A computational methodology for effective bioclimatic-design applications in the urban environment

Abstract

In the present paper a computational methodology for assessing and improving the microclimate in the urban environment is developed. A Computational Fluid Dynamics (CFD) model is described, which accounts for the evaporation occurring on water surfaces as well as the evapotranspiration from plant surfaces and tree foliage. Solar radiation and wind effects are also taken into account. Additionally, thermal comfort indices are implemented in the model, hence local information is provided regarding thermal sensations (bioclimatic maps). Surface temperature and air temperature at pedestrian level, are also used to characterize the microclimate. The methodology is demonstrated by means of a case study, which refers to the area of Gazi in Greece. Initially, the model is applied for simulating the airflow pattern throughout the domain of interest. The numerical results reveal the problematic areas in terms of thermal discomfort and wind effects. Based on that information advanced bioclimatic techniques are suggested to reduce severe heat stresses and to eliminate these areas. The effectiveness of the architectural interventions is tested by estimating the microclimate-indices differences compared to the existing conditions. It is concluded that the proposed methodology serves adequately for applying effective bioclimatic strategies to mitigate the Urban Heat Island (UHI) effect

Natural ventilation potential for residential buildings in a densely built-up and highly polluted environment. A case study

“…The computational domain used to enclose a volume big enough to appraise the sheltering effects from the surroundings has been set to 4100 x 2600 x 900 m 3 (see Figure 2). The inlet, lateral and upper boundaries are placed at a distance over 4Hmax from the building complex, while the outlet boundary is located 8Hmax far from the area of interest, being Hmax the maximum building height of the domain [41]. For the sake of keeping reasonable simulation times without affecting accuracy, an independence grid-size test has been carried out on the computed Coefficient of pressure (Cp) values for a windward surface of a building located 1.1 km upstream.…”

Status Thermal Comfort Pada Lingkungan Atmosfer Permukiman Di Wilayah Kecamatan Denpasar Barat

“…Menyediakan kolam tampungan skala besar yang sangat baik dalam penyerapan panas yang membantu peningkatan thermal comfort lingkungan atmosfer permukiman di wilayah Denpasar Barat. Wilayah yang memiliki potensi untuk digunakan sebagai lokasi kolam tampungan skala besar adalah Desa Pemecutan Kelod yang berdekatan dengan tiga sumber air permukaan, yaitu Tukad Badung, Tukad Teba dan Tukad Mati; 5pengunaan fitur-fitur air seperti air mancur, kolam air, aliran air dan air dangkal pada ruang terbuka dapat menghilangkan panas perkotaan yang ekstrem melalui sistem pendinginan evaporatif (Stavrakakis et al, 2012). Fitur-fitur air ini dapat diterapkan di lokasi-lokasi lansekap yang tersebar di wilayah permukiman Denpasar Barat; (6) Penggunaan material yang memiliki albedo tinggi dengan kemampuan permukaan untuk memantulkan radiasi matahari yang masuk pada lingkungan permukiman adalah teknik yang sangat efektif untuk mengurangi efek dari lingkungan termal (Fintikakis et al, 2011).…”

Numerical simulation of diurnally varying thermal environment in a street canyon under haze-fog conditions

“…They found high shading level in outdoor environments extends the continuity of the acceptable thermal condition. Stavrakakis et al (2012) proposed a CFD model to assess the microclimate in urban environment, in which the plant evaporation, solar radiation and wind effects are taken into account. Their numerical results can effectively reveal the problematic areas in terms of thermal discomfort and wind effects.…”