Large Eddy Simulation of turbulent buoyancy-driven flow with alternating staggered heating walls

Li, W.; Yeoh, Guan Heng; Timchenko, Victoria

doi:10.1016/j.applthermaleng.2015.06.038

Cited by 6 publications

(4 citation statements)

References 30 publications

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“…It can change widely depending on the geometry of the flow system, with inclined slots representing one of the fundamental reference configurations (Bergman et al 2017). Inclined slots are of interest in the development of † Email address for correspondence: floryan@uwo.ca energy-efficient building ventilation systems (Wong & Heryanto 2004;Mortensen, Walker & Sherman 2011;Li, Yeoh & Timchenko 2015), passive cooling devices (Naylor, Floryan & Tarasuk 1991;Straatman, Tarasuk & Floryan 1993;Straatman et al 1994;Novak & Floryan 1995;Shahin & Floryan 1999;Andreozzi, Buonomo & Manca 2005;Mehiris et al 2017), in predicting fire propagation (Song et al 2020) and in the removal of smoke from structures (Putnam 1882).…”

Section: Introductionmentioning

confidence: 99%

“…When a forced convection component is added, an increase in the flow Reynolds number leads to rapid transition from rolls to travelling waves (Hossain & Floryan 2015b). The use of staggered heating has been reported as providing superior heat transfer in turbulent convection when compared with uniform heating (Li et al 2015).…”

Section: Introductionmentioning

confidence: 99%

“…2017). Inclined slots are of interest in the development of energy-efficient building ventilation systems (Wong & Heryanto 2004; Mortensen, Walker & Sherman 2011; Li, Yeoh & Timchenko 2015), passive cooling devices (Naylor, Floryan & Tarasuk 1991; Straatman, Tarasuk & Floryan 1993; Straatman et al. 1994; Novak & Floryan 1995; Shahin & Floryan 1999; Andreozzi, Buonomo & Manca 2005; Mehiris et al.…”

Section: Introductionmentioning

confidence: 99%

“…The use of staggered heating has been reported as providing superior heat transfer in turbulent convection when compared with uniform heating (Li et al. 2015).…”

Section: Introductionmentioning

confidence: 99%

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Patterned convection in inclined slots

et al. 2022

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An analysis of laminar natural convection in inclined slots subjected to patterned heating has been performed. The imposed heating takes a simple form characterized by a single Fourier mode combined with uniform heating. It is shown that periodic heating applied at the lower plate produces no net flow when the slot is either horizontal or vertical, but a net upward flow is generated when the slot is tilted. Periodic heating applied at the upper plate produces net downward flow in the inclined situation. The addition of uniform heating promotes the upward flow while cooling has the opposite effect. There is a critical inclination angle at which the maximum net flow rate is greatest. Dynamic and thermal boundary layers are present when the wavenumber of the imposed heating is large. The use of heating at both plates, with the same wavenumber, leads to a flow dominated by the plate exposed to a more intense heating; when the two plates are heated equally no net flow is observed irrespective of the inclination angle. Changes of the relative positions of the two patterns can change the net flow rate by up to 50 %. The intensity of the flow increases with reduction of the Prandtl number. If the heating applied to the plates is of different wavelength, but of the same intensity, a wide range of behaviours of the flow system is possible. The details of this response are sensitive to the ratio of the two wavenumbers.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…The use of staggered heating has been reported as providing superior heat transfer in turbulent convection when compared with uniform heating (Li et al. 2015).…”

Section: Introductionmentioning

confidence: 99%

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Patterned convection in inclined slots

et al. 2022

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A newly designed BIPV system with enhanced passive cooling and ventilation

et al. 2023

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Nowadays, the application of renewable energies such as solar energy in the building sector has increased notably considering the adverse impacts of climate change on human life; hence many studies have focused on the application of photovoltaic panels in buildings. In the current study, a 3D computational fluid dynamics (CFD) model has been developed to evaluate the performance of a newly designed building-integrated photovoltaic (BIPV) system. Given the negative influence of overheating on the lifespan and performance of PV panels, their passive air cooling has been studied. Further, the potential of rooftop-mounted solar panels in passive ventilation of buildings by generating natural convective currents has been explored. The developed CFD model takes into consideration the effects of radiation, conduction, and buoyancy-driven natural convective currents generated by solar PV panels which are heated due to the exposure to solar radiation heat flux. The results suggest that applying a high surface emissivity for the part of the roof beneath the PV panels intensifies the natural convective currents which in turn provides better cooling for PV panels with higher cooling effects at higher solar heat fluxes. Up to a 34% increase in the convective mass flow rate and a 3 K decrease in the mean temperature of the panels were attained by modifying the emissivity of roof surface. Such a 3 K decrease in the operating temperature of the PV panels can enhance their efficiency and lifespan by about 1.56% and 21 %, respectively. Based on the operating conditions and system characteristics, the BIPV system yielded an air change rate (ACH) in the range of 3–13 which was considered to be highly prevalent in providing the required passive ventilation for a wide range of applications. It was also observed that the flow dynamics inside the building were affected by both the amount of solar heat load incident on the solar panels and the emissivity of the roof surface behind the panels.

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