| Natural ventilation can create a comfortable indoor environment and significantly reduce air conditioning time,which has significant advantages in creating a healthy indoor environment and reducing building energy consumption.Classrooms in universities are densely populated and crowded,and in the post pandemic era,the air quality in classrooms is directly related to the health of students.Unilateral natural ventilation in university classrooms,as a traditional ventilation method,has always been a research hotspot for researchers due to the complexity of its airflow field.This article takes the multi opening single side natural ventilation classroom of universities in hot summer and cold winter regions as the research object,and conducts numerical simulation research on its wind environment,providing theoretical basis for the design of teaching buildings and the renovation of existing teaching buildings.The main research work is as follows:In order to study the airflow field of one-sided natural ventilation in university classrooms in hot summer and cold winter regions,classrooms at Donghu Campus of Zhejiang Agricultural and Forestry University were selected to conduct experimental research on the wind environment of full-scale one-sided natural ventilation classrooms.The distribution characteristics of building surface wind pressure and the influence of window opening degree on indoor wind speed under certain outdoor wind environment conditions were summarized,providing experimental data for further simulation and verification.The experimental results indicate that the wind pressure distribution on the building surface is relatively uniform and stable;The impact of different opening degrees on indoor wind speed is mainly reflected in the area near the opening.Compared to 1/3,opening 2/3 and fully opening increase the average wind speed at the measuring point by 7.8% and 24.1%,respectively.To further study the wind environment characteristics of unilateral natural ventilation in university classrooms,this paper combines and compensates for the advantages and disadvantages of traditional RANS and LES methods,and establishes an effective RANS/LES mixed turbulence numerical model for predicting complex flows.On this basis,a RANS/LES mixed turbulence numerical model was established using UDF programming in the one-sided naturally ventilated classroom of Donghu Campus of Zhejiang A&F University,and the commonly used k-ε Two equation models were used to numerically simulate the characteristics of classroom wind environment under three different degrees of opening,and compared with measured data for verification.The results indicate that the mixed turbulence numerical model has higher accuracy in simulating unilateral natural ventilation in university classrooms,with average wind pressure coefficient RMSE(0.026)and average normalized wind speed value RMSE(0.009)both lower than traditional k-ε Two equation model.To investigate the influence of geometric parameters of window openings on indoor ventilation in a one-sided naturally ventilated classroom,a RANS/LES mixed turbulence numerical model was used.A total of 22 operating conditions,including different sliding window openings,side hung window openings,and opening height from the ground,were selected to analyze the indoor wind environment characteristics of a one-sided naturally ventilated classroom.The relationship between geometric parameters of window openings and indoor ventilation effect was established,and the effective ventilation rate was analyzed The variation pattern of indoor average wind speed and air age at a height of 1.1 meters.The research results show that the ventilation effect of both window types increases with the degree of opening,but compared to sliding windows,the effective ventilation capacity and indoor average wind speed of side hung windows can be increased by 73.5% and 61.8%,and the maximum and average air age at a height of 1.1 meters can be shortened by 42.3% and 52.3%,respectively;When the height of the opening from the ground is 0.8m,the ventilation effect is the best.Compared to 0.9m,the maximum effective ventilation volume and indoor average wind speed can be increased by 65.4% and101.8%,with a height of 1.1m... |
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