Effects of roof configuration on natural ventilation for an isolated building

Lip Kean Moey; Man Fai Kong; Vin Cent Tai; Tze Fong Go; Nor Mariah Adam

doi:10.15282/jmes.15.3.2021.15.0659

Authors

Lip Kean Moey Centre for Modelling and Simulation, Faculty of Engineering, Built Environment & Information Technology, SEGi University, 47810, Selangor, Malaysia. Phone: +60361451777
Man Fai Kong Faculty of Engineering, Built Environment & Information Technology, SEGi University, 47810, Selangor, Malaysia
Vin Cent Tai Centre for Modelling and Simulation, Faculty of Engineering, Built Environment & Information Technology, SEGi University, 47810, Selangor, Malaysia. Phone: +60361451777
Tze Fong Go Centre for Advance Materials and Intelligent Manufacturing, Faculty of Engineering, Built Environment & Information Technology, SEGi University, 47810, Selangor, Malaysia
Nor Mariah Adam Department of Basic Science and Engineering, Universiti Putra Malaysia Bintulu Sarawak Campus, 97008, Sarawak, Malaysia

DOI:

https://doi.org/10.15282/jmes.15.3.2021.15.0659

Keywords:

natural ventilation, roof configuration, computational fluid dynamics, steady RANS, ventilation rate

Abstract

Numerical analyses based on CFD steady RANS were conducted to investigate the effects of roof configuration on wind-induced natural ventilation for an isolated roofed building. Gable roof and saltbox roof building models were tested with 15˚, 25˚, 35˚ and 45˚ roof pitch in present study. The flow field information and flow characteristics were obtained from the contours and plots generated by CFD. In accordance to the increment of roof pitch, the turbulence kinetic energy and mean velocity ratio show vigorous response. The flow separated at the windward corner do not reattach onto the roof, thus induced higher velocity gradient and form a large vortex at the roof ridge. The vortices behind then building caused by the flow separation at the roof ridge extend along the mixing layer and spread up to the roof. The pressure differences mainly rely on the roof shapes. Greater pressure differences between the upstream, interior and downstream was observed in saltbox roof cases. This is due to the extended roof height which boosted the impinging effect caused by the incoming wind. Generally, the saltbox roof configuration exhibit better performance than gable roof in terms of the measured parameters.

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Effects of roof configuration on natural ventilation for an isolated building

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