Wind Tunnel Investigations of Natural Ventilation

Cermak, Jack E.; Poreh, Michael; Peterka, Jon A.; Ayad, Samir S.

doi:10.1061/(asce)0733-947x(1984)110:1(67)

Cited by 28 publications

(12 citation statements)

References 2 publications

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“…The flow over a building is turbulent if the Reynolds number (Re) considering the building height as the characteristic length (building Re) is greater than the critical number, 2 × 10 4 and the flow entering through a window is turbulent if the Reynolds number (Re) considering the window height as the characteristic length (window Re) is greater than 300 [27]. In this study, the building's Reynolds number is 2.5 × 10 4 and the window's Reynolds number is 4.3 × 10 3 .…”

Section: Basic Flow Propertiesmentioning

confidence: 99%

Flow visualization, PIV measurement and CFD calculation for fluid-driven natural cross-ventilation in a scale model

Bangalee

Miau

Lin

et al. 2013

Energy and Buildings

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Section: Basic Flow Propertiesmentioning

confidence: 99%

Flow visualization, PIV measurement and CFD calculation for fluid-driven natural cross-ventilation in a scale model

Bangalee

Miau

Lin

et al. 2013

Energy and Buildings

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“…With the barn model height as characteristic length and the local velocities at the barn, a Reynolds number of~37.000 was achieved for the inside flow of the model, which is published in a previous study with the same model [26]. This meets the requirements of the internal Reynolds number independence on the flow within the model [27], making the wind tunnel results up scalable.…”

Section: Methodsmentioning

confidence: 70%

Opening Size Effects on Airflow Pattern and Airflow Rate of a Naturally Ventilated Dairy Building—A CFD Study

Saha

Janke

et al. 2020

Applied Sciences

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Airflow inside naturally ventilated dairy (NVD) buildings is highly variable and difficult to understand due to the lack of precious measuring techniques with the existing methods. Computational fluid dynamics (CFD) was applied to investigate the effect of different seasonal opening combinations of an NVD building on airflow patterns and airflow rate inside the NVD building as an alternative to full scale and scale model experiments. ANSYS 2019R2 was used for creating model geometry, meshing, and simulation. Eight ventilation opening combinations and 10 different reference air velocities were used for the series of simulation. The data measured in a large boundary layer wind tunnel using a 1:100 scale model of the NVD building was used for CFD model validation. The results show that CFD using standard k-ε turbulence model was capable of simulating airflow in and outside of the NVD building. Airflow patterns were different for different opening scenarios at the same external wind speed, which may affect cow comfort and gaseous emissions. Guiding inlet air by controlling openings may ensure animal comfort and minimize emissions. Non-isothermal and transient simulations of NVD buildings should be carried out for better understanding of airflow patterns.

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“…The flow around a building (bluff body) is fully turbulent when Re > 2 × 10 4 , whereas the flow of air discharging through a window (opening) would become turbulent when Re > 300 [4]. Therefore, the flows inside and around the building are turbulent unless the velocities are below the critical values.…”

Section: Computational Domain and Turbulencementioning

confidence: 99%

“…Cockroft and Robertson [3] investigated the ventilation of an enclosure through a single opening and derived a simple theoretical model to predict the airflow by measuring the wind-driven ventilation subjected to impinging air stream. Cermak et al [4] reviewed the requirements for similarity of natural ventilation in wind tunnel models and experimental methods for evaluating its effectiveness. Based on the design and position of the opening, a natural ventilation system can be divided into two categories such as the cross ventilation [5] and the single-sided ventilation [6].…”

Section: Introductionmentioning

confidence: 99%

Effects of Lateral Window Position and Wind Direction on Wind-Driven Natural Cross Ventilation of a Building: A Computational Approach

Bangalee

Miau

Lin

et al. 2014

Journal of Computational Engineering

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Energy is saved when an effective natural ventilation system can provide comfort air to the occupants in a building by replacing a mechanical ventilation system. It also minimizes the risk of the environmental pollution and the global warming. A one story, full scale building was considered to carry out a comparative study of three different cases of wind-driven natural (WDN) cross ventilation with the help of computational fluid dynamics (CFD). In each case, the location of window was changed in lateral direction to predict the probable position for optimum ventilation performance and the angle of wind was varied to check the sensitivity of the wind direction on the flow field. After validating the current methodology through two satisfactory comparisons with the experimental investigations, the governing equations subjected to the corresponding boundary conditions were solved using commercial software and then the results were analyzed. A better location for the windows in each case was proposed. The ventilation purpose was served quite well even if the wind angle was changed in a moderate range from the original design. Furthermore, the velocity components, ventilation rate, surface pressure, ventilation time, and so forth in each case were investigated and compared extensively with those in other cases.

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Wind Tunnel Investigations of Natural Ventilation

Cited by 28 publications

References 2 publications

Flow visualization, PIV measurement and CFD calculation for fluid-driven natural cross-ventilation in a scale model

Flow visualization, PIV measurement and CFD calculation for fluid-driven natural cross-ventilation in a scale model

Opening Size Effects on Airflow Pattern and Airflow Rate of a Naturally Ventilated Dairy Building—A CFD Study

Effects of Lateral Window Position and Wind Direction on Wind-Driven Natural Cross Ventilation of a Building: A Computational Approach

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