Wind Chill Research Articles

Investigation of Torque and Reduction of Torque Ripples through Assisted-Poles in Low-Speed, High-Torque Density Spoke-Type PMSMs

In this article, rotor designs utilizing assisted-poles are investigated for a high-torque density spoke-type permanent magnet synchronous machine (PMSM) with fractional slot concentrated winding (FSCW) to explore the rich air-gap magnetic field harmonics and torque generation mechanism. Due to their higher average torque output, spoke-type PMSMs with FSCW are increasingly used in high-torque density applications. However, slot harmonics generate torque ripples that are difficult to eliminate in FSCW spoke-type PMSMs. Removing slot harmonics from the stator or winding results in a large drop in torque since their winding factors are identical to those of the main harmonic. Therefore, rotor designs having assisted-poles (symmetrical and asymmetrical) are investigated in this work to mitigate slot harmonics and minimize torque ripples. Firstly, the air-gap flux density is analyzed for the machines having assisted-poles, and a model of interaction between the stator and rotor-MMF harmonics is created and validated through Finite element analysis (FEA) to analyze the torque production mechanism. In addition, an analytical relationship between the assisted-poles’ dimensions and the generated torque harmonics is proposed. Furthermore, a generalized torque ripple reduction concept for the FSCW spoke-type PMSM having asymmetrically designed assisted-poles is presented. The proposed design and optimization method are validated through analytical calculations and FEA simulations, and a brief comparative analysis is presented for the analyzed machine prototypes. It has been established that the machine designed by applying the proposed asymmetrical assisted-poles can achieve a reduction in torque ripples while also significantly lowering cogging torque in comparison to the conventional spoke-type PMSMs and other spoke-type PMSMs with rotor having symmetrical assisted-poles.

Wind-urban structure interplay in PM2.5 variation: Insights from multi-seasonal mobile air quality campaign

The health risks associated with particulate matter pollution (PM2.5) highlight the importance of comprehending key drivers of its spatial and temporal variability. While explanatory modeling is widely used for statistical inference in such applications, the role of wind variables (speed, direction) and their interplay with built environment are often overlooked. This study addresses this gap through a mobile air quality campaign in a suburban area over 10 days for each of three distinct seasons. We developed four innovative wind-based buffers to account for the wind factors and assess the impact of LiDAR-derived 3D built environment structure on PM2.5 variability at local and regional scales. Our second objective is to assess the predictive capabilities of wind-based variables. Results indicate that in our low-elevation, low-rise building study area, the built environment does not emerge as a significant factor, contrary to findings in larger, denser urban areas. Wind direction proves more effective in capturing concentration fluctuations than wind speed, and its interaction with pollution source orientation can change pollution dynamics. This study introduces new insights and methodologies for incorporating wind-related factors into the analysis of air pollution dynamics, offering opportunities for further investigation in various urban settings.

The analysis of the factors influencing the operation of the piston wind in the cage of the hybrid hoisting shaft and the simulation study of the operation effect

The mixed shaft in the mine is used as the main inlet and return air shaft and also as the lifting shaft. The piston wind effect caused by the frequent operation of large and efficient lifting equipment in the shaft will disturb the normal air flow in the shaft and cause the air flow disorder. So It is important to study influencing factors and the series of piston effects of inner cage operation in the hoisting shaft. This paper firstly derives a theoretical model of piston wind for double cage operation in a wellbore based on the non-constant flow theory of Bernoulli’s equation, and derives the influencing factors of piston wind. Then, according to the actual situation of the mine, a 3D fluid simulation model of cage hoisting is established. Based on the verified simulation method, the transient division of labor of piston wind effect and its influencing factors is simulated and the influence of various factors on the development law of piston wind is analyzed in detail. The study results show that the main factors influencing the piston wind are the cage operating conditions, the cage operating speed, the shaft blockage ratio and the initial ventilation speed in the shaft. The operation of the cage produces an eddy current zone, which causes air flow disorder in the wellbore and affects the ventilation effect of the shaft. The piston wind speed is the highest when the cage running against the wind, while the speed is lower running with the wind. The most complex wind flow disturbance occurs when the two cages meet, which is almost block the flow of wind in the shaft. The change of cage operating speed and wellbore blockage ratio is related to the piston wind speed and pressure changes linearly in different conditions. There is the best blockage ratio between the hoisting cage and the shaft, which can cause the highest average ventilation speed in the shaft, and the best blockage ratio of the study model is 0.32.

Calculation of Kinetic Fractionation of Open‐Water Evaporation Over an Upland Reservoir

AbstractBased on the fact that many water reservoirs built in headwater catchments receive no water input during dry season, we modified the Craig‐Gordon model and proposed an approach to calculate kinetic fractionation factors in open‐water evaporation taking into account isotopic compositions of precipitation and of lake water, lake volume, and land‐based meteorological data. The approach is centered around the determination of lake water isotope enrichment rate over time during dry periods. We then applied this approach for calculating kinetic fractionation factors, turbulence index, and open‐water evaporation for a small reservoir located in a sub‐tropical monsoonal climate. We found that the kinetic fractionation factors, εK,H and εK,O are, respectively 3.11‰ ± 0.41‰ and 2.50‰ ± 2.15‰, corresponding to the turbulence index of 0.43 ± 0.19. Evaporation rates in open‐water estimated by our approach is 1.55 times of the land‐based evaporation gauged in the nearby meteorological station. Wind speed, represented by turbulence index, is proved as an important climatic factor influencing kinetic fractionation. This study confirms that wind and surface area factors, which have been neglected in several isotope mass balance models, should be included into calculation process.

Numerical simulation of the slamming effect of regular waves and freak waves on ultra heavy-lift amphibious connector

The Ultra Heavy-lift Amphibious Connector can be used for sea and land operations. When the amphibious connector opens the bow door, it will inevitably suffer from the combined action of wind, waves, currents, and other factors, resulting in the slamming of the wave on the hatch and various landing ship hull movements in the process. Due to the complexity of the actual UHAC model, in order to save computing resources, this paper selects the external load on the UAHC hatch when it is operated in water when the door is closed. The effects of crest height, draught, and focus position on UHAC slamming under the action of regular waves and freak waves were analyzed. Based on the viscous flow theory, the CFD commercial software FLUENT is used to simulate the interaction between the reduction of regular waves and floating structures. The simulation results are compared with the experimental results to verify the feasibility of the proposed method. Since the published UHAC data cannot be found in the network environment, this paper draws the UHAC based on the only data on the Internet and studies the slamming load of the wave on the UHAC on this basis.

Decarbonising mining of Australia's critical mineral deposits: Opportunities for sustainable mining through solar photovoltaics and wind energy integration

Critical minerals are essential in numerous industrial applications, particularly those related to green energy production. Nonetheless, the mining and processing of these minerals are severely energy-intensive, relying predominantly on diesel, coal, and gas as sources of power in Australia. Consequently, the use of diesel, coal, and gas as power sources results in a substantial carbon footprint. An important research gap that remains to be explored in the Australian mining sector is investigating the potential for decarbonising the mining of critical minerals through the implementation of renewable energy to attain sustainable mining. This study examines the potential of using solar photovoltaics (PV) and wind energy towards the decarbonisation of critical mineral deposits, taking into account both the intrinsic mineral characteristics such as ore grade, ore depth, and co-existing mineral clusters, as well as external factors such as the capacity factor (CF) and the periods of low energy generation (lull times) of solar PV and wind, which are crucial in assessing the availability of the renewable energy sources explored. The results from this study indicate that a considerable number of critical mineral deposits in Australia are remotely located from the existing national transmission line infrastructure. These deposits often form geographical clusters and typically have favourable conditions for solar PV and wind energy implementation, characterised by high capacity factors and minimal lull times in solar PV/wind. This clustering presents a promising opportunity for powering mining activities with solar PV and wind energy, thus facilitating the decarbonisation of mining operations in Australia through the utilisation of shared renewable energy infrastructures. Moreover, the study identifies specific mineral deposits that are most suitable for decarbonisation with solar PV and wind energy integration. The research method used in this study proposes an evaluative framework that correlates the capacity factor of solar PV and wind with lull times from these sources, as well as with mineral intrinsic characteristics within deposits. This framework enables a comparative analysis of different deposits, assessing their relative suitability for the integration of solar PV and wind energy technologies. This framework is versatile and can be employed to assess different renewable energy sources, making it applicable to various global contexts. The findings from this study underscore the transformative potential of renewable energy sources, indicating that solar PV and wind energy offer new opportunities for attaining decarbonised and sustainable mining in Australia.

The impact of some environmental variables on the performance of solar PV module

The country of Iraq tops the list of countries in solar activity and therefore has the most important renewable energy sources, which we desperately need to fill the acute shortage of electrical energy. The availability of this source coincides with a significant rise in temperature in most of its regions and a wide range of days of the year. Where temperatures play a key role in wind activity and the provocation of dust storms, which urgently requires a field study to find out the impact of these factors on the performance of photovoltaic solar modules. Therefore, this study aimed to evaluate the performance of the solar module under the influence of dust accumulation, temperature and wind speed. A group symmetric of monocrystalline silicon solar modules have been experimented to see how these factors affect the performance of the modules. The results showed that there is a clear impact by the heat factor and dust accumulation on the performance of solar modules, but the wind factor is the least influential and what can be concluded is that Iraq, especially the city of Baghdad, is an ideal place to invest solar energy in the production of electrical energy.

Bio-logging reveals heritable patterns of natural behaviours in sheep

The measurement of behaviour in extensively managed livestock for the assessment of welfare remains a challenge. Bio-logging devices offer the opportunity to collect continuous behavioural data over long periods while animals are in their normal physical environment. Using collar-measured acceleration from 84 ewes over 28 days in a commercial flock, we built two-component daily phenotypic profiles with data-driven analysis techniques not reliant on human observations. Our analysis demonstrates the moderate repeatability of both components (0.58 ± 0.06 and 0.53 ± 0.05), the heritability of one component (0.53 ± 0.15), and environmental associations with wind chill index (−0.63 ± 0.13), and day length (−0.66 ± 0.19). We discuss these results in relation to previous work, showing that our methods of measurement and analysis are capable of revealing the daily patterns of behaviour in sheep and how these are influenced by the physical environment and genetics. This approach can be generalised to assess behavioural phenotypes and the determinants of behaviour in other breeds or species.

Analysis and Preliminary Design of Variable Flux Reluctance Machines: A Perspective from Working Field Harmonics

Variable flux reluctance machines (VFRMs) are increasingly attracting research interest due to their magnetless and robust brushless structure. Under the modulation effect of the airgap permeance, the VFRM operates with a series of field harmonics, distinguishing it from conventional AC synchronous machines. This paper deals with the analysis and preliminary design of the VFRM from the perspective of multiple working airgap field harmonics. Firstly, the spatial and temporal order of the working field harmonics are defined. The systematic winding theory, including the unified star of slots and winding factor calculation method, is established to consider all these working harmonics. Then, an average torque model is built and simplified. The key role of 1st-order rotor permeance, 1st- and 3rd-order polarized stator permeance is deduced. The relationship between key parameters and average torque is computed, providing a guideline for the preliminary design of the VFRM.

Experimental effect of wind and heavy rain on increased splash erosion using rainfall simulator

To investigate the erosion process that occurs, rainfall simulation is used with a model scale for natural rain events in laboratory conditions. The calculation of erosion and any soil erosion with a slope setting of 5% was carried out experimentally on a laboratory scale using a rain simulator and adding wind using a 2-inch snail blower. Experiments carried out in the laboratory included erosion tests driven by rain and erosion tests by rain, which were given additional wind variables. Rain intensity used for testing is using discharge 1 litre/minute,1.5 litre/minute, and 2 litre/minute as a representative variation of rainfall. The occurrence of rain and wind simultaneously within a certain period will cause greater loss of soil. Although many studies have been conducted on the effects of rain and the combined effects of wind on soil erosion, only a limited number of studies have focused on the combination of the two variables that occur together. The results showed that in the applied rain intensity and wind factor, the collision of the kinetic energy of the rain driven by the wind resulted in higher erosion when compared to that without the influence of the wind.

The Evaluation of the Impact of Meteorological and Marine Environment on the Combat Effectiveness of Surface Ships

In recent years, the evaluation of the impact of meteorological marine environment on the combat effectiveness of surface ships has been an important content and hot topic in military oceanography research and naval battlefield support. In this paper, the analytic hierarchy process is adopted to establish the hierarchical structure of the evaluation model, determine the weights of each index, and quantitatively evaluate the proportion of the influence of wind, sea wave, rain, visibility, atmospheric waveguide, and other factors on the combat effectiveness of surface ships. Combined with marine hydrometeorological data examples, fuzzy comprehensive evaluation method is used to evaluate the index system, which can provide scientific and reasonable decision-making reference for ship commanders.

ЧИСЛЕННОЕ МОДЕЛИРОВАНИЕ ВРЕМЕННЫХ РЯДОВ БИОКЛИМАТИЧЕСКИХ ИНДЕКСОВ В АРКТИЧЕСКОЙ ЗОНЕ РОССИЙСКОЙ ФЕДЕРАЦИИ НА ОСНОВЕ СТОХАСТИЧЕСКОГО “ГЕНЕРАТОРА ПОГОДЫ”

The paper proposes an approach to the numerical stochastic modeling of the time series of the wind chill index and equivalent effective temperature at weather stations located in the Arctic zone of the Russian Federation. The approach is based on the use of a specially designed stochastic weather generator. It is shown that the approach allows developing the models of the time series of bioclimatic indices that very accurately reproduce various statistical properties of real processes related, in particular, to their daily variations and specific features of the study area.

TWO-CHANNEL BALLISTIC TRANSFORMER GRAVIMETER

The two-channel ballistic transformer gravimeter for measuring the doubled value of the acceleration of gravity contains a gravimeter that uses a fixed glass tube made of a dielectric material, a magnetized test body in the form of a layer, a computer and an inductance winding, which is characterized by the fact that the fixed tube is made of a dielectric material, the inductance winding acts as a primary excitation winding connected to the power source, which additionally contains two identical sections of the secondary output winding, connected in series-opposite, to create two measurement channels, an electromagnet consisting of an armature made of magnetic material, an additional winding connected through a switch to an additional power source. To provide free vertical movement in two opposite directions along the OZ axis of the magnetized test body, it is proposed to use the proposed electromagnet consisting of an armature made of a soft magnetic material, an additional winding connected through a switch to an additional power source. The winding of the electromagnet is connected to the power source by a switch to create an electromagnetic flux of attraction to the test body, which, thanks to this, will rise to the uppermost position. At the next moment, the electromagnet switch is turned off, and the test body falls down under the action of the acceleration of gravity. The doubled output signal of the acceleration of gravity, which is removed from the secondary winding, is free from the effects of interference: external electromagnetic flows, inertial vertical acceleration, instrumental errors caused by changes in temperature, humidity, vibrations, pressure, the moment of dry friction forces, non-identity of the parameters of two identical sections of the secondary output winding and other factors - is submitted to the computer. The output of the computer is proportional to twice the acceleration of gravity value. Increased accuracy and reliability of measurements of the doubled value of the acceleration of gravity and increased efficiency of the search for minerals have been ensured

Frostbite incidence is a selective term and dependable on methodology — a narrative review

Introduction: Frostbite is freezing of the tissue that mostly affects skin but also the underlying tissues. It results from prolonged exposure to temperatures below the freezing point of water (0°C). One of the many consequences of climate change is extreme cold events, which increase the risk of frostbite in the general population, particularly among individuals who are involuntarily exposed to cold for prolonged periods of time. Although frostbite has been a known phenomenon for a long time, occurring as early as 5000 years ago, the exact incidence of frostbite is not known. This is partly due to variable internal (frostbite susceptibility, hydration status, protective garments) and external etiological factors (wind chill, precipitation, altitude), that never coincide all at the same time. Objectives: The objective was to compare the incidence rates of frostbite in the published studies that focused on frostbite incidence. Methods: Out of a total of 61 studies using the keywords “frostbite” and “incidence” on PubMed, we selected seven that dealt with frostbite incidence over 20 years. We briefly summarized and compared the results of the studies. Results: The comparison of the seven studies shows a great variability of frostbite incidence depending on the population, its size, and the method of data collection. Studies that included civilian populations have significantly lower frostbite incidence rates than studies focusing on individuals who are exposed to temperatures below 0°C for extended periods, such as mountaineers, military personnel, workers in cold storage houses or homeless people. The results highlight different incidence rates for different populations and indicate that retrospectively collected data are insufficiently comparable among studies. Frostbite incidence, expressed as the ratio of injured individuals to non-injured inhabitants, is only comparable in studies using the same methodology. Enhanced frostbite susceptibility is a confirmed fact and was generally not considered in most of the studies. Conclusions: Frostbite incidences of the included studies are insufficiently comparable to draw any conclusions on possible general frostbite incidence in a population. To enhance our ability to estimate or predict frostbite occurrences within the general population, establishing an international or national frostbite registry in high-risk countries could be helpful.

Enhancement of carbon sink in the main marginal sea ice zone by cold season Arctic cyclones

The Arctic Ocean, as a significant carbon sink, is attracting increased attention within the scientific community. This study focused on the main marginal sea ice zone, which has been the most sensitive to environmental changes in recent decades. Using data from reanalysis, models, and on-site observations, the changes in air–sea CO2 flux (FCO2) were analyzed during the influence of Arctic cyclones (ACs) in 2021–2022. Results indicated that the passage of ACs tended to increase the average carbon sink in the main marginal ice zone, with a more pronounced effect during the cold season. During ACs, the average FCO2 could reach −6.95 mmolC m−2 d−1. This was mainly associated with the stronger and more concentrated distribution of ACs where there was lower pCO2 (air–sea gradient of CO2 partial pressure) in the cold season. Additionally, the change in FCO2 during ACs was primarily affected by the sea surface wind and sea-ice concentration in the cold season, while it was influenced by a variety of environmental factors in the warm season, including the sea surface wind, sea-ice concentration, and ecological factors.

The renewable energy sources impact on vernacular architecture’s ability to be built sustainably: case study of Rumah Gadang

Rumah Gadang has the physical appearance of traditional architecture and was founded on human interaction with the environment. The natural resources of each area in Indonesia are said to have the greatest environmental effect on traditional vernacular architecture. Rumah Gadang is prominent for its ability to successfully combine elements of sustainability with a variety of other factors, including the environment, aesthetics, and social character. However, only a few studies discuss sustainability elements combination within Architecture Nusantara, Rumah Gadang. Therefore, this study will aim to reveal how these elements affect the sustainability of Rumah Gadang and how they contribute to the development of regional architectural styles. The qualitative method was used in this study with literature studies followed by descriptive analysis. The result of the study indicates two things, 1) The nature of these elements’ characteristics in Rumah Gadang fit with social, and environmental sustainability standards. 2) The descriptive analysis reveals that the impact of the variations in natural energy sources on these elements’ characteristics in Rumah Gadang is reflected in its physical appearance. The findings shown that Rumah Gadang’s architectural elements, including the Gonjong roof, wall linings, raised floor, openings, and stone foundation, respond to renewable energy sources based on sun, wind, and humidity factors. Rumah Gadang fulfills three pillars of sustainability: Social sustainability is achieved through traditional values and Minangkabau culture, while economic sustainability is achieved through regionally produced materials and construction methods. Lastly, the primary goal is to offer thermal comfort with minimal waste, making environmental sustainability the most crucial outcome component.

Two-year wind field measurements near the ground at a site of the Tibetan Plateau

A nearly two-year wind field measurement in the plateau has been conducted in the south of Tibet. High-frequency anemometric data of the distinctive plateau wind field was obtained. Combining the non-stationary model and test, wind samples are classified into three types of 10-min samples based on the level of stationarity. Analysis reveals the strong non-stationarity, turbulence intensity, gust factor, and integral length scale of the synoptic wind in the plateau, which differ from the ones at low altitudes. The stationary samples are recommended to represent the plateau synoptic wind for characterizing the fluctuating wind. At smaller time scales, high-frequency records capture some intense gust events. Based on the different influences of wind on the structures from the perspective of structural wind resistance, the plateau transient intense gust events are divided into thunderstorms and front, and short-rise-time gusts. Representative gust events are defined, sifted, and extracted. With the combination analysis of 10-min fluctuating wind characteristics and intense non-stationary gust events, the measurement data assist the structural wind-resistance design in the plateau.

Green Heat and Wind Factors in Sustainable Urban Development of Mountain-Basin Relief

The article studies mountain basin relief’s influence on the heat and wind regime organization when developing it for sustainable urban planning purposes. Each time a unique relief is identified, it requires an individual design approach taking into account the identification of the aesthetic expressiveness of green settlement development. Depending on the slope, there may be different options for using the site. The article presents the features of the geometry of the mountain-basin space associated with the relative depth of the mountain basin. The thermal field of the mountain-basin space, which is formed due to the energy of incoming solar radiation and the internal heat of insolated urban development, is analyzed. The city’s mountain-basin terrain requires an individual design approach, taking into account the identification of the aesthetic expressiveness of green settlement development. Based on the generalization and analysis of studies of air flows’ structure, their direction, velocity, and temperature fields, as well as the characteristics of the microclimate in the development of the mountain-basin space, an aerodynamic picture of air movement arising under the influence of natural thermal forces was obtained. The thermal field of the mountain-basin space has been established, which is formed due to the energy of incoming solar radiation and the internal heat of insolated urban development. The proposed methodology for calculating the heat and wind conditions of development is the basis for preliminary forecasting, assessment, and regulation of heat and wind parameters, as well as optimization of the sustainable development planning of mountain-basin relief.

Performance Assessment of Overhead Conductors Subjected to Combined Thermal and Wind Loads

The overhead power conductors carry electricity power from distribution feeders to consumers, providing a necessary service. Aluminium Conductor Steel Reinforced (ACSR) and All Aluminium Conductors (AAC) are widely utilised in the Australian power distribution network. ACSR offers increased strength and conductivity by combining both steel and aluminium strands while AAC offers proper conductivity and lightweight powerlines. Due to factors like current flow, extremely elevated ambient temperatures, direct sunlight exposure, and short circuit currents, these conductors can be subjected to elevated temperature levels. Operating at higher temperatures can alter the mechanical characteristics of the conductor materials. Consequently, the mechanical strength of conductors diminishes when powerlines consistently operate under these conditions. Conductors are set up in various environmental conditions, resulting in different wind load impacts. While the temperature rise can be somewhat offset by these wind variations in terms of cable strength, wind action still introduces additional tensile stress in the conductor. Hence, this research aims to determine the combined effects of thermal and wind factors in the performance of ACSR and AAC cables. The laboratory experimental testing was performed to determine the decrease in the tensile strength of conductors under steady-state elevated temperature scenarios. The Australian standard prediction for wind and thermal conditions is considered for the calculation of the required strength in the conductors. Finally, the long-term safety performance of both ACSR and AAC cables was evaluated by considering the combined effect of temperature and wind effects.

Climatic and bioclimatic conditions at high-altitude meteorological stations in the Carpathian Mountains and the Sudetes in years 2005–2022

The subject of the analysis were the climatic and bioclimatic conditions of the mountainous areas in Central Europe from 2005 to 2022. The study was conducted based on meteorological data from 4 stations located in 2 mountain ranges in Central Europe, which were obtained from the Ogimet database. The analysis examined the course of mean air temperature, winter days, precipitation, snow cover, wind speed, horizontal visibility, as well as the number of days with thunderstorms and fog. Subsequently, bioclimatic indices were analyzed based on the wind chill index (WCI) and the climate severity index by Osokin (So). The results confirm an increase in mean air temperature and a decrease in the number of winter days. The most significant change in mean annual air temperature was recorded at the Carphatian stations: Varful Omu (0.59 °C/10 years) and Łomnica (0.49 °C/10 years). The largest change in the WCI value was recorded at the Carpathian station Varful Omu (51 W/m2 /10 years), while the So index was 1.4/10 years.