| 摘要(英) |
This study used wind tunnel experiments to investigate the influence of wind speed, direction and opening size on the wind-driven ventilation with two openings on a single wall. The exchange rates Q across the openings were systemically measured by tracer gas decay method. The experimental results indicate that the dimensionless exchange rate, Q* = Q/UHA, of shear-induced ventilation (wind is parallel to the openings) is independent of the wind speed UH and opening area A. Furthermore, the exchange rate cannot be predicted by the orifice equation when the wind direction equals to 0o and 67.5o~180o, because the time-averaged pressure difference across the opening is close to zero. The fluctuating pressure across the building openings will entrain air across the opening, and the exchange rate is proportional to the root-mean-square of fluctuating pressures. For wind direction equals to 22.5o ~ 45o, since the pressure difference is much larger than fluctuating pressure, the ventilation is dominated by the pressure difference across the openings. In addition, this study also investigates the single-sided ventilation for buildings with internal partition. The exchange rate for building with internal partition is smaller than building without internal partition for wind direction equals to 0o ~ 90o. When wind direction equals to 112.5o ~ 180o, the exchange rate is independent of the internal partition wall. The ventilation rates with the internal plate can be predicted by a modified version of the resistance model of Chu and Wang (2010). |
| 參考文獻 |
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