Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Full-scale validation of CFD simulations of buoyancy-driven ventilation in a three-story office building
https://orcid.org/0000-0001-5573-8780
Abstract Computational fluid dynamics (CFD) is frequently used to support the design of naturally ventilated buildings; however, the model accuracy should be thoroughly assessed, ideally through validation with full-scale measurements. The present study aims to (1) validate transient CFD simulations with uncertainty quantification (UQ) for buoyancy-driven natural ventilation against full-scale experiments in an operational atrium building, and (2) quantify the sensitivity of the CFD results to the thermal boundary conditions. The UQ and sensitivity analysis consider uncertainties in the initial and boundary conditions for the temperatures. Considering the volume-averaged air temperature on each floor, the predictions and measurements agree well with discrepancies less than 0.3 °C. When considering the temperature averaged over smaller zones on each floor, two trends can be observed. First, in zones not adjacent to windows, the discrepancies between the CFD and measurements can be explained by uncertainty in the boundary conditions and the measurements. Second, in zones adjacent to windows, higher discrepancies are observed due to oscillations in the inflow jets just downstream of the windows, and due to geometrical simplifications in the CFD model. The sensitivity analysis demonstrates that the boundary conditions for the thermal mass surface temperature and the outdoor temperature have a dominant effect on the indoor air temperature predictions, with their relative importance varying as a function of proximity to the windows.
Highlights URANS of buoyancy-driven natural ventilation with coupled indoor/outdoor environment. URANS provides accurate predictions of floor-averaged air temperature. Small errors in regions far from windows due to uncertainty in boundary conditions. Larger errors near windows due to unsteady effects and geometrical simplifications. Thermal boundary conditions are key parameters in buoyancy-driven ventilation.
Full-scale validation of CFD simulations of buoyancy-driven ventilation in a three-story office building
https://orcid.org/0000-0001-5573-8780
Abstract Computational fluid dynamics (CFD) is frequently used to support the design of naturally ventilated buildings; however, the model accuracy should be thoroughly assessed, ideally through validation with full-scale measurements. The present study aims to (1) validate transient CFD simulations with uncertainty quantification (UQ) for buoyancy-driven natural ventilation against full-scale experiments in an operational atrium building, and (2) quantify the sensitivity of the CFD results to the thermal boundary conditions. The UQ and sensitivity analysis consider uncertainties in the initial and boundary conditions for the temperatures. Considering the volume-averaged air temperature on each floor, the predictions and measurements agree well with discrepancies less than 0.3 °C. When considering the temperature averaged over smaller zones on each floor, two trends can be observed. First, in zones not adjacent to windows, the discrepancies between the CFD and measurements can be explained by uncertainty in the boundary conditions and the measurements. Second, in zones adjacent to windows, higher discrepancies are observed due to oscillations in the inflow jets just downstream of the windows, and due to geometrical simplifications in the CFD model. The sensitivity analysis demonstrates that the boundary conditions for the thermal mass surface temperature and the outdoor temperature have a dominant effect on the indoor air temperature predictions, with their relative importance varying as a function of proximity to the windows.
Highlights URANS of buoyancy-driven natural ventilation with coupled indoor/outdoor environment. URANS provides accurate predictions of floor-averaged air temperature. Small errors in regions far from windows due to uncertainty in boundary conditions. Larger errors near windows due to unsteady effects and geometrical simplifications. Thermal boundary conditions are key parameters in buoyancy-driven ventilation.
Full-scale validation of CFD simulations of buoyancy-driven ventilation in a three-story office building
https://orcid.org/0000-0001-5573-8780
Abstract Computational fluid dynamics (CFD) is frequently used to support the design of naturally ventilated buildings; however, the model accuracy should be thoroughly assessed, ideally through validation with full-scale measurements. The present study aims to (1) validate transient CFD simulations with uncertainty quantification (UQ) for buoyancy-driven natural ventilation against full-scale experiments in an operational atrium building, and (2) quantify the sensitivity of the CFD results to the thermal boundary conditions. The UQ and sensitivity analysis consider uncertainties in the initial and boundary conditions for the temperatures. Considering the volume-averaged air temperature on each floor, the predictions and measurements agree well with discrepancies less than 0.3 °C. When considering the temperature averaged over smaller zones on each floor, two trends can be observed. First, in zones not adjacent to windows, the discrepancies between the CFD and measurements can be explained by uncertainty in the boundary conditions and the measurements. Second, in zones adjacent to windows, higher discrepancies are observed due to oscillations in the inflow jets just downstream of the windows, and due to geometrical simplifications in the CFD model. The sensitivity analysis demonstrates that the boundary conditions for the thermal mass surface temperature and the outdoor temperature have a dominant effect on the indoor air temperature predictions, with their relative importance varying as a function of proximity to the windows.
Highlights URANS of buoyancy-driven natural ventilation with coupled indoor/outdoor environment. URANS provides accurate predictions of floor-averaged air temperature. Small errors in regions far from windows due to uncertainty in boundary conditions. Larger errors near windows due to unsteady effects and geometrical simplifications. Thermal boundary conditions are key parameters in buoyancy-driven ventilation.
Full-scale validation of CFD simulations of buoyancy-driven ventilation in a three-story office building
Chen, Chen (Autor:in) / Gorlé, Catherine (Autor:in)
Building and Environment ; 221
24.05.2022
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Reduced-scale building model and numerical investigations to buoyancy-driven natural ventilation
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Performance Simulations of Hybrid Ventilation Systems in a Five-Story Office Building
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Performance Simulations of Hybrid Ventilation Systems in a Five-Story Office Building
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