Wind Flow Direction Research Articles

Radionuclides' Dispersion from Coal-Fired Brick Kilns: Geo-Environmental Processes, Potential Risks and Management.

In order to investigate the distributions and possible dispersion mechanism(s) of naturally occurring radioactive materials (NORMs: 226Ra, 232Th, and 40K) from coal-based brick kilns, a systematic set (n = 60) of coal, ash, surface-soil, and subsurface soil samples were analyzed. High-quality analytical data of U, Th and K obtained from HPGe detector and TRIGA Mark-II research reactor-based neutron activation analysis were converted to the corresponding radioactivities. Average (n = 10) radioactivities of 226Ra, 232Th, and 40K in coal samples were 15.6, 16.7, and 145.5Bq.kg-1, respectively, where only 40K surpassed the corresponding global mean value. Average (n = 10) radioactivities of 226Ra, 232Th, and 40K in ash samples were 62.7, 88.5, and 521Bq.kg-1, respectively, where only 226Ra was within the established limit. In soil samples, average (n = 40) activities of 226Ra, 232Th, and 40K were 62.7, 95.1, and 641Bq.kg-1, respectively, which have surpassed the corresponding worldwide mean values. The observed differences in activity levels between soil samples collected near and far from the kilns, as well as between topsoil and subsoil samples, suggest the presence of distinct transport mechanisms for NORMs within the pedosphere. Dispersions of NORMs from the brick kilns to the ambient pedosphere are largely governed by aerodynamic convection and hydrodynamic leaching. These mechanisms are also influenced by geochemical mobility and relative solubility of NORMs, as well as factors such as rainfall patterns and wind-flow direction. Radiological indices invoke long-term carcinogenic-risks, whereas aerodynamic convection of finer particles (coal fly ash) from chimneys can cause significant health hazards to the nearby dwellers. Scientific processes as well as public awareness are essential to mitigate the risks.

Experimental investigation on wind loads and wind-induced responses of large-span flexible photovoltaic support structure

Flexible photovoltaic (PV) support structure offers benefits such as low construction costs, large span length, high clearance, and high adaptability to complex terrains. However, due to the high flexibility and low damping of the cable system, wind load becomes the primary control factor for structural safety and the key consideration in the design. In this study, a 45 m span flexible PV support structure with 3 spans and 12 rows was designed. The wind loads on PV panels were obtained by wind tunnel tests on a rigid model and the wind-induced responses were investigated by wind tunnel tests on an aeroelastic model. The shielding effects and tilt angle of PV modules on the wind load and wind-induced vibration of the flexible PV support were studied. The experimental results show that in the rigid model wind tunnel test, the wind pressure on the surface of PV modules exhibits a gradient distribution along the direction of wind flow, with symmetric distribution along the mid span. With the increase in the tilt angle of the PV module, the shielding effect becomes significant and the most pronounced shielding effect on the mean wind pressure coefficient occurs in the second row of the windward zone. In aeroelastic model wind tunnel tests, the mean vertical displacement of the flexible PV support structure increases with the increase of wind speed and tilt angle of PV modules. Due to the wind-resistant anchor cables set in both the windward and leeward zones, the vibration amplitude near the edge rows is significantly smaller than that of the middle rows when the structure is subjected to wind suction. When the flexible PV support structure is subjected to wind pressure, the maximum mean vertical displacement occurs in the first rows at high wind speeds. The shielding effect has a noticeable impact on the wind-induced response of the leeward zone at α = 20° under wind pressure, resulting in the decrease of amplitude vibration by approximately 53 %. The wind vibration coefficients in different zones under the wind pressure or wind suction are mostly between 2.0 and 2.15. Compared with the experimental results, the current Chinese national standards are relatively conservative in the equivalent static wind loads of flexible PV support structure.

Effects of open dumping site on surrounding air, soil, and water: a case study of Biratnagar metropolitan city

Managing solid waste is one of the emerging challenges in urban areas, and open dumping and burning is common practices mostly in developing countries like Nepal. Which affects the overall surroundings. The study has investigated the effects of open dumping and burning in nearby air, soil, and river water in dumping site of Biratnagar metropolitan city. For studying the effects on air, the three samples of air were taken, at center and 100m upstream and downstream to the direction of wind flow. Soil samples were taken at 10m from the dumping site center, at 25m from the first sample and at 60m from the second sample, and the water samples were taken at leachate and 100 m upstream and downstream to the leachate. Soil and water were subjected to the physiochemical test, heavy metals test and microbes test whereas PM 2.5, and PM 10 were tested for air quality. The results showed that the air from upstream has been seen carrying particulate matter from the dumping site to downstream. Similarly, it is found that the quality of water at leachate and downstream is degraded compared to upstream. The soil quality has been found to have degraded due to the harmful and toxic material of the dumping site. Thus, this study shows that open dumping and burning have affected the nearby air, water, and soil.

Analytical Simulation Approach to Evaluate the Ambient Humidity Effects on the Performance of a Wind Accelerator

Abstract The power production of wind turbines is experiencing an upward trend. However, on the other hand, the wind turbine’s performance slows down due to unseen changes in the environment. Humidity is one of the environmental factors affecting the performance of wind turbines. When humidity levels are high in the atmosphere, air is less dense. This air is lighter, and it results in reduced air pressure. A remedy to increase the air pressure in the direction of wind flow is to locate a wind accelerator, an aerodynamic device before the wind turbine to amplify the incoming wind speed and reduce the impact of humidity on the wind energy. This study intends to investigate the impact of environmental humidity on the performance of the wind accelerator. The study includes modelling the wind accelerator using Ansys 2023R1, to simulate different humidity levels. An analytical simulation is conducted to describe the aerodynamic behaviour of the wind accelerator in response to the changes in ambient humidity. The air at different percentage levels of humidity is passed through the proposed wind accelerator geometry to observe the wind speed variation and kinetic energy of the wind. The simulation study reveals that the wind speed and kinetic energy show higher values when the humidity is at a lower level, while the opposite is true when the humidity is higher. This emphasizes how important it is to consider all environmental elements while designing and developing wind turbines and wind accelerators for optimal performance subjected to various climatic conditions.

Examining Wind Flow's Impact on Multi-Storey Buildings: A Quest for Quality Improvement

Abstract This scientific article delves into the intricacies of wind flow's impact on multi-storey buildings, presenting results from a series of experimental investigations. The research encompasses an examination of wind interactions with buildings of varying heights and geometric profiles. Furthermore, it unveils the effects of tall structures on the natural ventilation and smoke evacuation systems of shorter edifices, considering different wind flow directions. The study leverages specialized wind tunnel and measurement techniques for a comprehensive analysis of wind-induced loads on buildings. The acquired insights furnish crucial input for the design of single-story temporary modular constructions within densely populated urban areas, subject to wind-induced stresses. Additionally, they hold potential applicability in the advancement of energy-efficient technologies and strategies within the realm of construction. The acquired dataset underscores the criticality of scrutinizing wind flow's impact on structures of varied typologies and dimensions and will allow to significantly improve the quality and efficiency of modern buildings in the future.

A 3D Parametric Venusian Bow Shock Model with the Effects of Mach Number and Interplanetary Magnetic Field

Using global magnetohydrodynamics simulations, we have developed a three-dimensional parametric model for the Venusian bow shock based on a generalized conic section function defined by six parameters, with the effects of the solar wind magnetosonic Mach number (M MS) and the interplanetary magnetic field (IMF) involved. The parametric model’s results reveal the following findings: (1) The size of the Venusian bow shock is primarily determined by M MS. An increase in M MS results in the bow shock moving closer to Venus and a reduction in its flaring angle. (2) Both the subsolar standoff distance and the bow shock’s flaring angle increase with the strength of the IMF components that are perpendicular to the solar wind flow direction (B Y and B Z in the Venus-centered solar orbital coordinate system), whereas the parallel IMF component (B X ) has a limited impact on the subsolar standoff distance but affects the flaring angle. (3) The cross section of the bow shock is elongated in the direction perpendicular to the IMF on the Y–Z plane, and the elongation degree is enhanced with increasing intensities of B Y and B Z . (4) The quasi-parallel bow shock locates closer to the planet as compared to the quasi-perpendicular bow shock. These findings are in alignment with prior empirical and theoretical models. The influences of M MS and IMF on the bow shock’s position and geometry are attributed to the propagation of fast magnetosonic waves, showing the nature of the formation of a collisionless bow shock under the interaction of magnetized flow with an atmospheric object.

Sistem for variable pitch vertical axis wind turbine

Climate changes and their effect worldwide point toward high need of renewable energy resources exploitation and, consequently, adequate policies on regulation for efficient energy consumption. Wind has been used since ancient times for producing energy and this is why research on wind turbine design and performances has been carried on since. This article is aimed to present new mechanical system for variable pitch vertical axis four blades wind turbine. The pitch angle varies depending on wind flow direction due to cam and follower, linked to a four bar mechanism.

Martian global current systems and related solar wind energy transfer: hybrid simulation under nominal conditions

ABSTRACT The magnetized solar wind drives a current system around Mars that maintains its induced magnetosphere. The solar wind also transfers its energy to the atmospheric ions, causing continuous atmospheric erosion, which has a profound impact on the planet’s evolution history. Here, we use Amitis, a Graphics Processing Unit (GPU)-based hybrid plasma model to first reproduce the global pattern of the net electric current and ion currents under an interplanetary magnetic field perpendicular to the solar wind flow direction. The resultant current distribution matches the observations and reveals more details. Using the electric field distribution characterized earlier with the same model, we calculate for the first time the spatial distribution of energy transfer rate to the plasmas in general and to different ion species at Mars. We find out that (1) the solar wind kinetic energy is the dominant energy source that drives Martian induced magnetosphere, (2) the energy flux of the shocked solar wind flows from the magnetic equatorial plane towards the plasma sheet in the induced magnetotail, (3) both the bow shock and the induced magnetospheric boundary are dynamos where plasma energy is transferred to the electromagnetic field, and (4) the planetary ions act as loads and gain energy from the electromagnetic field. The most intense load region is the planetary ion plume. The general pattern of the energy transfer rate revealed in this study is common for induced magnetospheres. Its variabilities with the upstream conditions can provide physical insight into the observed ion escape variabilities.

An orientation-adaptive electromagnetic energy harvester scavenging for wind-induced vibration

Wind energy is widely distributed, pollution-free and sustainable. Harvesting wind-induced vibration energy is a promising way to build self-powered systems. However, most of the current wind-induced vibration energy harvesters are unidirectional directional and insensitive to the frequently changing in wind direction. To overcome the difficulty, this work proposes an orientation-adaptive electromagnetic energy harvester (EMEH). By introducing a rotatable bluff body, the EMEH could be self-regulated to cater for the wind flow direction. Experimental results showed that the output power of the proposed EMEH could be enhanced greatly with the increase of rotatory inertia of the rotating bluff body. And, when the stiffness of the elastic beam is high, the output performance of the EMEH can be guaranteed by increasing the rotatory inertia of the rotatable bluff body. The output power of the optimized rotating bluff body and the elastic beam is 0.498 mW and 0.673 mW at wind speeds of 5.22 m/s and 8.0 m/s, respectively.

Influence of forest canopy structure and wind flow on patterns of sub‐canopy snow accumulation in montane needleleaf forests

AbstractVegetation structure is considered one of the most important factors shaping the spatial variation of snow accumulation under forest canopies. However, fine scale relationships between canopy density, snow interception, wind redistribution and sub‐canopy accumulation are poorly understood and difficult to observe, and their influence governing stand‐scale snow distributions that determine snow covered area depletion during melt is largely unknown. In this study, fine‐scale observations of forest structure and sub‐canopy snow accumulation were analysed over two mid‐winter snowfalls to a sub‐alpine forest in Marmot Creek Research Basin, Canadian Rockies, Alberta, to identify the impact of snow‐canopy interactions on spatial patterns of sub‐canopy snow accumulation. High spatial resolution (5 and 25 cm) snow accumulation estimates and canopy structure metrics were calculated from the combination of repeated UAV‐lidar observations with snow and photographic surveys, utilizing novel resampling methods including voxel ray sampling of lidar (VoxRS) to improve metric robustness and reduce bias. Over 50% of the spatial variance in forest snow accumulation was found at length scales less than 2 m, supporting the role of local scale canopy structure in governing variation in subcanopy snow accumulation. Additionally, subcanopy snow accumulation showed significant angular spread in relationships with overhead canopy structure; the vertical asymmetry coinciding with local windflow directions during snowfall. Detailed angular analysis showed nontrivial snow‐vegetation relationships that likely reflect multiple snowfall‐vegetation processes, including unloading and entrainment of intercepted snowfall during wind gusts and funnelling of entrained particles by downwind vegetation. These fine‐scale findings suggest several emergent processes which may influence snow accumulation at the scale of forest stands, with novel considerations for representing snow water equivalent distributions under dense evergreen canopies under varying environmental and canopy conditions. Similar studies over a broad range of conditions and forests will help refine and generalize the effects observed here for further snow hydrology and forestry applications.

STATISTICAL MODEL OF AERODYNAMIC IMPACT ON THE LARGE-SPAN COVERAGE

The aim of the study was to study the possibility of using the Dirichlet distribution as a statistical model of the process of dynamic interaction of large-span structures with aerodynamic load. As an object of research, a model of a hangar building was chosen for the maintenance of two AirbusA-380 aircraft at a scale of 1: 500 blown in a wind tunnel at five directions of wind flow at angles of 0 °, 30 °, 45 °, 60 °, 90 ° to the front of the structure ... It is shown that the statistical model of the Dirichlet distribution has sufficient flexibility and realism and compares favorably with the models built on the basis of the normal distribution, beta distribution, gamma distribution and Poisson distribution when describing the processes of intense dynamic interaction of wind load with structural elements. The problem of finding an integral assessment of the state of the processes of interaction of the wind load with the hangar building for the maintenance of two aircraft was reduced to calculating the self-organization parameter of the distribution over the surface of the building model of the aerodynamic coefficients, which was taken as the ratio of the total weighted amount of the Dirichlet models detected in the analyzed numerical series of the registered signal i-th dimension with negative external entropy to the total weighted number of Dirichlet models with positive external entropy.
 The study showed that the dimensionless informational and statistical indicator of self-organization makes it possible from a unified standpoint to assess the states that differ from each other in terms of external signs, the processes of interaction and their dynamics. The integral indicator can be used to rank the efficiency of operating systems and can be useful in assessing the state of the processes of dynamic interaction of the operating pressure and objects and structures of various shapes and purposes.

Four-wire orthogonal structure for accurate measurement of fluid velocity and wind flow direction using silicon micro-machining on silicon nitride membranes

Four-wire orthogonal structure for accurate measurement of fluid velocity and wind flow direction using silicon micro-machining on silicon nitride membranes

Simulasi WinAir4 (CFD) Terhadap Pengaruh Kecepatan Dan Aliran Udara Di Dalam Ruang Kuliah Universitas Nusa Nipa Maumere

Comfort can be provided from a building, inseparable from the existence of the building itself in the context of an environment that is limited by consideration of natural factors. In an effort to achieve comfort in buildings in tropical climates such as Indonesia, especially the city of Maumere, with characteristics of wind speed, humidity and relatively high air temperature and solar heat radiation can reach levels outside the human comfort zone. This study compares the speed and direction of wind flow in different lecture halls, seen from the level of height, direction and contour of the ground. The method used is data taken using equipment measured in the field and the results are simulated using WinAir4 from ECOTEC. The results obtained are the effect of altitude level, direction and contour orientation on wind speed and air flow in the design of the lecture hall in relation to thermal comfort.

EXPERIMENTAL STUDY OF SNOW LOAD DISTRIBUTION ON A SHELL OF THE GRAND SPORTS ARENA OF LUZHNIKI OLYMPIC COMPLEX

Introduction. The mechanism of the formation of snow deposits on the shell of the Luzhniki GSA and their redistribution in winter were established on the basis of the data obtained during the monitoring of the snow load for over 20 years.Aim. In this article, the mechanism of the formation of snow deposits and their distribution on the shell of the Luzhniki GSA were determined, along with the numerical values of the form factor μ characterizing the transition from the ground snow load to the snow load on the shell.Materials and methods. The measurements of the load and density of snow deposits on the shell of the Luzhniki GSA were carried out from 1998 to 2019. The obtained results were compared with the parallel measurements of ground snow load (GSL) in Luzhniki. In addition, the snow load, as well as statistical data analysis on the maximum annual values of the GSL, were analyzed using the hydrometeorological data of decadic snow surveys in Moscow, performed by the V.A. Mikhelson Meteorological Observatory following the dates of field measurements. The graphs of the repeatability of wind directions for the month preceding the observation dates were plotted.Results. The maximum values of the form factor μ for each section of the shell were obtained. The areas characterized by increased snow deposition on the shell during various periods of snow accumulation andthe dependence of their formation on wind speeds and directions in winter were revealed. Graphs depicting the distribution of snow load on the surface by observation years were plotted. It was established that the values of snow loads on the GSA shell during the observation period generally lay within the design values, except for local zones near the internal contour during the installation of the canopy.Conclusion. It was shown that the formation, accumulation, and redistribution of snow deposits on the shell comprise a complex and uneven process, varying from winter to winter. When selecting the analytical models of snow loads for calculating unique load-bearing structures, it is necessary to account for the most unfavorable wind flow directions, at which an uneven snow deposition pattern occurs, as well as the physical properties of the shell and field observations.

Increasing the wind power generation by modifying the windmill mechanism

The population-consuming resources are expanding by the day; the resources are mostly used in a limited fashion. As a result, a technique for connecting natural resources with growing populations is necessary. Wind turbine technology produces the highest power of any currently available renewable energy source, but it only converts energy into electricity in one direction of wind flow. Power creation is constrained since the current technique is intended to produce energy by receiving input from just one direction. This initiative aims to address this problem. This project's mechanism uses wind energy in both clockwise and counter-clockwise directions as input. Under perfect conditions, this system creates a lot more electricity than the existing traditional windmill system. This output is attained by changing the windmill's gearbox transmission system from a planetary gear system to a simple gear train system along with intermediate gear. As a consequence, if the wind blades allowed the two directional effects, then using this system the wind turbine blade's rotational position is reversed. Therefore, it can obtain an increase in power production by the recommended designed mechanism. These effects are analyzed by ANSYS Fluent software and the results are used to prove this increased output energy than the existing domestic windmills. In terms of electricity and energy conservation, this project shows a successful output.

Evidence for the Effects of Wind on the Biogeography of Soil Mites in Urban Tree Wells

The theoretical predictions of island biogeography have been applied successfully by a number of researchers studying the population and community structures of invertebrates living in large urban parks and remnant natural areas. Few, however, have examined the biogeography of smaller patches and the role that specific dispersal techniques play in shaping species distributions. In this study, I examine the impact of several biogeographical and environmental factors, including wind channelization effects, on the abundance of soil mites in small, urban tree wells in Westminster, Maryland. By testing five models that include the variables of well area, isolation, and dominate wind direction, I account for all possible directions in which channelization effects may be directing wind flow most frequently, therefore accounting for the impact of wind dispersal on mite distribution. As one would expect if mite abundances were impacted by the dominate direction of wind flow on a given street, only one of these models significantly explained the pattern of mite abundances found from sampling the tree wells. While the low power of the models requires that these results be viewed as inconclusive, the unusually high amount of variance explained by the significant model (R2 = 0.76), along with its agreement with better established biogeographical relationships, does suggest that future research into the role of wind as a factor in the biogeography of passively dispersing urban invertebrates may be worthwhile.

Risk-averse design of tall buildings for uncertain wind conditions

Reducing the intensity of wind excitation via aerodynamic shape modification is a major strategy to mitigate the reaction forces on supertall buildings, reduce construction and maintenance costs, and improve the comfort of future occupants. To this end, computational fluid dynamics (CFD) combined with state-of-the-art stochastic optimization algorithms is more promising than the trial and error approach adopted by the industry. The present study proposes and investigates a novel approach to risk-averse shape optimization of tall building structures that incorporates site-specific uncertainties in the wind velocity, terrain conditions, and wind flow direction. A body-fitted finite element approximation is used for the CFD with different wind directions incorporated by re-meshing the fluid domain. The bending moment at the base of the building is minimized, resulting in a building with reduced cost, material, and hence, a reduced carbon footprint. Both risk-neutral (mean value) and risk-averse optimization of the twist and tapering of a representative building are presented under uncertain inflow wind conditions that have been calibrated to fit freely-available site-specific data from Basel, Switzerland. The risk-averse strategy uses the conditional value-at-risk to optimize for the low-probability high-consequence events appearing in the worst 10% of loading conditions. Adaptive sampling is used to accelerate the gradient-based stochastic optimization pipeline. The adaptive method is easy to implement and particularly helpful for compute-intensive simulations because the number of gradient samples grows only as the optimal design algorithm converges. The performance of the final risk-averse building geometry is exceptionally favorable when compared to the risk-neutral optimized geometry, thus, demonstrating the effectiveness of the risk-averse design approach in computational wind engineering.

Experimental Analysis of Wind Pressure Characteristics in a Reduced-Scale Model of a Slab-Shaped High-Rise Building at Different Inflow Conditions with Various Wind Flow Directions

Wind resistance is one of the most important safety targets for high-rise buildings, especially slab-shaped ones with relatively large length–width ratios. In this study, the characteristics of wind pressure on a reduced-scale model of a slab-shaped high-rise building were analyzed experimentally. The experiment was conducted using the DTC Initium electronic scanning pressure measurement system in the wind tunnel at the Xiamen University of Technology, China. The spatial distribution and time-frequency characteristics of the wind pressure signals were analyzed with various wind flow directions under uniform and boundary-layer inflow conditions. The results show that both of the inflow conditions and the wind directions have significant influences on the magnitude and distribution characteristics of the wind pressure on the building surfaces. The wavelet transform-based analysis shows that the wind pressure on the building surfaces presents obvious intermittent characteristics, with the instantaneous energies pulsating intensively in the time-frequency domain, illustrating the unsteady nature of the wind pressure loads on the building. The influence and risk of the unsteady pulsating pressure loads should be considered when evaluating the wind-resistant performances of this type of building.

Interaction Between High-Rise Building, Wind and Pollution in District Twenty-Two of Tehran Municipality, Iran

<p>The large cities are facing with a phenomenon called high-rise buildings which is due to the increasing of the population and also developing the cities. One of the negative impacts of high-rise buildings is the change in urban wind flow. Air pollutions is a major problem in the cities and the wind play an important role in the dispersion of air pollutions. The most probable wind direction for Tehran is west and hence district twenty-two of Tehran municipality which is located in northwest of Tehran (Capital of Iran) is in the dominant direction of wind flow. This paper presents a numerical method to investigate the interaction between the wind flow, pollution and high-rise buildings in district twenty-two of Tehran municipality. The effect of these phenomenon on the other regions is considered as well. Computational fluid dynamics (CFD) by ANSYS Fluent software has been used in order to simulate the problem. The results of this study indicate the existing buildings and their layout had no effect on wind velocity and trapping the pollution and do not cause an increasing of the local concentration of pollutants. So the geometry and layout of buildings allow the flows and environmental pollutants to pass.</p>

Wind loading and its effects on photovoltaic modules: An experimental–Computational study to assess the stress on structures

Photovoltaic modules are one of the intensively used technologies that provide a renewable energy alternative to electricity generation. Consequently, these devices have been studied using different approaches in order to determine their aerodynamic characteristics. Nevertheless, there is still a lack of guidelines from the codes of practice that could enable users and manufacturers to chose/recommend different types of photovoltaic modules according to siting and operation conditions.In order to provide more data about the influence of the photovoltaic module aerodynamics on its constitutive structural elements, an interdisciplinary approach is advisable. In this study the subject is addressed through experimental measurements and numerical assessment of a standard photovoltaic module under different conditions. Boundary layer wind tunnel tests were performed to determine wind loads over ground mounted photovoltaic modules, considering two situations: stand-alone and forming an array of panels. Several wind directions and inclinations of the photovoltaic modules were taken into account in order to detect possible wind load combinations that may lead to a condition not prescribed by the codes of practice. All tests were carried out using rigid models of the photovoltaic modules, that is, the experimental analysis is limited to static wind tunnel testing. A detailed numerical evaluation is performed using the finite element method (FEM) to identify critical structural sections. For the stand-alone case, the most influential wind flow directions correspond to oblique directions for local pressures and along wind direction for overall forces. For the case of the photovoltaic module array, it is observed that the wind loading over the leading panels is decisive for the design. According to the numerical results, the central support device is the most critical structural component.