When evaluating ventilation flow rates in wind-driven cross-ventilated building, traditional orifice model uses fixed discharge coefficients for inflow and outflow openings, which are constant regardless approaching wind direction. However, several studies have shown that the discharge coefficients vary with wind directions and opening positions. The proposed local dynamic similarity model can select discharge coefficients suitable for various wind direction conditions. The validity of the model has been evaluated in detail for various conditions of inflow openings. This paper summarizes previous studies for various conditions of inflow openings, and describes new studies for outflow openings and evaluates ventilation flow rates in two zones based on coupled simulation of local dynamic similarity model and simple network model. It also reports a simplified method for estimating dynamic pressure tangential to an opening, which is adopted as an additional parameter for the present model.
He is a professor of Architectural Engineering, Faculty of Engineering, Tokyo Polytechnic University since 1992. He earned his B.Eng. in 1971 from Nihon University and M. Eng. in 1974 from National Yokohama University and D. Eng. in 1978 from University of Tokyo. He worked as a visiting scientist with chief director W. Snyder at Fluid Modeling Division of US Environmental Protection Agency from 1992 to 1993. His current research interests include cross-ventilation, digital imaging technique and heat transfer phenomena in urban areas. At present, he is working as a group leader for the 21st COE project of Wind Effects on Buildings and Urban Environment.
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