Literatura académica sobre el tema "Urban winds"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte las listas temáticas de artículos, libros, tesis, actas de conferencias y otras fuentes académicas sobre el tema "Urban winds".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Artículos de revistas sobre el tema "Urban winds"
1
Britcher, Colin P., John M. Wells, Benoit Renaud y Thibaut Buvat. "Aerodynamics of Urban Maglev vehicles". Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit 226, n.º 6 (20 de marzo de 2012): 561–67. http://dx.doi.org/10.1177/0954409712441740.
Texto completoResumen
Some aerodynamic issues affecting low-speed Urban Maglev vehicles are studied, focusing primarily on the effect of ambient winds on levitation electromagnet loads. Aerodynamic characteristics of a representative vehicle are estimated by means of wind tunnel tests of a 1/12th scale model. The wind environment influencing the existing Maglev guideway at Old Dominion University are established from historical data. It is shown that ambient winds, particularly crosswinds, can pose significant challenges, including substantial redistribution of levitation forces among vehicle electromagnets. The development of large lateral forces, particularly at the forward electromagnet stations, may also be of concern.
2
Romanic, Djordje, Ashkan Rasouli y Horia Hangan. "Urban wind resource assessment in changing climate: Case study". Wind Engineering 41, n.º 1 (1 de agosto de 2016): 3–12. http://dx.doi.org/10.1177/0309524x16653486.
Texto completoResumen
Urban wind resource assessment in changing climate has not been studied so far. This study presents a methodology for microscale numerical modelling of urban wind resource assessment in changing climate. The methodology is applied for a specific urban development in the city of Toronto, ON, Canada. It is shown that the speed of the southwest winds, that is, the most frequent winds increased for .8 m s−1 in the period from 1948 to 2015. The generated wind energy maps are used to estimate the influences of climate change on the available wind energy. It is shown that the geometry of irregularly spaced and located obstacles in urban environments has to be taken into consideration when performing studies on urban wind resource assessment in changing climate. In the analysed urban environment, peak speeds are more affected by climate change than the mean speeds.
3
Kim, Hyungkyoo y Elizabeth Macdonald. "Wind and the city: An evaluation of San Francisco’s planning approach since 1985". Environment and Planning B: Urban Analytics and City Science 44, n.º 1 (28 de julio de 2016): 10–32. http://dx.doi.org/10.1177/0265813515607474.
Texto completoResumen
In 1985, San Francisco adopted a downtown plan on ground-level wind currents intended to mitigate the negative effects of wind on pedestrians’ perceived comfort in public open spaces. The plan mandates that new buildings in designated parts of the city associated with high density or development potential be designed or adopt measures to not cause wind in excess of accepted comfort levels. This study examines whether and to what degree the plan has successfully shaped an urban form that mitigates wind by comparing the ground-level wind environment in 1985 and 2013. A series of wind tunnel tests found that during San Francisco’s windiest season when the westerly winds are prevalent, the overall mean wind speed ratio measured at 318 locations in four areas of the city dropped by 22%. However, there still exist many excessively windy places that are associated with specific urban form conditions, including streets oriented to have direct exposure to westerly winds, flat façades on high-rise buildings, and horizontal street walls where building façades align. Recommendations based on the findings include incorporating more tangible guidance on the built form conditions, expanding the plan’s reach to cover more parts of the city, and learning from strategies used elsewhere. By evaluating the urban form impacts of a wind mitigation policy that has been in place for 30 years, the research offers insights for other cities that have implemented or plan to adopt similar approach and sheds light on issues related to wind comfort in high-density urban areas.
4
Moreira, Davidson Martins y Taciana Toledo de Almeida Albuquerque. "Solution of the Atmospheric Diffusion Equation with Longitudinal Wind Speed Depending on Source Distance". Revista Brasileira de Meteorologia 31, n.º 2 (junio de 2016): 202–10. http://dx.doi.org/10.1590/0102-778631220150028.
Texto completoResumen
Abstract An integral semi-analytical solution of the atmospheric diffusion equation considering wind speed as a function of both downwind distance from a pollution source and vertical height is presented. The model accounts for transformation and removal mechanisms via both chemical reaction and dry deposition processes. A hypothetical dispersion of contaminants emitted from an urban pollution source in the presence of mesoscale winds in an unstable atmospheric boundary layer is showed. The results demonstrate that the mesoscale winds generated by urban heat islands advect contaminants upward, which increases the intensity of air pollution in urban areas.
5
Giyasov, Adham I. y Timur B. Giyasov. "The importance of local winds for the aerationof urban areas having hot and windless climatic conditions". Vestnik MGSU, n.º 10 (octubre de 2020): 1363–71. http://dx.doi.org/10.22227/1997-0935.2020.10.1363-1371.
Texto completoResumen
Introduction. A city with its high-rise buildings, greenery and landscaping that prevent air motion aggravate windless conditions typical for climates in the cities located in the southern latitudes characterized by heat and lack of wind. Urban built-up areas have stagnant and overheated air that causes sultriness and significant air pollutions caused by anthropogenic sources. These factors require systematization of the local aerodynamics by means of local wind generation using solar energy.
Materials and methods. Methods of theoretical research, large-scale field measurements involving the use of instruments, visual observations by means of smoke screening of the urban area’s structure were applied and laboratory research into thermal and wind processes using physical models of cities were applied to identify the role of insolation in the generation of local thermal winds that improve the local environment on the micro- and macroscale.
Results. The author has found that if built-up urban areas have no general circulation wind fields, urban aeration systems develop local independent air flows due to the temperature difference between heat and cool islands. The temperature difference was applied as the source material for an urban wind model and it also helped to identify the dependence of the local wind velocity on the thermal contrast of urban islands. A classification of aeration models is developed at macro; meso-; micro- and nanoscales.
Conclusions. The practical area of application of the theory of hot and windless processes was identified in respect of urban area planning. The aerodynamics of an urban environment was systematized due to the generation of local thermal winds. The process of local thermal wind generation was studied; the classification of natural aeration models was made for urban areas. Methods of using solar energy were applied to generate local winds, to develop the microclimate and to enhance the environment of urban areas and structures as a prerequisite for targeted urban planning actions, three-dimensional space-planning solutions that apply to urban structures, landscaping, architectural and structural concepts of buildings.
Acknowledgments. The work was performed in accordance with the research schedule of Department of Design of Buildings and Structures, NRU MGSU, focused on “Function, Structure, Environment in the Architecture of Buildings and Towns”.
6
Montero, Angel, M. Elias Dueker y Gregory D. O’Mullan. "Culturable bioaerosols along an urban waterfront are primarily associated with coarse particles". PeerJ 4 (22 de diciembre de 2016): e2827. http://dx.doi.org/10.7717/peerj.2827.
Texto completoResumen
The source, characteristics and transport of viable microbial aerosols in urban centers are topics of significant environmental and public health concern. Recent studies have identified adjacent waterways, and especially polluted waterways, as an important source of microbial aerosols to urban air. The size of these aerosols influences how far they travel, their resistance to environmental stress, and their inhalation potential. In this study, we utilize a cascade impactor and aerosol particle monitor to characterize the size distribution of particles and culturable bacterial and fungal aerosols along the waterfront of a New York City embayment. We seek to address the potential contribution of bacterial aerosols from local sources and to determine how their number, size distribution, and taxonomic identity are affected by wind speed and wind direction (onshore vs. offshore). Total culturable microbial counts were higher under offshore winds (average of 778 CFU/m3± 67), with bacteria comprising the majority of colonies (58.5%), as compared to onshore winds (580 CFU/m3± 110) where fungi were dominant (87.7%). The majority of cultured bacteria and fungi sampled during both offshore winds (88%) and onshore winds (72%) were associated with coarse aerosols (>2.1 µm), indicative of production from local sources. There was a significant correlation (p < 0.05) of wind speed with both total and coarse culturable microbial aerosol concentrations. Taxonomic analysis, based on DNA sequencing, showed that Actinobacteria was the dominant phylum among aerosol isolates. In particular,StreptomycesandBacillus, both spore forming genera that are often soil-associated, were abundant under both offshore and onshore wind conditions. Comparisons of bacterial communities present in the bioaerosol sequence libraries revealed that particle size played an important role in microbial aerosol taxonomy. Onshore and offshore coarse libraries were found to be most similar. This study demonstrates that the majority of culturable bacterial aerosols along a New York City waterfront were associated with coarse aerosol particles, highlighting the importance of local sources, and that the taxonomy of culturable aerosol bacteria differed by size fraction and wind direction.
7
Celada-Murillo, Ana-Teresa, Susana Carreón-Sierra, Alejandro Salcido, Telma Castro, Oscar Peralta y Teodoro Georgiadis. "Main Characteristics of Mexico City Local Wind Events during the MILAGRO 2006 Campaign within a Meso-β Scale Lattice Wind Modeling Approach". ISRN Meteorology 2013 (4 de febrero de 2013): 1–14. http://dx.doi.org/10.1155/2013/605210.
Texto completoResumen
A characterization of local wind events in Mexico City, which occurred during MILAGRO campaign, was carried out within the framework of a lattice wind modeling approach at a meso-β scale. Mexico City was modeled as a 2D lattice domain with a given number of identical cells. Local wind conditions at any cell were described by a state variable defined by the spatial averages of wind attributes such as speed, direction, divergence, and vorticity. Full and partial densities of wind states were discussed under different conditions using two simple lattice wind models. We focus on the results obtained with the 1-cell lattice wind model and provide brief comments about preliminary results obtained with the 4-cell model. The 1-cell model allowed identifying the main patterns of the wind circulation in Mexico City throughout the study period (anabatic and katabatic winds, winds induced by the urban heat island, and winds with high possibilities for exchanging pollutants between Mexico City and the neighboring settlements, among others). The model showed that Mexico City wind divergence and vorticity disclose superposed oscillations whose most important periods were 24 and 12 hours, suggesting strong connections with the diurnal cycle of incoming solar radiation and the urban heat island.
8
RAJ, P. ERNEST, P. C. S. DEVARA, R. S. MAHESKUMAR, G. PANDITHURAI y K. K. DANI. "Lidar-derived aerosol concentration and their relationship with horizontal winds over an urban location". MAUSAM 53, n.º 2 (18 de enero de 2022): 145–52. http://dx.doi.org/10.54302/mausam.v53i2.1630.
Texto completoResumen
Lidar-derived aerosol vertical profiles obtained at Pune, a low latitude tropical station, on about 535 days during a ten-year period (1987 – 96) along with simultaneous pilot-balloon wind (speed and direction) data of India Meteorological Department, Pune have been used in the study to investigate the influence of horizontal winds on the aerosol characteristics in the lower atmosphere. Aerosol column content in the atmospheric boundary layer (surface to 1100 m altitude above ground-level) as well as aerosol number density at the surface level (at 50 m) showed relatively higher values over the lidar site whenever the winds were blowing from the main urban and industrial regions of the city of Pune. This effect was found to be more pronounced during the winter season. Wind speeds also correlate well with increased aerosol loading, but only during selected high wind speed episodes. Thus the study shows that the short- and long-term increases in aerosol concentration/loading over the observation site are, to a large extent, influenced by horizontal winds in the surface layers and this in turn, can be attributed to the increasing human/urban activity around the lidar site over the years.
9
Li, Gang, Juan Cui, Tingshan Liu, Yongqiu Zheng, Congcong Hao, Xiaojian Hao y Chenyang Xue. "Triboelectric-Electromagnetic Hybrid Wind-Energy Harvester with a Low Startup Wind Speed in Urban Self-Powered Sensing". Micromachines 14, n.º 2 (23 de enero de 2023): 298. http://dx.doi.org/10.3390/mi14020298.
Texto completoResumen
Wind energy as a renewable energy source is easily available and widely distributed in cities. However, current wind-energy harvesters are inadequate at capturing energy from low-speed winds in urban areas, thereby limiting their application in distributed self-powered sensor networks. A triboelectric–electromagnetic hybrid harvester with a low startup wind speed (LSWS-TEH) is proposed that also provides output power within a wide range of wind speeds. An engineering-implementable propeller design method is developed to reduce the startup wind speed of the harvester. A mechanical analysis of the aerodynamics of the rotating propeller is performed, and optimal propeller parameter settings are found that greatly improved its aerodynamic torque. By combining the high-voltage output of the triboelectric nanogenerator under low-speed winds with the high-power output of the electromagnetic generator under high-speed winds, the harvester can maintain direct current output over a wide wind-speed range after rectification. Experiments show that the harvester activates at wind speeds as low as 1.2 m/s, powers a sensor with multiple integrated components in 1.7 m/s wind speeds, and drives a Bluetooth temperature and humidity sensor in 2.7 m/s wind speeds. The proposed small, effective, inexpensive hybrid energy harvester provides a promising way for self-powered requirements in smart city settings.
10
Moroni, Monica y Antonio Cenedese. "Laboratory Simulations of Local Winds in the Atmospheric Boundary Layer via Image Analysis". Advances in Meteorology 2015 (2015): 1–34. http://dx.doi.org/10.1155/2015/618903.
Texto completoResumen
In the atmospheric boundary layer, under high pressure conditions and negligible geostrophic winds, problems associated with pollution are the most critical. In this situation local winds play a major role in the evaluation of the atmospheric dynamics at small scales and in dispersion processes. These winds originate as a result of nonuniform heating of the soil, either when it is homogeneous or in discontinuous terrain in the presence of sea and/or slopes. Depending on the source of the thermal gradient, local winds are classified into convective boundary layer, sea and land breezes, urban heat islands, and slope currents. Local winds have been analyzed by (i) simple analytical models; (ii) numerical models; (iii) field measurements; (iv) laboratory measurements through which it is impossible to completely create the necessary similarities, but the parameters that determine the phenomenon can be controlled and each single wind can be separately analyzed. The present paper presents a summary of laboratory simulations of local winds neglecting synoptic winds and the effects of Coriolis force. Image analysis techniques appear suitable to fully describe both the individual phenomenon and the superposition of more than one local wind. Results do agree with other laboratory studies and numerical experiments.
Tesis sobre el tema "Urban winds"
1
Xia, Jiyang. "Numerical study on wind field and air pollutant dispersion in urban street canopies". Hong Kong : University of Hong Kong, 2000. http://sunzi.lib.hku.hk/hkuto/record.jsp?B22752857.
Texto completo
2
Zarovy, Samuel R. "Improved gust rejection for a micro coaxial helicopter in urban environments". Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/52992.
Texto completoResumen
Due to their small size, relative covertness, and high maneuverability, micro rotorcraft are ideal for a plethora of civilian and military applications in an urban environment such as, surveillance, monitoring, mapping, and search and rescue. It is envisioned that these vehicles will operate indoors confined complex spaces, and outside near the ground—among buildings and other obstacles. The aerodynamic velocity fields in these areas are notoriously complex with the mean winds varying spatially and temporally with sharp changes in wind magnitude and direction over small distances. This results in velocity perturbations which are on the same order of magnitude as the maximum flight speeds of micro rotorcraft leading to stall, large attitude perturbations, and loss of control; thus preventing micro rotorcraft from carrying out even the most basic missions.
This dissertation starts to fill the void in the literature on this topic by assessing how to design a micro coaxial helicopter with improved gust response in complex urban environments. Both experimental flight tests and modeling and simulation tools are developed and executed to analytically understand the challenges and potential solutions to enable rotorcraft to operate efficiently and robustly in urban environments. A set of performance metrics were developed to provide a framework to assess mission-level performance of micro rotorcraft in both flight experiments and simulation trade studies. A high fidelity dynamic model of a coaxial helicopter was developed to accurately simulate vehicle response to urban wind disturbances. The model was validated using flight experiments in a motion capture facility. Additionally, a dynamic inversion based Gust Rejection Control architecture was developed for the dynamic simulation which included a novel wind estimation algorithm that was utilized to improve controller performance and create a flight envelope protection scheme. The high fidelity dynamic model was employed to perform a variety of trade studies to: analyze vehicle response to prototypical urban wind kernels, understand the affect of wind estimation on the control architecture, assess the level of model fidelity required to adequately simulate vehicle response to urban winds, and identify key platform design parameter trends to improve wind disturbance capabilities. Overall the results show the challenges micro rotorcraft face in urban environments while highlighting some trends that can be helpful for future design and analysis efforts.
3
Mendes, Flávio Henrique. "Vulnerabilidade à queda de árvores por meio de simulações microclimáticas". Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11150/tde-22062016-165232/.
Texto completoResumen
Muitos são os benefícios provenientes da arborização de vias públicas, como aumento da vida útil do asfalto por meio do sombreamento, filtragem de poluentes, absorção de CO2, interceptação da água da chuva e da radiação solar e mitigação de ilhas de calor; porém, por questões culturais, é considerada muitas vezes pela população como algo negativo, cujas folhas entopem calhas, raízes destroem calçadas, troncos e folhas atrapalham fiação elétrica e, principalmente, elas estão susceptíveis às quedas. A pesquisa teve como objetivo estudar o comportamento das quedas de árvores no município de Piracicaba/SP, Brasil, com atenção especial ao regime de ventos na cidade, baseado em dados fornecidos pelo Corpo de Bombeiros de Piracicaba, Secretaria de Defesa do Meio Ambiente de Piracicaba (SEDEMA) e Estação Meteorológica da Escola Superior de Agricultura \"Luiz de Queiroz\" (ESALQ). De caráter inédito, o principal resultado foi a relação direta entre quedas e zonas urbanizadas, que, em constantes alterações no uso do solo, acabam por danificar a sustentação das árvores (raízes), fato justificado pela alta concentração de quedas na parte central (36,7%), com destaque para as estações da primavera e do verão, ou seja, ventos e chuvas, na qual, juntas, somaram 78,0% do total. O período de retorno esperado para ventos superiores a 75 km h-1, classificados como temporais na Escala de Vento de Beaufort, foi de 2,8 eventos por ano. Enquanto verificou-se o predomínio de ventos alísios de sudeste, pertencentes ao quarto quadrante, a direção das rajadas de vento teve maior variação e, assim, com predomínio daqueles ventos, é recomendável instalações de parques industriais nas zonas norte, noroeste e oeste, haja vista a importância de evitar que os poluentes adentrem a cidade. As espécies de maior vulnerabilidade foram: Pachira aquatica Aubl. (monguba), Handroanthus sp. (ipê roxo) e Tipuana tipu (Benth.) Kuntze (tipuana). Por meio de simulação microclimática computacional, utilizando o programa ENVI-met versão 3.1, em dois estudos de caso, sendo um em bairro residencial e outro na Praça José Bonifácio, foi possível identificar locais de maior atenção quanto às quedas de árvores, em função da rugosidade do local, capaz de alterar a velocidade e a direção do vento.There are many benefits from public roads afforestation, such as longer pavement life through shading, filtering pollutants, CO2 absorption, intercepting rainfall and solar radiation and mitigating heat islands; however, due cultural issues, is often regarded by the population as something negative, whose leaves clog gutters, roots destroy sidewalks, stems and leaves disrupt electrical wiring and, mainly, they are susceptible to falls. The research aimed to study the behavior of falling trees in Piracicaba/SP, Brazil, with special attention to the wind regime in the city, based on data provided by the Piracicaba Fire Department, Secretariat of Defense of the Environment of Piracicaba (SEDEMA) and Meteorological Station Luiz de Queiroz College of Agriculture (ESALQ). From unedited character, the main result was the direct relationship between falls and urbanized areas, which, in constant changes in land use, end up damaging the support of trees (roots), a fact explained by the high concentration of falls in the central part (36.7%), highlighted to the spring and summer seasons, i.e., winds and rains, which, together, totaling 78.0% of the total cases. The payback period expected to winds who exceeding 75 km h-1, classified as storms in the Beaufort Wind Scale, was 2.8 events per year. While there was a predominance of trade winds from the Southeast, belonging to the fourth quadrant, the direction of the gusts of wind had greater variation and, thus, with those predominant winds, it recommend installation of industrial parks in North, Northwest and West areas, since the importance of avoiding that pollutants enter into the city. The most vulnerable species were: Pachira aquatica Aubl. (Guiana Chestnut), Handroanthus sp. (Purple Ipe) and Tipuana tipu (Benth.) Kuntze (Tipuana). Through computational microclimate simulation, using the software ENVI-met version 3.1, in two case studies, being one in a residential area and another in the José Bonifácio Square, it was possible to identify locals of more attention as the falling trees, based on the local roughness, able to change the speed and direction of the wind.
4
Melo, Beatriz Cristina Barbalho de. "Estudo do campo térmico: o caso do Campus IV - UFPB". Universidade Federal da Paraíba, 2015. http://tede.biblioteca.ufpb.br:8080/handle/tede/8993.
Texto completoResumen
Submitted by Maike Costa (maiksebas@gmail.com) on 2017-06-09T13:53:11Z
No. of bitstreams: 1
arquivototal.pdf: 6611581 bytes, checksum: c211426580c5968c831b220686a8f8f8 (MD5)Made available in DSpace on 2017-06-09T13:53:11Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 6611581 bytes, checksum: c211426580c5968c831b220686a8f8f8 (MD5) Previous issue date: 2015-09-30
The microclimate consequences of a particular place to demonstrate that he as urban growth and exploitation of natural resources are increasing unfortunately. The weather is the most important component in maintaining the ecological balance. And his study becomes complex due to the various facets that involve him, turning indispensable interdisciplinary study, it could help in the reduction and / or more efficient solution of the urban problems. Studies of this order become relevant to planning and environmental management, which arouses interest for research on the thermal field of urban areas. The problem of this research is related to concern about anthropogenic implications on the local microclimate. It is known that human actions on the microclimate and the lack of proper planning of a particular place, can contribute to the thermal discomfort of users and demand higher energy costs. The present search, has as main objective to analyze the field thermal the Campus IVUFPB, located in the city of Rio Tinto-PB. In this case, seeks if relate the anthropogenic actions with the main thermal problems, detected on site. To obtain microclimate data, were installed in similar (which takes into account the type of soil cover, in this case, coating in cementitious composition) points, measuring equipment, in six points within the campus IV- UFPB, in dry season (from March 04 to April 7, 2015) and during the rainy season (from 09 June to 13 July 2015), totalizing 35 days in each measurement period. From the analysis and management of the data obtained, the presence of heat islands was detected within the study area as well as the rise in temperature in places with low circulation of winds and decreased moisture and the low individuals presence of arboreal. The results allowed the elaboration of suggestions with proposed thermal environmental, as; the ceramic roof replacement, in the hottest areas for green cover; replacing paving stones and interlocked block, per tread grass, that provide the minimization of thermal effects identified in the Campus IV-UFPB. With this, this research, can to corroborate to reveal the adverse effects of the anthropogenic actions that provoke microclimatic modifications in the thermal field of Campus IV-UFPB, making a relation with its urban components.
As consequências microclimáticas de um determinado local demonstram o quão desastrosamente o crescimento urbano e a exploração dos recursos naturais vêm aumentando. O clima é o componente mais importante na manutenção do equilíbrio ecológico. E seu estudo se torna complexo devido às diversas facetas que o envolvem, tornando imprescindível o estudo interdisciplinar que pode auxiliar, na diminuição e/ou solução mais eficiente das problemáticas do meio urbano. Estudos dessa ordem se tornam relevantes para o ordenamento e a gestão ambiental, o que desperta interesse para pesquisas sobre o campo térmico de áreas urbanas. A problemática desta pesquisa está relacionada com a preocupação sobre as implicações antrópicas sobre o microclima local. Sabe-se que as ações antrópicas sobre o microclima e a falta de planejamento adequado de um determinado local, podem contribuir para o desconforto térmico dos usuários e demandar maiores custos energéticos. A presente pesquisa tem como objetivo geral analisar o campo térmico do Campus IV-UFPB, localizado na cidade de Rio Tinto-PB. Nesse caso procura-se relacionar as ações antropogênicas com as principais problemáticas térmicas, detectadas no local. Para a obtenção de dados microclimáticos, foram instalados, em pontos semelhantes (que levam em consideração o tipo de recobrimento do solo, neste caso, revestimento de composição cimentícia), equipamentos de medição, em seis pontos dentro do campus IV-UFPB, no período seco (de 04 de Março a 07 de Abril de 2015) e no período chuvoso (de 09 de Junho a 13 de Julho de 2015), somando-se 35 dias em cada período de medição. A partir da análise e ordenamento dos dados coletados, ficou constatada a presença de ilhas de calor dentro da área de estudo, bem como o aumento de temperatura em locais com pouca circulação dos ventos e a diminuição da umidade em locais com pouca presença de indivíduos arbóreos. A análise dos resultados permitiu elaborar sugestões com propostas termo ambientais do tipo, substituição de telhado cerâmico, nas áreas mais quentes, por telhado verde extensivo; a substituição de paralelepípedos e blocos intertravados, por piso grama que proporcionem a minimização dos efeitos térmicos identificados, no Campus IV-UFPB. Com isso, esta pesquisa, pode vir a corroborar no desvendar dos efeitos adversos das ações antropogênicas, que provocam alterações microclimáticas no campo térmico do Campus IV-UFPB, fazendo uma relação com seus componentes urbanos.
5
Dosset, Pablo. "Urban Wind Power : Installation of an Urban Wind Power turbine in Polhemsskolan in Gävle". Thesis, University of Gävle, Department of Technology and Built Environment, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-760.
Texto completoResumen
Urban wind power is not too developed yet. Only some years ago some countries started to be aware of the important source of energy that can be used within built-up areas. The U.K., the Netherland, France and Italy are already working on it, but they are still far away to reach models and equations that can be useful for any situation.
An urban turbine is going to be installed in Gävle, Sweden, in the roof of Polhemsskolan. Therefore, the wind velocity should be found out to come up with some results about the energy yield. But some problems appear when try to estimate that velocity.
To calculate this velocity three different ways can be used. They are Mathematical models, Measurements and Simulations or Computational Fluid Dynamic (CFD) calculations. All of them are quite difficult to use. Both mathematical models and CFD are very expensive as well as they need too much time to give a result. In addition, the area where the rotor is going to be installed is quite strange and therefore, it is even more difficult to put all the data in the mathematical model or CFD. On the other hand, measurements were almost impossible to carry on. The measurement of the wind velocity should be done during one year due to the big differences in that value depending on the season; winter, summer... depending on the weather; cloudy, sunny and so on. This thesis was only four months long and that was not enough to do it. It has been tried too to use any measurements that could be in any weather stations in the surrounding of Gävle. Nothing was found. No wind velocity measurements have been made in this area.
Hence, different books and reports about this topic have been study quite depth. Most of them from the U.K. Estimations and assumptions were taking into account to come up with different solutions to make easier in the future to calculate an energy yield when measurements will be done.
6
Bottema, Marcel. "Wind climate and urban geometry /". Online version, 1993. http://bibpurl.oclc.org/web/24411.
Texto completo
7
Drew, Daniel. "Analysis tools for urban wind turbines". Thesis, University of Reading, 2011. http://centaur.reading.ac.uk/35837/.
Texto completoResumen
With the UK seeking to increase the contribution of microgeneration, the number of small wind turbines installed in urban areas has increased. However, a wide-spread experience is that urban located turbines have generated considerably less energy than anticipated. This thesis demonstrates that poor turbine placement, due to inadequacies in commonly used wind resource modelling and assessment techniques, has played a large part in this disappointing outcome. The current site assessment tools estimate a turbine's performance at a potential site using a method developed for large scale wind energy projects in rural areas. Using data measured at 91 Met Office weather stations across the UK and a rooftop site in London, this thesis shows that when applied in urban areas, this method can lead to large errors in the predicted energy production of a small wind turbine. The magnitude of these errors is such that the tools cannot consistently identify the economic viability of a turbine/site combination. This is largely due to a simplified representation of the site's wind resource. By not considering the decelaration of the wind by friction, there are large errors in the predictions of a site's annual mean wind speed. Across the sites there is a mean error of over 40% and 18% for the DECC wind speed database and the Carbon Trust tool respectively. Furthermore, analysis of data collected at the roof top site shows that due to high levels of turbulence in urban areas, a Weibull distribution does not provide a sufficient representation of the temporal variability of a site's wind resource. 1 Subsequently the thesis develops an improved, more reliable means of predicting mean wind speed at urban sites by considering interactions between the flow and the morphology of built-up areas in more detail than has been possible previously. When applied to the Greater London area the model shows that turbines generally perform better towards the outskirts of the city, however there are some sites with good wind resource close to the city centre with low aerodynamic roughness.
8
Claus, Jean M. "Wind direction effects on urban flows". Thesis, University of Southampton, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.560582.
Texto completoResumen
In the research on urban flows, two trends can be distinguished: some studies based on real urban environments, either in the field or on reproductions; and some on simplified models. One such model, a staggered cube array, has been investigated extensively, both experimentally in wind tunnels and numerically using LES and DNS, but always with a flow direction normal to the faces of the cubes. We are here investigating the effects of different wind directions on the flow within and above the cube array. As no other study has been published on the subject, both numerical and experimental investigation methods have been used. For the numerical side, large-eddy simulations were conducted using the finite volume method implemented in commercial software (StarCD, CD-adapco). The half-channel flow simulated was driven by a momentum source equiva- lent to a pressure gradient. The results are shown to agree well with those of wind-tunnel experiments conducted in parallel. For the experimental side, the boundary layer flow is measured in two dimensions using particle-image velocimetry and the drag using pressure tapped cubes and a drag balance. The results show that the mean flow field within the canopy is only weakly dependent on the direction of the flow above. Above the canopy, the mean velocity profile, time av- eraged and spatially averaged in horizontal layers, is shown to include an inertial sublayer where a logarithmic profile can be fitted. The fit proves to be best by considering for zero-plane displacement the height at which the mean drag acts and points arguably in the direction of a flow dependent value of the Von Karman constant. At the top of the numerical domain, the mean flow is also deviated from the direction of the forcing. We show that this deviation is directly related to previously unseen lift forces applied on the cubes. On balancing the different forces in the numerical domain, the viscous contribu- tions to both the lift and the drag forces are shown to be larger than anticipated from previous studies. Although these results could not be validated by the experiments as the viscous forces remain small compared to the experimental errors, such contributions raise concerns with regards to the Reynolds number independence of the flow and to the need for more complex wall conditions for LES. Overall, the variations of the flow pa- rameters are not negligible and prove to be non-linear and non-monotonic with the flow angle which highlights the importance of considering the flow direction when studying or parameterising urban landscapes. 1.
9
Dymock, Ben R. "Urban wind turbines : a feasibility study". Thesis, London South Bank University, 2017. http://researchopen.lsbu.ac.uk/1864/.
Texto completoResumen
There is an existing body of research into noise, vibration and wind regime concerns associated with urban wind turbines demonstrating the detrimental effects of these topics on the energy yield potential and therefore financial worth of an installation. Much of the research has focused on wind regime assessment and optimum roof top placement via CFD modeling offering generalised guidelines showing a potential for wind power to contribute towards lowering London's CO2 emissions. Unfortunately, without benefiting from appropriate planning assessment, a number of early urban turbines failed and have risked irreversibly tarnishing the concept. Hitherto no studies have been specifically conducted on the urban potential of building integrated wind turbines. As integration is bespoke, typically determined by the architecture, it is unknown whether existing guidelines for roof mounted wind turbines could be directly applied. It is probable that each installation would merit its own assessment and analysis procedure. This study aims to investigate the differences between roof mounted and building integrated turbines in terms of assessment, operation and urban potential. In response to these differences it is intended to demonstrate how a successful installation can be achieved. Comparisons between two urban sites, one smaller, roof mounted HAWT and one larger, building integrated HAWT have been made via noise, vibration, CFD and atmospheric data recorded and analysed over two years to build a comprehensive understanding of the inherent urban issues. The prospect of successfully situating an urban turbine is complex in nature and considering the high installation costs and high level of design and engineering required to do so it is imperative that their energy yield provide a satisfactory return on investment and efficient supply of power without adversely impacting upon the surrounding environment or themselves. This study concludes that a multifaceted approach is necessary to achieve an efficient building integrated turbine, comprised of: (i) accurate local noise surveys to establish the local acoustic environment to inform acceptable turbine operating ranges, (ii) specific noise modeling of manufacturer provided data or, where none is available, acoustic testing of the proposed turbine across all applicable wind speed ranges, (iii) comprehensive vibration assessment, not only of the turbine tower/system but also of the turbine housing and any lower residential floors to ensure no natural frequencies will be excited and to prevent any vibration transmission via appropriate mounting, isolation or damping where necessary, (iv) the acquirement of site specific wind data to inform architectural design, turbine selection and placement. If monitoring at hub height is not possible it has been found that it may be acceptable to monitor in close proximity and then extrapolate the results using CFD analysis and wind profile methods, (v) CFD modeling of the surrounding topography, the turbine mount and/or enclosure. These areas are discussed with potential areas of noise and vibration control and turbine optimisation, specific to the case studies, investigated. Further to the aforementioned study an investigation into a new method of assessing noise and vibration levels associated with average anemometry recorded wind speeds has been presented so as to attain average levels per wind speed bin without being skewed by impulsive gusts.
10
Peregrino, Paulo Sérgio Araújo. "A influência do padrão de adensamento nas características de um escoamento urbano : uma aplicação à região do Altiplano Cabo Branco em João Pessoa-PB". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2014. http://hdl.handle.net/10183/180629.
Texto completoResumen
Faz-se notória a ideia de que o crescimento das cidades e o consequente aumento no adensamento das mesmas é, nos dias atuais, um fato inevitável; e que o homem, ao modificar o meio natural, o faz quase sempre de forma danosa. Formação de ilhas de calor, aumento do consumo de energia, dificuldade na dispersão de poluentes, diminuição do ângulo de visão do céu, diminuição da taxa de permeabilidade do solo entre outros, são problemas frequentemente relacionados com a densificação e verticalização das cidades. A utilização de modelos reduzidos para simulações experimentais em túneis de vento das condições naturais de ventilação se mostram eficazes, além de reduzir custos em pesquisas nesta área. Embasando-se em tais pressupostos, o presente trabalho pretende verificar as alterações das características dos escoamentos de vento provocadas por distintos padrões de ocupação do solo urbano no bairro do Altiplano Cabo Branco, na cidade de João Pessoa-PB. A área em estudo atravessa um processo acelerado de modificação nas suas características de ocupação urbana, conduzido pelas alterações dos indicadores urbanísticos locais, antes mais restritivos, possibilitando agora edificações com gabaritos em altura significativamente maiores do que os anteriormente observados no local. Parte-se então da hipótese de que o processo de verticalização resultante deste crescimento é capaz de alterar os escoamentos de ventos não apenas nas áreas onde este ocorre, mas também em áreas contíguas. No desenvolvimento deste trabalho, de caráter experimental, foram avaliados dois modelos de adensamentos urbanos para a área de estudo O primeiro deles reproduz a ocupação da área conforme se encontrava antes de mudanças ocorridas nos indicadores urbanísticos para o local. O segundo apresenta a configuração atual de ocupação da área, delineada pela legislação em vigor. Para viabilizar esta avaliação serão realizados ensaios no Túnel de Vento de retorno fechado, Professor Joaquim Blessmann, do Laboratório de Aerodinâmica das Construções da Universidade Federal do Rio Grande do Sul, utilizando maquetes (modelos) em escala reduzida e observando os requerimentos necessários estabelecidos para este padrão de estudo experimental. Foram utilizados nos ensaios para cada uma das duas configurações de vizinhança dois ângulos de ataque de vento, 150 e 90 graus, tomando como referência o atlas de vento do local de estudo. A partir da análise dos resultados obtidos é possível concluir que a verticalização, da maneira como propõe legislação atual para a área, não apresenta perdas significativas no que se refere aos escoamentos (ventos) quando comparada com o padrão de ocupação anterior sem os edifícios altos. As áreas adjacentes também não sofrem maiores prejuízos no que se refere aos escoamentos quando comparados os dois modelos.What is worth elucidating is the idea about city expansion and consequent increasing effects of the densification is, now are days, an unavoidable fact; and that human, by modifying the natural environment, does so always in a destructive way. Formation of heat island, increase of the energy consumption, difficulty in the dispersion of pollutants, reduction in the sky view angle, diminution of the level of soil permeability among others, are problem frequently related to densification and verticalization of cities. The use of reduced models for experimental simulation in wind tunnel considering natural conditions of ventilation prove to be effective, apart from low down cost of experiments in this area of research. Based on such assumption, the aim of this research was to verify the alterations of wind flow characteristics provoked on distinct occupation pattern of urban soil in the district of Altiplano Cabo Branco, in the city of João Pesssoa-PB. The studied site passed through a fast process of physical modification in its urban occupation characteristics, conducted by local urban indicators, which was earlier more restrictive, presently permitting building with considerable standard that are higher than those, which were formerly observed on site. Based on the assumption that the process of verticalization as a product of growth may alter the wind flow not only in the areas where it occurs but also in adjacent areas In developing this work, experimentally, two models of urban concentrations were examined on the study area. The first was reproduced on the occupation of the area as it was founded before the changes in the local urban indicators. The second shows the current configuration of occupation of the area outlined by the current legislation. To make this assessment tests were carried out in the Boundary layer wind tunnel, Professor Joaquim Blessmann, of Federal University of Rio Grande do Sul, by use of model building of reduced scale and observing the necessary requirements established for this standard experimental study. Two angles of attack of wind were utilized in the two experiments, 150 and 90 degrees, with reference to the wind atlas of site of study. From the result of this analysis we conclude that virtualization of the occupation proposed by the current proposed legislation for the site does not present significant losses when compared with the previous standard of occupation lacking the tall buildings. Adjacent areas do not affected by losses in relation to the wind flow of the two models that was compared.
Libros sobre el tema "Urban winds"
1
Ernst, Sylke A. Tagesperiodische Windsysteme und Belüftungsverhältnisse in Freiburg i.Br.: Planungsrelevante Aspekte eines Bergwindsystems. [Freiburg i.Br.]: Im Selbstverlag des Institutes für Physische Geographie der Albert-Ludwigs-Universität Freiburg i.Br., 1995.
Buscar texto completo
2
Clawson, K. L. Meteorological measurements during the urban 2000/VTMX field study. Silver Spring, Md: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, Oceanic and Atmospheric Research Laboratories, Air Resources Laboratory, 2002.
Buscar texto completo
3
E, Cermak J. y NATO Advanced Study Institute on Wind Climate in Cities (1993 : Waldbronn, Germany), eds. Wind climate in cities. Dordrecht: Kluwer Academic Publishers, 1995.
Buscar texto completo
4
Center, Turner-Fairbank Highway Research, ed. Issues affecting dispersion near highways: Light winds, intra-urban dispersion, vehicle wakes, and the Roadway-2 Dispersion Model. McLean, VA (6300 Georgetown Pike, McLean, 22101-2296): U.S. Dept. of Transportation, Federal Highway Administration, Research, Development, and Technology, Turner-Fairbank Highway Research Center, 2001.
Buscar texto completo
5
Schuhmacher, Peter. Messung und numerische Modellierung des Windfeldes über einer Stadt in komplexer Topographie. Zürich: Verlag der Fachvereine Zürich, 1992.
Buscar texto completo
6
Giosa, Pierpaolo. World Heritage and Urban Politics in Melaka, Malaysia. NL Amsterdam: Amsterdam University Press, 2021. http://dx.doi.org/10.5117/9789463725026.
Texto completoResumen
Already celebrated as a busy entrepôt and the most glorious of the Malay kingdoms of the past, Melaka has been on the UNESCO World Heritage List (together with George Town) since 2008 on the strength of its multi-ethnic and multi-religious urban fabric. Yet, contrary to the expectations of heritage experts and aficionados, the global mission of safeguarding cultural heritages has become a tumultuous issue on the ground. In World Heritage and Urban Politics in Melaka, Malaysia: A Cityscape below the Winds how the World Heritage 'label' has been, and continue to be used by different actors – such as international organizations, nation states, and society at large – to generate new economic revenues as well as to attract tourists and investments for large-scale real estate development projects is analyzed, revealing the complex and often contradictory stories behind heritage designations in urban milieus.
7
Center, Turner-Fairbank Highway Research, ed. Issues affecting dispersion near highways: Light winds, intra-urban dispersion, vehicle wakes, and the Roadway-2 Dispersion Model. McLean, VA (6300 Georgetown Pike, McLean, 22101-2296): U.S. Dept. of Transportation, Federal Highway Administration, Research, Development, and Technology, Turner-Fairbank Highway Research Center, 2001.
Buscar texto completo
8
Yuan, Chao. Urban Wind Environment. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-10-5451-8.
Texto completo
9
Neil, Campbell y Harries Alan, eds. Urban wind energy. Sterling, VA: Earthscan, 2009.
Buscar texto completo
10
Boston Natural Areas Fund. 1990 Boston urban wilds report. Boston: The Fund, 1991.
Buscar texto completoCapítulos de libros sobre el tema "Urban winds"
1
Hatchett, Benjamin J., Michael L. Kaplan, Nicholas J. Nauslar, Craig M. Smith y Kellen Nelson. "Slope Winds". En Encyclopedia of Wildfires and Wildland-Urban Interface (WUI) Fires, 1–9. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-319-51727-8_209-1.
Texto completo
2
Sharples, Jason J. "Foehn Winds". En Encyclopedia of Wildfires and Wildland-Urban Interface (WUI) Fires, 1–7. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-51727-8_71-1.
Texto completo
3
Hatchett, Benjamin J., Michael L. Kaplan, Nicholas J. Nauslar, Craig M. Smith y Kellen Nelson. "Slope Winds". En Encyclopedia of Wildfires and Wildland-Urban Interface (WUI) Fires, 922–30. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-319-52090-2_209.
Texto completo
4
Sharples, Jason J. "Foehn Winds". En Encyclopedia of Wildfires and Wildland-Urban Interface (WUI) Fires, 490–96. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-319-52090-2_71.
Texto completo
5
Ridwansyah, Muhammad, Christopher Bennett, Franky M. S. Telupere, Philiphi de Rozari, Fadwa R. Asfahani, Utari N. Qalbi y Achmad F. Kanzil. "Strategy for Sustainable Urban Climate Mitigation: Kupang City Climate Risk Assessment". En Environment & Policy, 405–14. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-15904-6_21.
Texto completoResumen
AbstractKupang City is one of the cities in Indonesia that is vulnerable to disasters caused by climate change, mainly prolonged dry season, strong winds, and increasing GHG emissions. These disasters will significantly affect all aspects of life, such as ecosystems, property, and infrastructure. This vulnerability is worsened by increasing urbanization, which creates additional risks for many people. This also can be explained by the growing number of motorized vehicles, which caused an increase in NO2 (Nitrogen Dioxide). Data shows that a higher concentration of NO2 was found on roadsides, amounting to 22,16 μg/m3. Therefore, in this study, the geographical, demographic, and socioeconomic characteristics of Kupang City were analyzed to find the shortcomings and the challenges faced by Kupang City in order to implement policies related to climate risk reduction. This study aims to investigate the status of the current phenomenon by using descriptive design. Based on the literature analysis, it was found seven priority sectors, which considered able to resolve the disasters and challenges caused by climate change. The seven sectors are climate change adaptation and disaster risk reduction, water and sanitation, energy and transportation, solid waste management/municipal waste, sustainable use of resources, GHG emission inventory, and financing.
6
Knoeff, Rina. "Breathscapes: Natural Environments in Eighteenth-Century Physiology and Psychosomatics of Breathing". En The Life of Breath in Literature, Culture and Medicine, 217–39. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-74443-4_11.
Texto completoResumen
AbstractThe eighteenth century was obsessed with the physiology and pathology of respiration and the necessity of clean air and strong winds for health and well-being. Air referred not only to the air we breathe, but also to the natural environments that produce (i.e., breathe) and determine the quality of air. Knoeff’s essay is concerned with the question of how the (psycho) pathology of respiration is bound up (conspires) with natural environments, not only in the literal sense (in urban spaces as well as the countryside) but also as represented in the material and visual culture of households, most notably in landscape paintings in living rooms. It was thought that the viewing of spacious landscapes would stimulate the imagination and literally give breathing space.
7
Plate, E. J. "Urban Climates and Urban Climate Modelling: An Introduction". En Wind Climate in Cities, 23–39. Dordrecht: Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-017-3686-2_2.
Texto completo
8
Hong, Dong-Li y Shiuh-Shen Chien. "‘Summoning’ Wind for Urban Cooling: Urban Wind Corridor Projects in China". En Designing Cooler Cities, 137–50. Singapore: Springer Singapore, 2017. http://dx.doi.org/10.1007/978-981-10-6638-2_10.
Texto completo
9
Schatzmann, Michael, Stylianos Rafailidis y Nijs Jan Duijm. "Wind Tunnel Experiments". En Urban Air Pollution — European Aspects, 261–76. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-015-9080-8_14.
Texto completo
10
Krupar III, Richard J. "Wind". En Encyclopedia of Wildfires and Wildland-Urban Interface (WUI) Fires, 1–4. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-319-51727-8_133-1.
Texto completoActas de conferencias sobre el tema "Urban winds"
1
Duggan, Christopher D. y Michiel J. G. Jak. "Wind Power for Urban Applications". En ASME 2004 Power Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/power2004-52041.
Texto completoResumen
Wind power offers the possibility of onsite generation of renewable energy for residential, commercial and industrial energy users in urban and suburban areas. This form of electricity production has generally been limited to rural and utility applications, but continued improvements have generated new interest in the potential of wind power in urban environments. There are several key elements that determine the viability of urban wind power, the most important of which are turbine technology, wind resources, costs and regulations. This paper will examine these elements with the goal of assessing the current status and future potential of urban wind power. Urban environments present a unique set of challenges to wind power, which demand turbine technology specific to these applications. Buildings create turbulent wind patterns, destroying the constant, steady winds on which utility scale turbines are dependant. Noise, shadow and vibration due to turbines is more important in urban applications, and turbine esthetics becomes a major focus. A new generation of wind turbines is now being produced with these concerns specifically in mind. There are a variety of solutions to these problems, which designers are beginning to explore. An essential element in the success of a turbine is the availability of wind resources. New turbine designs are being produced to utilize lower velocity winds. Additionally, engineers and architects can create better turbine locations through the integration of turbines with building design. Through this integrated design, buildings can contribute to the wind resources by increasing wind speeds and directing wind through the turbine. Available wind and turbulence, along with the characteristics of the particular turbine design, dictates how much electricity can be produced. The third critical aspect of urban wind power is the cost of producing electricity. To gain success, urban wind generators must be cost competitive with other urban applications of renewable energy technologies. The primary competition in this market is from solar photovoltaics, which currently produce power at about 50 ct/kWh. Utility scale wind turbines are not part of this market, and therefore do not compete with urban turbines. Urban turbines have the potential to produce electricity at costs of down to 10 ct/kWh. Future technology improvements, along with increased production, could significantly reduce the capital cost and further reduce the price of generating power. There are also opportunities for tax incentives, feed-in tariffs and other subsidies that can reduce the installed cost of wind power. Finally, regulations and policy can be a major obstacle to urban wind power. This includes zoning and building codes, as well as electronics certifications and interconnection regulations. This paper will examine existing and future turbine technologies, urban wind resource availability and the costs associated with producing energy via urban wind power. It will also identify roadblocks to the implementation and assess the overall viability of this type of renewable energy production.
2
Jiang, Xiaohai, Yiannis Andreopoulos, Zhexuan Wang, Joan Gomez y Oleg Goushcha. "Video: Flow patterns in urban neighborhoods under hurricane force winds". En 71th Annual Meeting of the APS Division of Fluid Dynamics. American Physical Society, 2018. http://dx.doi.org/10.1103/aps.dfd.2018.gfm.v0075.
Texto completo
3
Schajnoha, Sharon, Hali Barber, Guy Larose, Maryam Al-Labbad y Alanna Wall. "The Safety of Advanced Air Mobility and The Effects of Wind in the Urban Canyon". En Vertical Flight Society 78th Annual Forum & Technology Display. The Vertical Flight Society, 2022. http://dx.doi.org/10.4050/f-0078-2022-17611.
Texto completoResumen
The safe integration of vertical takeoff and landing aircraft (VTOLs) into an urban setting requires careful consideration of the effects of the wind flows through the urban canyon, which are complex and cannot be predicted with the reliability level necessary to enable safe operations. The assessment of wind in the urban canyon is critical to the siting and design of vertiports and safe operations of VTOLs. Vertiport design guidance related to the effects of wind flows in the urban canyon is limited and draws from helipad design guidance. The guidance recommends that wind conditions be assessed across a vertiport, but the guidance does not suggest how the study should be conducted nor does it provide design thresholds for wind. RWDI, the National Research Council Canada and Transport Canada have joined forces to identify and study the wind characteristics that would be important for the aerodynamic performance of VTOL and how these characteristics would be influenced by buildings and structures in the urban environment. In the framework of this research effort, an experimental approach was developed, centered on several sites in Canadian cities, representing a range of urban densities and surrounding topographies, as wind conditions are highly dependent on the built environment, including building footprint, building features, combinations of buildings and the local climatology. The work involved a quantitative approach in which physical models of several urban sites were built, instrumented and tested in boundary layer wind tunnels. In the wind tunnel experiments, "red flag" wind conditions were identified and measured. Detailed data capturing these flow features were collected around roof tops of lower and taller buildings, representing prospective vertiport locations and along prospective flight paths. This paper provides the details of the wind tunnel testing conducted for one of the urban sites; a site with an existing helipad at a hospital and a low-rise parking garage. The wind tunnel measurements were compared to published helipad design thresholds and combined with long term meteorological conditions representative of the site to determine how often vertiport operations will be limited by unfavourable urban wind conditions on an annual basis and by season. The wind tunnel study provides a case study and demonstrates how to evaluate the safety of a vertiport now, based on limited availability of VTOL aerodynamic performance capabilities and into the future as more information becomes available on VTOL performance in turbulent winds.
4
Li, Xiangyi, Marko Princevac y Ronald Calhoun. "Accuracy of a Coherent Doppler Lidar for the Urban Boundary Layer Measurements". En ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-80708.
Texto completoResumen
A large field experiment, dubbed Joint Urban 2003 (JU2003), took place in Oklahoma City in July 2003. The key component of this experiment was to study the movement of inert tracer gases through the urban environment. A large variety of atmospheric measurement systems have been deployed during the experiment - providing unprecedented opportunities to investigate questions related to the urban flows and dispersion. Two Doppler lidars were deployed with the main purpose to give a deeper insight to the coupling between the free-stream wind and urban centers. The Coherent Doppler lidar technology provides an effective way for remote measurements of the mean winds and turbulence, however, lidars are prone to the noise related measurement errors. Generally, the accuracy of the lidar measurements decreases with the increasing distance due to the weakening of the signal-to-noise ratio (SNR). The first step in the analysis was the calculation of power density spectra of the radial velocity for each range gate. During the experiment the sampling rates of 10 and 5 Hz corresponding to the Nyquist frequency of 5 and 2.5 Hz, respectively, were used. In order to alienate the effect of estimation errors due to the high frequency noise, the constant part of spectrum was examined. The estimate variance as well as standard deviation of estimation errors were determined from the integral of this constant spectrum. To give more accurate description of estimation errors for the cases far away from the lidar where the noise becomes significantly large, the data was filtered using sample averaging technique. This study emphasizes the situations when the lidar measurements should be taken with caution. The recommendations for noise reduction and filtering techniques are given.
5
Basso, Davide y Carlo Cravero. "A Numerical Simulation Approach for Atmospheric Pollution Evolution at Urban Scale to Help Traffic Control Decision Making". En ASME 2012 11th Biennial Conference on Engineering Systems Design and Analysis. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/esda2012-82028.
Texto completoResumen
For a town with complex orography and frequently varying winds, like Genova on the Italian Northern coast, the need for a simulation environment to predict the pollutant evolution according to a given traffic load, would be of utmost importance. A simulation approach based on 3D CFD has been developed keeping in mind the final application: it use for decision making. Several meshes have been set up and their effects on the solution evaluated in order to strike a balance between the quality of physical modelling and the computational resources required to handle it. The aim is that of getting useful results in a short timescale (one/two days). The evolution of the 3D flow and the pollutants has been simulated for two reference days with a time resolution of one hour. The effect of the daily evolution of the wind, heat release and pollution emission (traffic) over 24 hours is highlighted and discussed.
6
Neophytou, Marina K. A., Harindra J. S. Fernando, Ekaterina Batchvarova, Mats Sandberg, Jos Lelieveld y Eleonora Tryphonos. "A Scaling Law for the Urban Heat Island Phenomenon: Deductions From Field Measurements and Comparisons With Existing Results From Laboratory Experiments". En ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21819.
Texto completoResumen
We report results from a multi-scale field experiment conducted in Cyprus in July 2010 in order to investigate the Urban Heat Island (UHI) in Nicosia capital city and its interaction with multi-scale meteorological phenomena taking place in the broader region. Specifically, the results are analysed and interpreted in terms of a non-dimensional/scaling parameter dictating the urban heat island circulation reported from laboratory experiments (Fernando et al, 2010). We find that the field measurements obey the same scaling law during the day, in the absence of any other flow phenomena apart from the urban heating. During the night we find that the deduced non-dimensional value reduces to half (compared to that during the day); this is due to the presence of katabatic winds from Troodos mountains into the urban center of Nicosia and their cooling effect superimposed on diurnal urban heating. Based on this deduction, the impact of various proposed heat island mitigation measures in urban planning can be evaluated.
7
Besjak, Charles, Bonghwan Kim, Alexandra Thewis y Jing Zhuang. "35 Hudson Yards: Adapting to Urban Infrastructure with High Strength Concrete". En IABSE Congress, New York, New York 2019: The Evolving Metropolis. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2019. http://dx.doi.org/10.2749/newyork.2019.0095.
Texto completoResumen
<p>The urban context provides unique challenges and opportunities for engineering. In New York, large blocks of land previously dedicated to railyard functions are being reclaimed as new urban centers. 35 Hudson Yards is a 72-story mixed-use building located entirely over railroad tracks in midtown Manhattan. To construct the highest residential tower at Hudson Yards, innovative solutions using high strength concrete are required to manage load path and structural integrity challenges. The 308 meter (1,010 feet) high reinforced concrete structure coordinates core wall and column placement with the constraints imposed by the existing infrastructure below. “Tuning” of the concrete system adapt the tower structure to the capacities of the foundations and platform structure designed before the superstructure. Lower levels of the supertall also act as bridging elements, spanning across tracks to channel tower loads to limited lines of support. Despite its impressive height and the structural challenges of the site, 35 Hudson Yards is a robust, stiff structure, designed to resist strong winds from the Hudson River and constructed with an aggressive schedule, utilizing two day cycles for the residential levels. It is a quintessential New York achievement—a bold statement of architecture and engineering, overcoming constraints and maintaining non-stop operation of critical infrastructure.</p>
8
Ruiz de Villa, Arturo, Javier Oliva y Iñaki Auzmendi. "Design of structural systems for artworks fabrication and installation in urban areas". En IABSE Congress, New York, New York 2019: The Evolving Metropolis. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2019. http://dx.doi.org/10.2749/newyork.2019.2377.
Texto completoResumen
<p>In urban areas, besides structures such as bridges and buildings, big sculptures are each day more common as major pieces of public art. Although these artworks are not meant to satisfy needs as housing or transport, they play an important role in the city: they are major pieces of art made accessible to everyone that enhance the environment and contribute to the urban planning.</p><p>Major sculptures must withstand the same load types as the rest of the city’s infrastructure, for example strong winds and earthquakes. The analysis of these structures is an unorthodox field for civil engineers where new challenges appear: complex shapes, innovative materials, new fabrication techniques… Moreover, public art is a field that continually evolves. Art and engineering become two aspects of the same creative process and the interaction between professionals is fundamental.</p><p>In this work, several success cases in design, fabrication and installation of artworks by some international artists in inhabited areas all over the world are presented. We reflect on the limits in analysis and design focusing on the limitations imposed by the engineering codes. The search for compromise solutions that produce safe structures that still send the artist’s message is also discussed.</p>
9
Marini, Martino, Renato Gazzano y Antonio Satta. "Semi-Empirical Methods for the Analysis of Vertical Axis Wind Turbines With Helical Blades". En ASME Turbo Expo 2010: Power for Land, Sea, and Air. ASMEDC, 2010. http://dx.doi.org/10.1115/gt2010-23460.
Texto completoResumen
The Vertical Axis Wind Turbine (VAWT) was not successful for large size installations but it is suitable for small size applications. It is likely to integrate better in an urban environment due to its architectural features and its intrinsic capability to exploit winds from any direction without an orientation system. The performances of these machines can be evaluated with enough accuracy by means of the semi-empirical models that allow to explore various configurations in a straightforward way. They need the support of experimental investigations for aerodynamic coefficients and they have to refer to a limited class of airfoils. However they can be matched with CFD tools usefully to enlarge the field of investigation keeping the above advantages. In the paper the performance of the H type (giromill) configuration as well as of the helical rotors are calculated and compared. The latter geometry has received recently a special attention on account of some aspects that are discussed.
10
Niranjana, J. S., Feba Paul, Hridya D. Nambiar, Ashly Joy y Neethu Roy. "Flood Risk Assessment of Thiruvananthapuram City, Kerala". En International Web Conference in Civil Engineering for a Sustainable Planet. AIJR Publisher, 2021. http://dx.doi.org/10.21467/proceedings.112.21.
Texto completoResumen
Flood is one of the most dangerous and deadliest natural hazards in the world which devastates both life and economy to a very large extent. In Kerala, climate change induced floods are becoming an annual problem. In the midyear of 2018 and 2019, Thiruvananthapuram, the capital city of Kerala, witnessed heavy rainfall and strong winds which resulted in widespread damage in various parts of the City. Flood risk assessment study provides a comprehensive detail of geographic areas and elements that are vulnerable to the particular hazard. As far as Thiruvananthapuram is considered, most of the flood risk assessment studies available were found to be based only on a specific catchment or stream. This paper discusses the need of flood risk assessment study of Thiruvananthapuram City and also focuses on estimating the intensity of storm causing flood. In this work, the major natural drains and the places prone to drainage concentration are delineated from Digital Elevation Model of the study area. The drainage map and land use map are prepared using ArcGIS and ERDAS software respectively. The hydraulic modeling is done using HEC-RAS software and simulations for different rainfall intensities are carried out to estimate the magnitude of flood and to identify the major flood prone areas in the City. This study presents a systematic methodology that can be adopted for flood risk assessment of urban cities, especially when there is less available data.
Informes sobre el tema "Urban winds"
1
Linn, Rodman Ray, Jesse M. Canfield, Jean Luc Dupuy, Eunmo Koo, Domingo Munoz-Esparza, Francois Pimont, Jon Michael Reisner, Jeremy A. Sauer, William Scott Smith y Judith Winterkamp White. Urban Flow, Wind Energy and Fire Modeling. Office of Scientific and Technical Information (OSTI), enero de 2015. http://dx.doi.org/10.2172/1169138.
Texto completo
2
Mittal, Rajat y Tyson Hendrick. Integrated Study of Flight Stabilization with Flapping Wings in Canonical Urban Flows. Fort Belvoir, VA: Defense Technical Information Center, junio de 2013. http://dx.doi.org/10.21236/ada588171.
Texto completo
3
Journeay, M., P. LeSueur, W. Chow y C L Wagner. Physical exposure to natural hazards in Canada. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/330012.
Texto completoResumen
Natural hazard threats occur in areas of the built environment where buildings, people, and related financial assets are exposed to the physical effects of earth system processes that have a potential to cause damage, injuries, losses, and related socioeconomic disruption. As cities, towns, and villages continue to expand and densify in response to the pressures of urban growth and development, so too do the levels of exposure and susceptibility to natural hazard threat. While our understanding of natural hazard processes has increased significantly over the last few decades, the ability to assess both overall levels of physical exposure and the expected impacts and consequences of future disaster events (i.e., risk) is often limited by access to an equally comprehensive understanding of the built environment and detailed descriptions of who and what are situated in harm's way. This study addresses the current gaps in our understanding of physical exposure to natural hazards by presenting results of a national model that documents characteristics of the built environment for all settled areas in Canada. The model (CanEM) includes a characterization of broad land use patterns that describe the form and function of cities, towns, and villages of varying size and complexity, and the corresponding portfolios of people, buildings and related financial assets that make up the internal structure and composition of these communities at the census dissemination area level. Outputs of the CanEM model are used to carry out a preliminary assessment of exposure and susceptibility to significant natural hazard threats in Canada including earthquake ground shaking; inundation of low-lying areas by floods and tsunami; severe winds associated with hurricanes and tornados; wildland urban interface fire (wildfire); and landslides of various types. Results of our assessment provide important new insights on patterns of development and defining characteristics of the built environment for major metropolitan centres, rural and remote communities in different physiographic regions of Canada, and the effects of ongoing urbanization on escalating disaster risk trends at the community level. Profiles of physical exposure and hazard susceptibility described in this report are accompanied by open-source datasets that can be used to inform local and/or regional assessments of disaster risk, community planning and emergency management activities for all areas in Canada. Study outputs contribute to broader policy goals and objectives of the International Sustainable Development Goals (SDG 2015-2030; Un General Assembly, 2015) and the Sendai Framework for Disaster Risk Reduction (SFDRR 2015-2030; United Nations Office for Disaster Reduction [UNDRR], 2015), of which Canada is a contributing member. These include a more complete understanding of natural hazard risk at all levels of government, and the translation of this knowledge into actionable strategies that are effective in reducing intrinsic vulnerabilities of the built environment and in strengthening the capacity of communities to withstand and recover from future disaster events.
4
Klipp, Cheryl L. y Edward Measure. Urban Turbulence and Wind Gusts for Micro Air Vehicle Bio-inspired Designs. Fort Belvoir, VA: Defense Technical Information Center, marzo de 2011. http://dx.doi.org/10.21236/ada549371.
Texto completo
5
Brandt, Leslie A., Cait Rottler, Wendy S. Gordon, Stacey L. Clark, Lisa O'Donnell, April Rose, Annamarie Rutledge y Emily King. Vulnerability of Austin’s urban forest and natural areas: A report from the Urban Forestry Climate Change Response Framework. U.S. Department of Agriculture, Northern Forests Climate Hub, octubre de 2020. http://dx.doi.org/10.32747/2020.7204069.ch.
Texto completoResumen
The trees, developed green spaces, and natural areas within the City of Austin’s 400,882 acres will face direct and indirect impacts from a changing climate over the 21st century. This assessment evaluates the vulnerability of urban trees and natural and developed landscapes within the City Austin to a range of future climates. We synthesized and summarized information on the contemporary landscape, provided information on past climate trends, and illustrated a range of projected future climates. We used this information to inform models of habitat suitability for trees native to the area. Projected shifts in plant hardiness and heat zones were used to understand how less common native species, nonnative species, and cultivars may tolerate future conditions. We also assessed the adaptability of planted and naturally occurring trees to stressors that may not be accounted for in habitat suitability models such as drought, flooding, wind damage, and air pollution. The summary of the contemporary landscape identifies major stressors currently threatening trees and forests in Austin. Major current threats to the region’s urban forest include invasive species, pests and disease, and development. Austin has been warming at a rate of about 0.4°F per decade since measurements began in 1938 and temperature is expected to increase by 5 to 10°F by the end of this century compared to the most recent 30-year average. Both increases in heavy rain events and severe droughts are projected for the future, and the overall balance of precipitation and temperature may shift Austin’s climate to be more similar to the arid Southwest. Species distribution modeling of native trees suggests that suitable habitat may decrease for 14 primarily northern species, and increase for four more southern species. An analysis of tree species vulnerability that combines model projections, shifts in hardiness and heat zones, and adaptive capacity showed that only 3% of the trees estimated to be present in Austin based on the most recent Urban FIA estimate were considered to have low vulnerability in developed areas. Using a panel of local experts, we also assessed the vulnerability of developed and natural areas. All areas were rated as having moderate to moderate-high vulnerability, but the underlying factors driving that vulnerability differed by natural community and between East and West Austin. These projected changes in climate and their associated impacts and vulnerabilities will have important implications for urban forest management, including the planting and maintenance of street and park trees, management of natural areas, and long-term planning.