Wind-induced Effects Research Articles

Approaches to substantiating the placement of industrial facilities within the sanitary protection zones of surface watercourses

Introduction. The article considers an approach to be used to delineate the source water protection area for the surface water bodies without putting manufacturing plants within the delineated areas out of action. The approach is based on the assessment of the disposals produced by plants on the water quality at the surface water intake point during the plant’s accident-free operation and both accidents within and beyond the design basis. Materials and methods. The article used the water protection area laws and regulations, the data observed of the disposal dispersion in the large rivers, and the original articles presented in databases and information systems: RSCI, CyberLeninka, Scopus, Web of Science. The solute transport analytical solutions for the dilution of the linear source in the flow serve as the methodological framework. Results. The article results have shown the local disposal into the river to form dispersion halo. Due to the specific dispersion processes, an area of a strip-like shape on the opposite shore can be formed where an anthropogenic influence is not present or negligible. This can be considered the background for the safe cooperative operation of the water intake and a manufacturing plant located within the water protection area. Limitations. The present article outlines the analytical approach for estimating the dilution of wastewater in river waters. The methodologies proposed are subject to several constraints, including the assumption of a constant river channel width and profile, steady discharge of contaminated wastewater, absence of water inflow losses or replenishment, lack of interaction with suspended particulate matter, uniform mixing across all segments of the river, and neglect of wind-induced effects on pollutant dispersion near the water surface. Failure to meet any of these assumptions necessitates recourse to more sophisticated numerical modelling techniques for accurate calculation. Conclusion. The use of the approach presented in the paper allows justifying the manufacturing plant’s operation within the source water protection area for the surface water bodies.

Impact of Active Galactic Nuclei Feedback on the Dynamics of Gas: A Review across Diverse Environments

This review examines the relationship between black hole activity and kinematic gas–star misalignment in brightest group galaxies (BGGs) with different merger rates. The formation history of galaxy groups is assessed through “age-dating” as an indicator of distinct major mergers involving the BGGs. BGGs within groups characterized by a higher frequency of major mergers are more likely to host active SMBHs. A consistent correlation is identified between the level of black hole activity, as indicated by the 1.4 GHz and 325 MHz radio emissions, and the degree of kinematic misalignment between the gas and stellar components in BGGs. In dynamically fossil groups, where black hole accretion rate is relatively (∼1 dex) lower due to the lack of recent (≤1 Gyr) major mergers, there is reduced (∼30%) misalignment between the gas and stellar components of BGGs compared to non-fossil groups. Additionally, this study reveals that BGGs in non-fossil groups show higher levels of star formation rate and increased occurrence of mergers, contributing to observed color differences. Exploring the properties and dynamics of the gas disk influenced by mechanical AGN feedback through hydrodynamic simulations suggests that AGN wind-induced effects further lead to the persistent gas misalignment in the disk around the supermassive black hole.

Case Study of Analysis of Wind Load on U and V Shape High Rise Building: A Review

Conclusively, this case study provides an exhaustive and methodical investigation of wind load analysis on U and V-shaped high-rise structures, amalgamating conclusions from diverse scholars in the domain. The comprehensive examination and juxtaposition of current research techniques highlight the complex character of wind load assessment, utilizing a range of methods including wind tunnel testing, empirical observations, and Computational Fluid Dynamics (CFD) simulations. The research makes a substantial contribution to our comprehension of the complex relationships that exist between wind forces and the unique architectural arrangements of U and V shapes. By assimilating insights from numerous studies, the research successfully unveils commonalities, identifies divergences, and highlights emerging trends in the analysis of wind-induced effects on these high-rise structures. Professionals in high-rise building design, and architects and engineers. The goal of the research is to make a substantial contribution to the ongoing development of wind load analysis techniques.Understanding the building's response to wind rotation at different incident angles is a specific focus of this study. Validation against experimental data ensures the accuracy of CFD simulations, often involving model refinement based on real-world observations. Overall, this research contributes to a comprehensive understanding of building aerodynamics, offering insights into the intricate interplay between structures and wind forces. Keywords: High-rise building, ANSYS CFX, CFD, wind tunnel, pressure coefficient.

Analysis and design of PI-based controllers for the axes of European Solar Telescope

European Solar Telescope (EST) represents the largest European research infrastructure projected in the field of solar astrophysics. It is a 4-meter class solar telescope currently in the design phase. Within this phase, an essential objective is to analyze the control strategy of the telescope axes to achieve an accurate sun trajectory tracking. This paper presents a cascade control scheme based on proportional-integral (PI) controllers specifically designed for the elevation and azimuth axes of EST. The control strategy, which employs nested position-velocity loops, is devised to adeptly track the sun’s trajectory while mitigating wind impact. The controller tuning adheres to criteria of relative stability margins and bandwidth constraints using the state-space representation derived from Finite Element Model of the EST structure. An end-to-end dynamics model has been proposed to evaluate the performance of the control strategy during a ten-minute simulation. Results evidenced the convenience of the proposed controllers, highlighting wind as the main source of the control error (0.78 arcsec and 0.14 arcsec in azimuth and elevation axes, respectively) compared to the sun tracking error. Future control strategy enhancements should target the reduction of wind-induced effects to meet stringent image stability requirements.

Inversion of wind load on high-rise buildings under non-stationary and non-Gaussian conditions via DKF and FB-FFT

Wind-induced effects should be especially concerned for the design and maintenance of high-rise buildings, and information of wind load is sometimes prerequisite for related wind-resistant practices. Previous studies have been mainly conducted to deduce wind load on high-rise buildings under stationary and Gaussian conditions. However, due to the inherent randomness, wind load often exhibits non-stationary and non-Gaussian characteristics. This study employs two methods, namely Discrete Kalman Filter (DKF) and Fast Bayesian Fourier Transform (FB-FFT), to estimate wind load on high-rise buildings under non-stationary and/or non-Gaussian conditions. Firstly, a numerical building model is employed to evaluate the inversion performance of the two methods. Subsequently, both methods are applied to determine the wind load on a real building. Results through numerical simulation analysis demonstrate that DKF can invert the base force and modal force accurately under non-stationary conditions. For stationary non-Gaussian cases, the inverted wind load approximates the target force in terms of amplitude, but the inversion result exhibits Gaussian characteristics. FB-FFT can be basically utilized to invert the modal force under varied concerned conditions, yet the estimated wind load for stationary non-Gaussian case is slightly smaller than the target value. In reference to the real high-rise building example, DKF is found to produce similar results to those determined on the basis of wind tunnel test and in-situ measurement. Meanwhile, results of model force obtained via the two methods agree with each other. The above findings suggest that DKF and FB-FFT can be employed, at least partially, to deal with the issues of wind load inversion under non-stationary and non-Gaussian conditions.

Evaluation of sea surface roughness parameterization in meso-to-micro scale simulation of the offshore wind field

Accurate parameterization of the wind-induced effects on the Marine Atmospheric Boundary Layer (MABL) is of fundamental importance for many applications including weather forecasting and offshore wind energy. Roughness parameterizations derived from different datasets are widely used but their performance is not sufficiently assessed under realistic marine environmental conditions. To this end, a multi-scale atmosphere–wave coupled model is constructed for the first time and used in the simulation of the MABL flow over the North Sea. Results show that our model is able to capture the large-scale variation of the mean wind meanwhile reproducing the appropriate turbulence energy cascade in the frequency domain. The performance of different roughness parameterizations is evaluated in comparison with the measurement data from the FINO1 platform. The Taylor-Yelland method outperforms the others on statistics of the mean wind while yielding the highest bias of the Turbulence Kinetic Energy (TKE) from the observations. However, we find that the discrepancy between our simulation and observation mainly depends on the meso-scale model. The magnitude of the differences caused by roughness parameterizations is negligible, especially in low wind speed conditions. The micro-scale simulation is demonstrated as not sensible to the roughness input in the considered wind–wave condition.

Review of Wind-Induced Effects Estimation through Nonlinear Analysis of Tall Buildings, High-Rise Structures, Flexible Bridges and Transmission Lines

The nonlinear effects exhibited by structures under the action of wind loads have gradually stepped into the vision of wind-resistant researchers. By summarizing the prominent wind-induced nonlinear problems of four types of wind-sensitive structures, namely tall buildings, high-rise structures, flexible bridges, and transmission lines, the occurrence mechanism of their nonlinear effects is revealed, providing cutting-edge research progress in theoretical studies, experimental methods and vibration control. Aerodynamic admittance provides insights into the aerodynamic nonlinearity (AN) between the wind pressure spectrum and wind speed spectrum of tall building surfaces. The equivalent nonlinear equation method is used to solve nonlinear vibration equations with generalized van-der-Pol-type aerodynamic damping terms. The elastic–plastic finite element method and multiscale modeling method are widely employed to analyze the effects of geometric nonlinearity (GN) and material nonlinearity (MN) at local nodes on the wind-induced response of latticed tall structures. The AN in blunt sections of bridges arises from the amplitude dependence of the aerodynamic derivative and the higher-order term of the self-excited force. Volterra series aerodynamic models are more suitable for the nonlinear aerodynamic modeling of bridges than the polynomial models studied more in the past. The improved Lindstedt–Poincare perturbation method, which considers the strong GN in the response of ice-covered transmission lines, offers high accuracy. The complex numerical calculations and nonlinear analyses involved in wind-induced nonlinear effects continue to consume significant computational resources and time, especially for complex wind field conditions and flexible and variable structural forms. It is necessary to further develop analytical, modeling and identification tools to facilitate the modeling of nonlinear features in the future.

A comparative study on the transient wind-induced response of long-span bridges subject to downbursts and typhoons

Inherent nonstationarity of the wind speed records is frequently captured during downburst and typhoon events, however, the significance of nonstationary effects on the bridge aerodynamics has not been widely investigated yet. In this study, the nonstationary wind-induced effects on aerodynamics under downburst and typhoon events were discussed. More specifically, the wind field input was generated using the instantaneous information embedded in the Hilbert spectrum, which was extracted from full-scale measurements of downburst and typhoon wind. The two-dimensional (2D) indicial response function was employed in the time domain buffeting analysis of a long-span bridge, and the transient effects on the bridge aerodynamics under downburst and typhoon were discussed. The results from the present study highlighted the significant transient nature of the downburst wind and its transient effects on the indicial response function, aeroelastic loads and buffeting response, while negligible transient effects under typhoon events.

Nudging Observed Winds in the Arctic to Quantify Associated Sea Ice Loss from 1979 to 2020

Abstract Over the past decades, Arctic climate has exhibited significant changes characterized by strong pan-Arctic warming and a large-scale wind shift trending toward an anticyclonic anomaly centered over Greenland and the Arctic Ocean. Recent work has suggested that this wind change is able to warm the Arctic atmosphere and melt sea ice through dynamically driven warming, moistening, and ice drift effects. However, previous examination of this linkage lacks a capability to fully consider the complex nature of the sea ice response to the wind change. In this study, we perform a more rigorous test of this idea by using a coupled high-resolution modeling framework with observed winds nudged over the Arctic that allows for a comparison of these wind-induced effects with observations and simulated effects forced by anthropogenic forcing. Our nudging simulation can well capture observed variability of atmospheric temperature, sea ice, and the radiation balance during the Arctic summer and appears to simulate around 30% of Arctic warming and sea ice melting over the whole period (1979–2020) and more than 50% over the period 2000–12, which is the fastest Arctic warming decade in the satellite era. In particular, in the summer of 2020, a similar wind pattern reemerged to induce the second-lowest sea ice extent since 1979, suggesting that large-scale wind changes in the Arctic are essential in shaping Arctic climate on interannual and interdecadal time scales and may be critical to determine Arctic climate variability in the coming decades. Significance Statement This work conducts a set of new CESM1 nudging simulations to quantify the impact of the observed evolution of large-scale high-latitude atmospheric winds on Arctic climate variability over the past four decades. Variations in climate parameters, including sea ice, radiation, and atmospheric temperatures are well replicated in the model when observed winds are imposed in the Arctic. By investigating simulated sea ice melting processes in the simulation, we illustrate and estimate how large-scale winds in the Arctic help melt sea ice in summer. The nudging method has the potential to make Arctic climate attribution more tangible and to unravel the important physical processes underlying recent abrupt climate change in the Arctic.

Numerical studies on aerodynamic forces and flow control regimes of square cylinder with four surface ribs

Façade ribs attached to building surface are effective in mitigating wind-induced effects. In this paper, LES approach is adopted to explore the impact of four surface ribs on aerodynamic forces and flow structure around a square cylinder with width D. ANSYS Fluent is used to carry out the simulations at Re=2.2 × 104, the standard sub-grid scale (SGS) model is used. Simulation results indicate that small vortices formed near ribs can remarkably suppress flow separation, and reduce the shear layer's curvature and periodic flapping. Facade ribs accelerate the vortex shedding process, and clearly reduce the wake vortices’ intensity. The change of the flow field clearly mitigates surface pressure with increase in rib extension depth dr, resulting in a clear reduction in wind forces. When the depth dr is greater than 0.06D, the variation trends of drag coefficient C¯D and lift coefficient C’L are relatively complex with change of rib location br. This is due to the significant changes of flow patterns with different rib configurations. The maximum reduction rates of C¯D and C’L are 61% and 82%. It is found that extension of rib dr from around 0.08D to 0.1D with distance to the corner br from about 0.16D to 0.2D may show the best performance in reducing wind load.

Wind-induced changes to shoaling surface gravity wave shape

Unforced shoaling waves experience growth and changes to wave shape. Similarly, wind-forced waves on a flat-bottom likewise experience growth/decay and changes to wave shape. However, the combined effect of shoaling and wind-forcing on wave shape, particularly relevant in the near-shore environment, has not yet been investigated theoretically. Here, we consider small-amplitude, shallow-water solitary waves propagating up a gentle, planar bathymetry forced by a weak, Jeffreys-type wind-induced surface pressure. We derive a variable-coefficient Korteweg-de Vries-Burgers (vKdV-B) equation governing the wave profile's evolution and solve it numerically using a Runge-Kutta third-order finite difference solver. The simulations run until convective prebreaking -- a Froude number limit appropriate to the order of the vKdV-B equation. Offshore winds weakly enhance the ratio of prebreaking height to depth as well as prebreaking wave slope. Onshore winds have a strong impact on narrowing the wave peak, and wind also modulates the rear shelf formed behind the wave. Furthermore, wind strongly affects the width of the prebreaking zone, with larger effects for smaller beach slopes. After converting our pressure magnitudes to physically realistic wind speeds, we observe qualitative agreement with prior laboratory and numerical experiments on breakpoint location. Additionally, our numerical results have qualitatively similar temporal wave shape to shoaling and wind-forced laboratory observations, suggesting that the vKdV-B equation captures the essential aspects of wind-induced effects on shoaling wave shape. Finally, we isolate the wind's effect by comparing the wave profiles to the unforced case. This reveals that the numerical results are approximately a superposition of a solitary wave, a shoaling-induced shelf, and a wind-induced, bound, dispersive, and decaying tail.

Couple simulations with CFD and ladybug + honeybee tools for green façade optimizing the thermal comfort in a transitional space in hot-humid climate

ABSTRACT Vertical gardens have become important strategies for urban heat island migration in recent years. However, the simulation tools for green façade (GF) with climbing plants coupling the shading and wind-induced effects are still lacked. This study focused on GF effects on human thermal comfort (HTC) optimization in a transitional space. The main purpose was to develop a couple method on HTC simulations. Field measurements in a hot-humid climate area were conducted to obtain the parameters of GF foliage layers. A couple simulation method with Ansys Fluent, Ladybug, and Honeybee tools was developed. Seven GFs layouts on a standard balcony model were simulated. In field measurements, the Ave. global irradiation was reduced by 73.29%, leaf area index was measured at 1.56–3.61, and foliage cover ratio was measured at 49.74–92.88%. In the simulations, the results of the Ave. wind velocity were reduced by 0.20–0.77 m s−1, the Ave. air temperature was reduced by 0.2°C, the Ave. mean radiant temperature was reduced by 0.5–7°C, and the Ave. physiological equivalent temperature was reduced by 0.3–3.2°C. The couple method could support the architectural and landscape design integrating with the GFs in future.

Machine learning based algorithms for wind pressure prediction of high-rise buildings

In recent years, machine learning (ML) techniques have been used in various fields of engineering practice. In order to evaluate the feasibility of machine learning algorithms for prediction of wind-induced effects on high-rise buildings, four ML algorithms including ridge regression, decision tree, random forest and gradient boosting regression tree are adopted in this study to predict wind pressures on Commonwealth Advisory Aeronautical Research Council standard tall building. The gradient boosting regression tree model is proved to be well performed in predicting both mean wind pressures and fluctuating wind pressures. Compared to expensive wind tunnel tests and time-consuming computational fluid dynamic simulations, it is expected that the gradient boosting regression tree model is an efficient and economical alternative for predicting wind pressures on high-rise buildings.

Microbarometer measurements to probe turbulent kinetic energy in the atmospheric boundary layer

Microbarometer networks are typically in place for the detection of atmospheric infrasound waves. The monitoring of such waves can be of interest for source characterization, which include a wide array of geophysical and man-made sources, as well as atmospheric infrasound propagation studies. In such studies, the presence of turbulence and other wind-induced effects are considered a nuisance. For this reason, wind noise filters are typically in place for suppression. As Cuxart et al. [BLM (2013)] pointed out, microbarometer measurements indeed have a value for detection of local and remote turbulence and measurements can be used to estimate turbulent kinetic energy (TKE). In this study, we compare microbarometer observations at the Cabauw atmospheric research site to co-located in-situ TKE measurements. Moreover, we compare turbulence timeseries to predictions from the high-resolution HARMONIE weather model in which this quantity is parameterized. This approach has two foreseen applications: (1) modeled TKE fields could possibly help in identifying regions that are most appropriate for infrasound monitoring due to low TKE values and (2) microbarometer observations could possibly be of use in the further refining of the modeled TKE parameter.

Estimation Formula of Modal Frequency of High-Rise Buildings under Different Wind Speeds during Typhoons

On 18 October 2016, the wind-induced effects of a high-rise building with square section was measured by the monitoring system in Haikou of China during Typhoon Sarika. The wind characteristics atop the building and the time-history responses of the translational and rotational accelerations on different floors were measured by the monitoring system; the first three modal parameters were identified according to the measured acceleration. The results show that the combinations of the cross spectral density function, phase spectrum, and coherence function can clearly judge the phase of the measured floors in the frequency resonance area as well as its modal frequencies at the first three orders. The modal frequencies at the first three orders decrease linearly with the growth of mean wind speed within the range of 0~20m/s. The estimation formula of the modal frequencies of high-rise buildings considering the influences of different wind speeds is put forward, which is expected to fill the gap in the existing specification for the quantitative analysis of the influences of wind-loads on the fundamental frequencies of high-rise buildings.

Horizontal vibration response analysis of ultra-high-speed elevators by considering the effect of wind load on buildings

Abstract. At present, the wind-induced vibration effects of super-high-rise buildings caused by wind loads can no longer be ignored. The wind-induced vibration effect of super-high-rise buildings will inevitably cause the vibration of ultra-high-speed elevators. However, for the study of the vibration characteristics of ultra-high-speed elevators, the wind-induced vibration effect of the ultra-high-speed elevator is often ignored. Based on Bernoulli–Euler theory, the forced vibration differential equation of elevator guide rail was established, and the vibration equation of elevator guide shoe and car was established by using the Darren Bell principle. The coupled vibration model of the guide rail, guide shoes, and car can be obtained through the relationship of force and relative displacement among these components. Based on the model, the effects of wind pressure and building height on the horizontal vibration of the ultra-high-speed guideway and passenger comfort were analyzed. The results showed that the influence of the wind load on the vibration of ultra-high-speed elevator can no longer be disregarded, and the maximum horizontal vibration acceleration of the guide rail is positively correlated with the height of building. The vibration acceleration of the same height rail increases with the increase in wind pressure. The vibration dose values (VDVs) increase with the increase in wind pressure and building height, respectively.

Nonlinear dynamic response analysis of buildings for wind loads. A new frontier in the structural wind engineering

The structural engineering practitioners often deal with natural hazards that generate a structural response that is dynamic in nature. The wind loads are long duration load types and their induced effects, especially for severe events, need to be predicted through analysis by efficient numerical nonlinear solvers. In this paper the nonlinear wind-induced effects on structures are predicted using a non-commercial software based on the 3D Force Analogy Method (3D-FAM). The wind loads consist of time-histories of pressure coefficients recorded at a large number of taps in the wind tunnel test for a model corresponding to an 80 m high prototype building. A considerable number of dynamic nonlinear analyses are performed for different mean hourly wind speeds and wind blowing directions. For each case, the inelastic behavior of building is monitored through and efficient complementary energy balance-based analysis and quantified in time-domain by damage indices at each section, element, story and structural level.

Influence of Wind-Induced Effects on Laser Disdrometer Measurements: Analysis and Compensation Strategies

Nowadays, laser disdrometers constitute a very appealing tool for measuring surface precipitation properties, by virtue of their capability to estimate not only the rainfall amount and intensity, but also the number, the size and the velocity of falling drops. However, disdrometric measures are affected by various sources of error being some of them related to environmental conditions. This work presents an assessment of Thies Clima laser disdrometer performance with a focus on the relationship between wind and the accuracy of the disdrometer output products. The 10-min average rainfall rate and total rainfall accumulation obtained by the disdrometer are systematically compared with the collocated measures of a standard tipping bucket rain gauge, the FAK010AA sensor, in terms of familiar statistical scores. A total of 42 rainy events, collected in a mountainous site of Southern Italy (Montevergine observatory), are used to support our analysis. The results show that the introduction of a new adaptive filtering in the disdrometric data processing can reduce the impact of sampling errors due to strong winds and heavy rain conditions. From a quantitative perspective, the novel filtering procedure improves by 8% the precipitation estimates with respect to the standard approach widely used in the literature. A deeper examination revealed that the signature of wind speed on raw velocity-diameter spectrographs gradually emerges with the rise of wind strength, thus causing a progressive increase of the wrongly allocated hydrometeors (which reaches 70% for wind speed greater than 8 m s−1). With the aid of reference rain-gauge rainfall data, we designed a second simple methodology that makes use of a correction factor to mitigate the wind-induced bias in disdrometric rainfall estimates. The resulting correction factor could be applied as an alternative to the adaptive filtering suggested by this study and may be of practical use when dealing with disdrometric data processing.

Numerical investigation of flow structures and aerodynamic interference around stationary parallel box girders

Many parallel bridges have been recently designed and built around the world to accommodate the ever-increasing volumes of vehicle and rail traffic. Accordingly, the aerodynamic interference around the parallel girders becomes important to investigate for a more accurate estimation of wind-induced effects on bridges. In this study, a wide range of gap-width ratios (0–15) for parallel box girders are selected to investigate the aerodynamic interference using three-dimensional large eddy simulation at zero wind attack angle. Specific aerodynamic characteristics, including the flow structures, pressure distributions, mean values and standard deviations of the force coefficients, Strouhal number as well as spanwise correlations of the aerodynamic coefficients are examined with various gap-width ratios. The detailed comparison work demonstrates a good agreement with the experimental work. The simulation results reveal that all the aerodynamic characteristics are significantly influenced by the gap-width ratio. The three regions are bounded by critical gap-width ratios of G/B = 0.25 and G/B = 5. There are large changes in behavior at G/B = 0.25, whereas, for G/B > 5, interference effects are not evident. The interference effects on both mean and fluctuating aerodynamic coefficients of parallel box girders are also quantified and summarized.

Effects of different day length and wind conditions to the seedling growth performance of Phragmites australis

BackgroundTo understand shade and wind effects on seedling traits of common reed (Phragmites australis), we conducted a mesocosm experiment manipulating day length (10 h daytime a day as open canopy conditions or 6 h daytime a day as partially closed canopy conditions) and wind speed (0 m/s as windless conditions or 4 m/s as windy conditions).ResultsMost values of functional traits of leaf blades, culms, and biomass production of P. australis were higher under long day length. In particular, we found sole positive effects of long day length in several functional traits such as internode and leaf blade lengths and the values of above-ground dry weight (DW), rhizome DW, and total DW. Wind-induced effects on functional traits were different depending on functional traits. Wind contributed to relatively low values of chlorophyll contents, angles between leaf blades, mean culm height, and maximum culm height. In contrast, wind contributed to relatively high values of culm density and below-ground DW.ConclusionsAlthough wind appeared to inhibit the vertical growth of P. australis through physiological and morphological changes in leaf blades, it seemed that P. australis might compensate the inhibited vertical growth with increased horizontal growth such as more numerous culms, indicating a highly adaptive characteristic of P. australis in terms of phenotypic plasticity under windy environments.