On The Effect Of The Shape Of Buildings And Chimneystacks On Ventilation And Pollutant Dispersion

Abstract

The purpose of this work is to investigate the modifications induced by the change of the roof shape in the flow field, inside and above the buildings, with an attention to their capability to modify the air quality and the dispersion of pollutants released from chimneystacks. We have carried out laboratory experiments on arrays of identical buildings, with symmetrical dual-pitched or flat roofs, and chimneystacks of different heights and positions. The experiments have been carried out in a close-loop water-channel, where two non-intrusive and quasi-continuous in space Digital Image Analysis technique have been implied to measure the velocity fields (Feature Tracking Velocimetry) and the concentration fields (Laser Induced Visualization). Results have highlight the meaningful role of gabled roofs in modifying turbulence, which increases the air exchange rate between the street canyon and the outer flow, but, in some conditions, they increase the dragging of pollutant inside the canyon. These results can have an immediate practical impact on the building design and on planning strategies, as the roof shape can be a useful tool to enhance natural ventilation and pollutant, humidity and/or heat dispersion, i.e. the air quality in urban and industrial areas.

Envelopamento Vegetal em Cânions Urbanos

“…Com a combinação dos fatores de ventilação e da quantidade de fontes poluentes -como resíduos veiculares -os cânions urbanos com elevada razão H/W possuem, usualmente, alta concentração de poluentes e baixa capacidade de dispersão (Ferrari et al, 2019). Duas formas de mitigação dessas situações são a mudança da geometria urbana, aumentando o fluxo de ar dentro do cânion, e a inclusão de vegetação, funcionando como filtro natural destes poluentes (Speak et al, 2012).…”

Construction Analysis of Housing’s Roof in Gorontalo City

“…(Yassin, 2011). Shape, angle and height of the roof are the most importance factors to assess air quality in urban an environment (Ferrari et al, 2019;Liu et al, 2019;Yassin et al, 2022) Roof shape contribute to the energy performance of a building. A domed roof is more energy efficient compared to pitched roofs, flat, and vaulted roofs.…”

A Preliminary Study On The Inclination And Shape Of Jets Issuing From An Orifice In The Lateral Wall Of A Pipe

“…al., 2015[24],Ferrari et al., 2018a [25] and 2018b[26], [27], [28]), wave position(Ferrari et al, 2016 [29], Gallerano et al (2019)[30]), flow velocity(Querzoli, 1996 [31], Badas and Querzoli, 2011 [32], Simone et al, 2013 [33], Garau et al, 2018 [34], Badas et al (2019) [35]) and acceleration (Ferrari et al, 2007 [36], Ferrari and Rossi, 2008 [37], Ferrari et al, 2008 [38], Lardeau et al, 2008 [39], Rossi et al, 2009 [40]). Among the engineering fields of interest, the DIA techniques have been employed in the civil and industrial field (such as in the present paper), in the environmental field (Ferrari et al, 2016 [41], Badas et al, 2017 [42], or in Garau et al, 2017 [43], Di Bernardino et al (2017) [44], Ferrari et al, 2017 [45], Garau et al, 2018 [46], Badas et al, 2019 [47]) and biomedical fields (Badas et al, 2015 [48], Espa et al, 2012 [49], Querzoli et al (2019) [50]).…”