Numerical Simulation And Wind Tunnel Test Research On Natural Ventilation Through Large Opening

Natural ventilation, as an important method of reducing the heat, removing the humidity, improving indoor environment and zero energy consumption, has received increasing attention in today's world. However, many factors influence natural ventilation in buildings. With many isolation and whirlpool of movement and complex opening and internal structure, passive ventilation of buildings in transition season (natural ventilation through large opening) is one of unresolved problems of research in natural ventilation in particular.The simulated results of infiltration and natural ventilation through large opening have been researched. The study shows that the resistance property of infiltration model and large openings model are different. The process of natural ventilation through large opening of Single-zone does not meet conditions of network method use, which is an important computation method of natural ventilation macroscopic models. It needs research in more detail.Energy conservation equation and numerical simulation have been combined to research the natural ventilation through large opening of Single-zone. The results of numerical simulation have been authenticated by wind tunnel test. This paper summarize the method of numerical simulation used by early members of our group, and do further research in the aspects of computing area selection and mesh partition. Similar guidelines that wind tunnel test of natural ventilation should be complied with and advantages and disadvantages of various method that the wind velocity measure have been expatiated.Firstly, energy conservation equation has conditions of use, which was taken notice in the process of natural ventilation through large opening research. To the problem of natural ventilation through large opening, the calculation section must be choose at the uniform flow or graded flow. Secondly, the driving force of natural ventilation is the difference between total pressures, which is expressed asâ–³p in the formula of discharge coefficient of natural ventilation. However orifice discharge coefficient and infiltration discharge coefficient are expressed formality similar, thisâ–³p is the difference between static pressure. Thirdly, to the problem of natural ventilation through large opening of Single-zone, energy loss caused by indoor current of air flow should be considered in the large opening discharge coefficient that deduced by energy conservation equation, and if it's necessary, the comprehensive discharge coefficient can be introduced to compute the flow rate of natural ventilation. Finally, using the numerical simulation result of large openings model of different position openings, this paper has done detailed research about the calculation section of comprehensive discharge coefficient.