Even if there is only one opening with the room and there is no temperature difference between inside and outside, the room will be ventilated due to external natural wind. It is said that there are some mechanisms of the wind-forced ventilation through a single opening. Two kinds of theoretical approach have been tried before. The one is pulsation theory and the other is mixing layer theory. In this paper, these theories are reviewed and the validity of each theory are examined by means of wind tunnel test. As a result the pulsation could not be applicable to the conditions of various wind directions. Then experimental equation is derived from the wind tunnel test using a small building model with a single circular opening. In addition, new approaches using CFD and PIV to know the airflow inside the single opening precisely will be tried and the dominant frequency of the velocity fluctuation were examined.
Dr. Yamanaka is an Associate Professor at the Department of Architectural Engineering, Graduate School of Engineering, Osaka University. He was born at Osaka in 1959, and graduated from Osaka University in 1982. He received his ph. D. in Engineering from Osaka University in 1993. The theme of his doctoral thesis is "Design method of wind-forced ventilation taking account of the turbulence of natural wind. Although he has been studying natural ventilation for over 20 years, his recent research ranges widely in air environment as follows: displacement ventilation, hybrid ventilation with wind-forced ventilation and floor supply air-conditioning system, kitchen ventilation (ceiling ventilation), utilization of ceiling fan for the control of air-conditioning, solar chimney and odor evaluation.
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