scholarly journals Wind Pressure Coefficient on a Multi-Storey Building with External Shading Louvers

2020 ◽  
Vol 10 (3) ◽  
pp. 1128 ◽  
Author(s):  
Jianwen Zheng ◽  
Qiuhua Tao ◽  
Li Li
Keyword(s):  
Natural Ventilation ◽  
Rotation Angle ◽  
Convective Heat Transfer Coefficient ◽  
Pressure Coefficient ◽  
Pollutant Dispersion ◽  
Wind Pressure ◽  
Reference Case ◽  
Climatic Regions ◽  
Wind Pressure Coefficient ◽  
Storey Building

Wind characteristics on building surfaces are used to evaluate natural ventilation of a building. As a type of building component, external shading louvers are applied in hot climatic regions to block solar radiation and provide better visual environments. The structure of external louvers can affect wind-induced characteristics, such as convective heat transfer coefficient, wind pressure and pollutant dispersion around building envelopes. This paper aims to analyze the potential ventilation capacity of a multi-storey building with shading louvers, based on wind pressure coefficient by the numerical method. A reference case was established and a previous study was applied to validate the numerical results. The rotation angle of horizontal louvers is taken from 0° to 75° in the simulation cases. The results show that average wind pressure has the greatest reduction for all floors when rotation angle turns from 60° to 75°. Ventilation openings on the stagnation zone contribute to higher ventilation rates for the windward facade with louvers. The analysis, based on multi-floor and multi-row buildings under shaded conditions, will provide a greater perspective for engineers to make optimal natural ventilation routes in multi-storey buildings with external shading louvers.

CFD Modeling of Pressure Coefficients for a Natural Ventilation Study in an Experimental Low Rise Building

2013 ◽  
Author(s):  
Robel Kiflemariam ◽  
Cheng-Xian Lin
Keyword(s):  
Natural Ventilation ◽  
Pressure Coefficient ◽  
Wind Pressure ◽  
Analytical Models ◽  
Cfd Modeling ◽  
Engineering Practice ◽  
Pressure Coefficients ◽  
Wind Pressure Coefficient ◽  
Detailed Assessment ◽  
Ventilation Rates

Mean wind pressure coefficient (Cp) is one of the major input data for natural ventilation study using building energy simulation approach. Due to their importance, they need to be accurately determined. In current engineering practice, tables and analytical Cp models only give mostly averaged results for simpler models and configurations. Considering the limitation of tables and analytical models, Computational Fluid Dynamics (CFD) could provide a means for an accurate and detailed assessment of Cp. In this paper, we make use of a relatively high resolution, detailed experiments done at Florida Intentional University to validate a CFD modeling of the pressure coefficients Cp. The results show that existing CFD model has a good agreement with experimental results and gives important information of distribution of Cp values over the surface. The local values of the Cp are investigated. In addition, the CFD derived Cp and discharge coefficient (Cd) values are utilized in semi-analytical ventilation models in order to get a more accurate value of ventilation rates.

scholarly journals The role of complex airflow simulation tools for overheatingassessment of passive houses

2021 ◽  
Vol 2069 (1) ◽  
pp. 012170
Author(s):  
V Goncalves ◽  
T Rakha
Keyword(s):  
Natural Ventilation ◽  
Cfd Simulation ◽  
Pressure Coefficient ◽  
Wind Pressure ◽  
Passive House ◽  
Modeling Tools ◽  
Simulation Tools ◽  
Wind Pressure Coefficient ◽  
Airflow Network Model ◽  
Passive Houses

Abstract Passive Houses are characterized mainly by construction concepts that greatly reduce energy usage during the winter, but that can lead to significant overheating during the hotter summer days. Since in the Passive House concept thermal comfort during the summer mainly relies on natural ventilation to provide indoor cooling, the importance of airflow modeling tools for overheating prediction needs to be investigated. This research analyzes the effect of simplifications commonly made in airflow modeling techniques on the overheating assessment of Passive Houses by collecting measured data and calibrating a thermal model with a Passive House case study. Utilizing the calibrated model, a standalone Building Energy Model (BEM), BEM coupled with an Airflow Network Model (AFN), and BEM coupled with an AFN supported by the wind pressure coefficient values obtained from Computational Fluid Dynamics (CFD) simulation were created. The outcome of each modeling approach was then compared against each other. Results showed that the default infiltration and natural ventilation input values commonly utilized in literature, when compared to those obtained from either the AFN or AFN+CFD, are significantly overestimating the natural ventilation potential of Passive House buildings, resulting in a lower number of overheating hours (39.9% decrease) and inaccurate overheating evaluation outcomes. Therefore, the paper concludes that the use of at least an AFN is necessary when estimating the overheating hours of Passive Houses.

Mean Wind Pressure Field on the Typical Large-Span Roof Structures

2012 ◽  
Vol 166-169 ◽  
pp. 19-24
Author(s):  
Fang Hui Li ◽  
Ming Gu ◽  
Zhen Hua Ni ◽  
Shi Zhao Shen
Keyword(s):  
Pressure Field ◽  
Pressure Coefficient ◽  
Wind Pressure ◽  
Pressure Data ◽  
Shape Factors ◽  
Local Shape ◽  
Wind Pressure Coefficient ◽  
The Mean ◽  
Urban Terrain ◽  
Wind Pressures

The wind tunnel tests of some typical large roofs, including a saddle roof, pitched roof and domes, are carried out with various terrains which cover suburban and urban exposures. The wind pressure data of roofs are obtained by using the synchronous multi-pressure scanning technique. The wind pressure coefficient and local shape factors of the wind load was investigated. The effects of various terrains on wind pressures of roofs are discussed. From the results, we can see mean pressures of these roofs exposed to the mean pressures exposed to the suburban terrain are 2 or 3 times those exposed to the urban terrain. And the terrains are no directly influence to the wind pressure shape factors.

Study on Characteristics of Wind Loading on Open Ended Cantilevered Roof under Typhoon

2012 ◽  
Vol 256-259 ◽  
pp. 788-791
Author(s):  
Zhi Xiang Yin ◽  
Yu Zhang
Keyword(s):  
Pressure Distribution ◽  
Pressure Coefficient ◽  
Surface Wind ◽  
Great Influence ◽  
Wind Load ◽  
Wind Pressure ◽  
Wind Loading ◽  
Load Model ◽  
Large Span ◽  
Wind Pressure Coefficient

Open ended cantilevered roof is different from enclosed roof, because its change of wind pressure distribution is complex, and the wind directions have great influence on it. Up to now, for the characteristics of the structure are very complicated, there is no appropriate wind load model can be used in design, especially under typhoon, a specific wind field. So it is necessary to study the characteristics of wind load on open ended cantilevered roofs of typhoon. Using FLUENT and Computational Fluid Dynamics technology, based on the conventional, Tianpu’s and Shiyuan’s turbulence intensity of the typhoon scenario, a numerical simulation of wind flow around a large-span cantilevered roof was carried out. Analyzed different wind angles of the wind pressure distribution regularities on large-span cantilevered roof. The paper determined the distribution of the surface wind pressure coefficient for the cantilevered roofs, as well as the wind-sensitive parts of structures.

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