaw angles, while certain discrepancies

The wind effects on a ground-mounted solar panel under the influence of the panel tilt angles and wind directions were investigated; both experimentally and numerically. The ground-mounted solar panel was used with tilt angles of 25° and 45° for a Reynolds number of 6.4 ​× ​104. Wind directions were varied from 0° to 180° at 30° intervals. A constant-temperature hot wire anemometer and a pressure scanner

The effect of canyon cross wind yaw angle on airflow and flame characteristics of ethanol pool fires in a tunnel was investigated. The fire source location and canyon cross wind speed were studied as factors. The wind yaw angle was ranged in 45°–135° with an interval of 15°. The results showed that the flow field in the tunnel presented three different conditions with the boundaries of wind yaw angles

The influence of the end effects in the wake development of a vertical axis wind turbine is studied using a Large-Eddy Simulation methodology, coupled with an Immersed-Boundary technique, for a value of solidity σ ​= ​Nc/D ​= ​0.5 (N: number of blades; c: chord length of the blades; D: diameter of the turbine), a tip speed ratio TSR ​= ​RΩ/U∞ ​= ​2.206 (R: radius of the turbine; Ω: angular speed; U∞:

Tornadoes cause damage to buildings and infrastructure. Providing the spatially varying tornado activities or tornado occurrence rate alone does not facilitate the tasks of checking and evaluating structures subjected to the tornado wind velocity hazard. In the present study, the estimation of the quantile of the tornado wind velocity hazard along the height for southern Ontario – a tornado-prone region

In recent years a renewed interest in platooning has emerged due to increasing pressure on vehicle manufacturers to reduce greenhouse gas emissions of their fleets. Vehicles traveling in close proximity have been studied in some depth, particularly simplified bodies and North American trucks. Still, there is a lack of understanding of the benefits of platooning for European style trucks. In this study

This paper presents the wind-induced responses and wind resistant design method of arch-supported membrane structure. Series of rigid model wind tunnel tests are carried out to record wind pressure data on the roof surface of experimental models. Random vibration time history analysis is employed to get wind-induced responses. Geometric nonlinearity is taken into account in dynamic analysis. Effects

Modelling and forecasting the temporal behaviour of wind is of substantial importance in a variety of applications, which depend largely on the understanding and quantification of its variability. Existing literature focusing on wind speed variability is predominantly associated with horizontal wind component, whereas the knowledge of vertical wind component is much less documented. This paper investigates

Large-eddy simulations are performed to study the wake of a wall-mounted finite-length rectangular prism at a Reynolds number Re ​= ​1.2 ​× ​104 for the prism aspect ratio AR (= h/a) ​= ​7 and the boundary-layer thickness ratio δ/h ​= ​0.08, where h is the prism span and a is the frontal width of the prism cross-section. Besides, parallel experiments are conducted to provide validation for the numerical

Employing large Horizontal Axis Wind Turbines, HAWTs, is inevitable for increasing the wind power generation per turbine unit, i.e. reducing the cost of wind energy production. The consequences of large HWATs application are considerable aeroelastic blade deformation and high levels of aeroacoustic noise generation. In this paper, considering the aeroelastic effects, aeroacoustic calculation of a MW

The purpose of this study is to develop a semi-analytic model for the prediction of broadband inflow noise of an airfoil in the frequency-domain, which can account for the effects of real airfoil geometry on the radiated sound pressure field in both phases of propagation and generation of aerodynamic sound. First, an acoustic transfer function is analytically derived to account for airfoil geometry’s

Three-dimensional (3-D) aeroelastic effect is known as the main factor that leads to the discrepancy between the critical flutter states predicted by two-dimensional (2-D) deck section and 3-D full structure. The 3-D aeroelastic effect on flutter performance of long-span bridges was investigated through historical experimental data statistics, numerical flutter analysis and wind tunnel tests. The critical

A novel technique for producing a steady lift force on a circular cylinder in a uniform flow driven by the longitudinal vortex (LV) is developed. The LV forms behind the cylinder when a strip plate is located downstream in a cruciform arrangement. The upstream cylinder can stably move by itself via an aerodynamic effect of the LV-produced steady lift force. However, the effects of geometrical parameters

This paper examines the aerodynamic mechanisms associated with gust effect factors for windward walls of rigid buildings. The analysis utilizes two experimental databases with 58 rectangular-plan building models. Statistical characteristics of windward wall pressures, such as skewness, kurtosis, and peak factors, are examined along with parameters related to the wind spectra and the aerodynamic admittance

Characteristics of turbulent flow over a steep escarpment were studied using a 1:25 scale model of the Bolund hill in a wind tunnel under neutral atmospheric stability conditions. The influence of Reynolds number, inflow shear profile, and escarpment geometry were investigated in relation to flow behavior including separation and reattachment, Reynolds stresses, vorticity, Turbulent Kinetic Energy

Previous studies have shown that the accuracy of the ISO semi-empirical wind-driven rain (WDR) model can be improved by applying more detailed wall factors determined based on high-resolution field measurements. However, discrepancies between measurements and predictions still exist. The availability of high-resolution WDR field data collected over a long period of time makes a detailed analysis possible

Blockage effects on the aerodynamics of rectangular prisms, which represented isolated tall buildings, under uniform turbulent flows were investigated experimentally. Wind tunnel tests were performed on models for four blockage ratios (BR ​= ​4.1%, 6.1%, 8.4%, and 10.1%) under the uniform flows for three turbulence intensities ((IU=0.1%, 4%, and 8%) using the synchronous pressure measurement technique

This study quantifies the influence of the local topography on sonic anemometer measurements mounted on tall met-masts deployed in Norwegian fjords. This assessment is done by analysing the second-order structure of turbulence in the frequency space. The objective is to evaluate how the data collected by these masts can help with the design of future fjord-crossing bridges. Using measurements from

Evaluation of equivalent static wind load has been one of the most important topics among wind engineering researches. Over the years, methodologies have been developed to evaluate the equivalent static wind load for a single-target structural response (S-ESWL here). However, it is still challenging to apply these methods to large and intricate structures. Evaluation methods based on multiple targets

This experimental work aims to investigate the manipulation of a bluff body flow with a yaw angle of 10° based on a genetic algorithm optimization. Two loudspeakers are used to generate zero-net mass-flux jets through streamwise slots, which span a large portion of the rounded A-pillars of the bluff body. The actuations produce a maximum drag reduction of 17% and 2% for the leeward and windward side

An effective flow separation control method is urgently needed to improve the aerodynamic performance of the wind turbine blades. The leading-edge protuberances (LEPs) are the method that can inhibit flow separation and improve the aerodynamic performance of wind turbine airfoil. In order to achieve the optimal design of the LEPs on the wind turbine airfoil, it is necessary to develop a theoretical

Windborne debris (WBD) is one of the significant causes of damage to civil structures and infrastructures and economic loss under extreme winds, such as hurricanes and tornadoes. The impact of WBD with high momentum damages the building envelope and may further threaten the integrity of the entire structure. This study presents a comprehensive review of current literature on interactions between wind

Typhoon winds near its external eye wall are not only strong but also nonstationary with time-varying coherences. This study proposes a conditional simulation method for multivariate nonstationary typhoon winds with time-varying coherences for long-span bridges. The Kriging method for conditional simulation and the time-varying wind spectrum and coherence are first introduced. The decomposition of

Fluctuating winds from intense thunderstorm/downburst are often modelled as the amplitude modulated evolutionary stochastic processes and simulated based on the spectral representation method. Aspects of the modelling and simulation include assessing time and frequency dependent power spectrum, and the identification of the amplitude and frequency modulations are not straightforward. The present study

Wind-induced vibration (WIV) of tall buildings is a major cause of occupant discomfort and potential fatigue damage. Catastrophic failure may also take place at wind speeds that are lower than the design values due to phenomena such as vortex shedding or flutter-induced instabilities. This paper presents a data-driven adaptive control strategy that continuously seeks to minimize WIV for a given average

The observation data in the development stage of dust storms induced by cold front were analyzed. The results showed that the contribution of outward and inward interaction to dust and heat transport were less than that of ejection and sweep events. That is, the transportation of dust and heat was not dominated by interactions. In the ejection events, the low- and high-frequency fluctuations dominate

Long-span bridges are strongly sensitive to wind, and it is important to accurately assess the wind field of bridge sites. Thus, to strengthen the understanding of the wind field of deep-cut gorges and study the influence effect of the wind direction on the wind characteristic parameters, the wind data from an ultrasonic anemometer installed on a catwalk and bridge tower were used to perform statistical

Unbalanced snow distribution is one of the main reasons for the collapse of multi-span arch roofs due to excessive snow loads in the valley and leeward areas. The formation of uneven snowdrifts is closely related to the shape of the building as it seriously affects the turbulent structure and snow drifting process. This study aims to investigate the snowdrift characteristics of multi-span arch roofs

When a tunnel fire occurs, the response speed of the ceiling-mounted smoke or thermal detector is of great significance for controlling the fire. The information on the ceiling jet flow is important for detector installation and design. In this paper, a series of numerical simulations and experiments are conducted to investigate the jet flow velocity in tunnel fire during different stages. The ceiling

A Lattice-Boltzmann-based Large-Eddy Simulation approach for wind load prediction on high-rise building is proposed and validated. An extension of the original incompressible Synthetic Eddy Method to reconstruct inlet turbulence is proposed within the Lattice-Boltzmann framework, including a low-noise frozen density variant. Extensive successful comparisons with experimental data are carried out, for

Tapering is a common morphological modification to ensure the stability of civil structures, especially as more and more high-rise buildings push the skyline of modern cities. However, the aerodynamics, aeroelasticity, and fluid-structure-interaction of tapering remain far from been fully understood. Through wind tunnel tests, the present work offers some notable observations on the effects of tapering

The generation of inflow turbulence is the first necessary step to conduct a successful large-eddy simulation (LES) of atmospheric boundary layer (ABL) flows. It is required that the generated inflow turbulence is divergence-free and satisfies essential target statistical properties, including the two-point statistics of the flow described by the coherency function and the spatial correlation. In this

The market for single medium and large-scale wind turbines deployed at industrial consumer sites has future expansion potential, due to evolving electricity systems from centralised to distributed. Many industrial sites have low-rise buildings, typically found in peri-urban environments, such as at the edge of towns and cities. Unlike rural onshore wind farm sites, peri-urban wind environments can

Efficient transportation is an important factor for regional socio-economic growth. Excitations from wind loads and road motions can influence vehicle-driver behaviour in a way that may impair transportation. This is especially true in open areas such as long-span bridges. This paper investigates the influence of wind loads and floating bridge motions on bus lateral stability for the straight concept

The paper investigates the local topographic effect on the mean and integral flow characteristics recorded by sonic anemometers mounted on tall masts near the shoreline of three different Norwegian fjords. Two years of measurements are analysed, using data from 25 three-dimensional sonic anemometers mounted at heights from 12 ​m to 95 ​m above the ground. The goal is to explore the potential and challenges

The aerodynamic characteristics of a hyperloop vehicle with or without channels operating at subsonic speeds in a low-pressure tube were simulated using a scale-adaptive simulation (SAS) method based on the shear-stress transport (SST) κ-ω turbulence model. The aerodynamic behavior of the hyperloop pod, fluid flow, and heat transfer phenomena in the tube were analyzed and evaluated. The grid resolution

This paper is aimed at selecting a suitable pantograph-catenary model for investigations under crosswind and investigating parameter influences on pantograph-catenary dynamics, including the friction, the rising angle, the value of zigzag and the sliding plate irregularity. One spatial-beam pantograph model is proposed and its governing equations are obtained. Combining with the catenary, the 3-D pantograph-catenary

In the present study, novel release mechanisms were developed for laboratory simulations of density-driven downbursts using the two-fluid model. The ability of these new designs in producing repeatable outflows was examined and the influence of minimizing the release cylinder wall effect was tested. The entire experimental setup was also modified to simulate the effect of translation on the resultant

Based on 3- D, unsteady compressible Navier-Stokes equations and SST k-ω two-equation IDDES turbulence model, the effect of cross passage on aerodynamic characteristics of evacuated tube transportation is simulated by overset mesh technology. The flow structure, aerodynamic force and aerothermal environment in three train/tube configurations are studied. The results show that there is a linear relationship

Railway vehicle roll-over under strong cross-wind action is significant problem considered in the context of vehicle aerodynamics. Train accidents induced by wind occurring in last two decades resulted in safety procedures concerning this phenomenon included in specifications or standards. Assessment of railway vehicle aerodynamic stability is conducted on the basis of roll-over critical velocity,

There are a number of long-span bridges located in the southeast coastal bay of China which is prone to typhoons. Very limited studies have been made of the wind field characteristics in this bay which is special as it has various changes in fetch from sea to land and vice versa, depending on the wind direction. Thus, a detailed analysis of the wind properties of the 2019 Typhoon Bailu has been carried

Extreme winds such as thunderstorm winds typically exhibit nonstationary characteristics. When these winds act on the structure, the time domain analysis method is used considering the structural and/or aerodynamic nonlinearity in the wind-induced structural response analysis. Because the time domain analysis method needs a sufficient number of wind speed samples, the efficient simulation of nonstationary

Measurements of tropical cyclones (TCs) at landfall in their inner regions are limited. Typhoon York (9915) stroke Hong Kong directly at a typhoon-strength level in 1999, and resulted in the most severe TC-related disasters in the region since 1983. During the passage of York, the Hurricane Signal No.10, which is the highest level of TC warning signal in Hong Kong, had been hoisted for a record-breaking

A rectangular cylinder in a fluid flow is known to show complicated cross-flow vibration behavior due to the interaction between the Kármán vortex-induced vibration and galloping. Wind tunnel experiments were carried out to investigate the cross-flow vibration behavior of several rectangular cylinders for which different stream-wise lengths, B and a fixed cross-flow height, D were used to define the

The downburst wind is an extreme wind event with rapidly increasing and afterwards descending wind velocities in a short period. The prediction of downburst winds, especially for the peak wind velocity and its occurrence time, is a critical issue in engineering communities. In this paper, typical commonly used time-series models are firstly employed to predict the downburst winds based on measured

Accurate determination of wind load is of great importance for the wind-resistant design of building structures. Despite the fact that air density varies systematically with altitude, and somewhat less so with barometric pressure, air temperature, and latitude, there is a lack of studies on the dependence of wind load on air density especially for highrise buildings. This article presents a special

Large-scale atmospheric turbulence produces large-amplitude low-frequency fluctuations of the angle of attack, width can significantly change the self-excited forces acting on a bridge deck. Such a nonlinear effect must be carefully modelled for an accurate prediction of the dynamic response of long-span suspension bridges to the turbulent wind. By assuming that the angle of attack varies slowly a

The improved delayed detached eddy simulation (IDDES) was used to study the influence of the platoon configuration of trains on its aerodynamic performance. CFD simulations were validated against the wind tunnel test and different mesh refinement to further verify the flow field around the high-speed train. The platoon configuration mainly affects the aerodynamic forces of the tail car of the front

The dynamic responses of railway vehicles under crosswinds are investigated by using multibody dynamic simulations and compared with the experimental data. A new gust model is also proposed to predict aerodynamic forces acting on railway vehicles under tunnel exit winds. The dynamic responses of a model vehicle under tunnel exit winds are firstly predicted by multibody dynamic simulations and the predicted

Atmospheric stability, which has received widespread attention in recent years, has a significant impact on the performance of wind farms. However, majority of traditional wind farm layout optimization (WFLO) studies assume that atmospheric stability is always neutral. Hence, to consider the influence of atmospheric stability, we developed a novel WFLO framework based on an improved Gaussian wake model