Numerical Simulation Study On Characteristics Of Construction Indoor Natural Ventilation

Natural ventilation technology can save energy and is environmentfriendly, so it meets the requirements of energy saving and emission reduction in the building field. In the use of natural ventilation, a key issue is how to calculate the discharge coefficient and air volume. Accurate calculation or estimation air volume is very difficult because wind direction is variational in the environment where the building locates. Therefore, the research on how to calculate the discharge coefficient and estimate air volume is an important research topic. This paper simulated the interior natural ventilation of single-zone and multi-zone room.On the study of indoor's natural ventilation in monomer room, the monomer room model was structured, the ventilation in all kinds of wind attack angles was simulated making use of Renormalization group(RNG) k-εturbulence model by Fluent, the frequently-used CFD(computational fluid dynamics) software. According to the results of simulation research, the relationship between natural ventilation discharge coefficient and wind attack angle was summarized. Then two methods to estimate air volume in the room were raised, one was based on the comprehensive discharge coefficient,the other was based on the discharge coefficient of the single opening. Moreover, a comparative analysis was made between the estimated values based on the two methods and values of CFD simulation. A comparative analysis was also made between the calculated values based on the orifice model and values of CFD simulation. The two methods provided the basis of interior air volume quantitative calculation.On the study of indoor natural ventilation in multi-zone room, by simulating the natural ventilation of multi-zone room, the relationship between location and aperture ratio of partition opening was achieved. Based on the research, a method used the discharge coefficient of the single opening to estimate air volume in multi-zone room was raised. This method based on the simplified macroscopic model calculated the air volume according to the relationship between discharge coefficient and wind attack angle in every opening. This paper compared the error of estimated value. This method provided an idea to forecast natural ventilation air volume.