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THE WIND AND THE CITY: EVALUATING THE LIMITS TO APPLY NATURAL VENTILATION FOR THERMAL COMFORT IN DENSE URBAN SETTLEMENTS USING A COMPUTATIONAL FLUID DYNAMICS TOOL.

Leite, R. C. V.; Frota, A. B.;

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Urbanization can deeply compromise the city’s atmosphere through the modification of the environmental parameters such as air temperature and wind patterns. Therefore, great emphasis should be placed on heat generation and changes on natural ventilation conditions that directly lead to thermal discomfort, compromising building’s energetic performance. Specifically in cities with hot, humid climate, the case of Fortaleza, Ceará, Brazil (latitude 3° 43’ S), natural ventilation is the main passive strategy to obtain thermal comfort. Understanding the physical phenomenon and the aspects that influence natural ventilation process becomes crucial to objectively use the wind potential for naturally cooling of buildings. . However, it is becoming a major problem to naturally ventilate the building’s façades in dense urban centers, compromising the wind access to habitations. The airflow around buildings creates a pressure distribution over buildings façades, which it is an essential aspect to natural ventilation process. By creating high and low pressure zones over different parts of the building, the wind induces the air movement inside the building and once the city’s spatial organization directly influences building’s natural ventilation through the modification of pressure coefficients (Cp) over its surfaces. Once computational fluid mechanics is a valuable tool to analyze the wind behavior within urban areas it is widely used in researches to determine air movement characteristics of a given area or inside the buildings this tool is applied in this research, which evaluates different urban densification scenarios to determine the constructive limits that result in better or worse conditions to the air movement in high-rise apartments. The investigation is largely based on a computational Fluid Dynamics (CFD) tool to analyze the airflow around buildings and calculate the pressure coefficient and velocity field that are applied in the airflow predictions inside the apartments. The objective is to adopt a set of urban and architectural solutions in order to dissipate the heat and improve indoor thermal conditions using natural ventilation, reducing the need for artificial conditioning.

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Palavras-chave: Natural ventilation, Urban densification, Pressure coefficient, Computational fluid mechanics, Thermal comfort.,

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DOI: 10.5151/meceng-wccm2012-19803

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Como citar:

Leite, R. C. V.; Frota, A. B.; "THE WIND AND THE CITY: EVALUATING THE LIMITS TO APPLY NATURAL VENTILATION FOR THERMAL COMFORT IN DENSE URBAN SETTLEMENTS USING A COMPUTATIONAL FLUID DYNAMICS TOOL.", p. 4285-4301 . In: In Proceedings of the 10th World Congress on Computational Mechanics [= Blucher Mechanical Engineering Proceedings, v. 1, n. 1]. São Paulo: Blucher, 2014.
ISSN 2358-0828, DOI 10.5151/meceng-wccm2012-19803

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