【作者】 李红祥；

【导师】 龚光彩；

【作者基本信息】 湖南大学 ， 供热、供燃气、通风及空调工程， 2004， 硕士

【摘要】 合理利用自然通风对于建筑节能和改善室内空气品质有重要的意义，本文首先总结了自然通风的应用与研究的几个主要研究方面及其研究现状，特别指出大开口自然通风与小开口渗透风和管流的流动机理的不同，由此引出对于传统的自然通风量的计算方法产生怀疑，因此对大气边界层中大开口建筑物的气流过程用数值方法进行了模拟。 对于数值模拟的湍流模型及方法做了归纳，总结障碍物和边界条件的处理方法，提出了自己在模拟建筑自然通风过程相应的处理方法。 通过对封闭建筑物表面的风压分布进行模拟，得到丰富的迎背风面的风压分布情况，了解到迎风面的风压分布非常不均匀，因此认为在传统的计算自然通风量时采用墙体表面平均风压不合理。 首次采用了几个不同开口大小和不同相对开口位置的矩形房间模型放在大范围的大气边界层中进行模拟，详细的模拟并分析了整个开口建筑气流从室外到室内的整个过程。 通过对不同开口房间室内外的流场进行了模拟，清楚的得到大开口的自然通风过程，部分气流从室外通过室内的实际流管，进入房间的气流能保持较大的动能直到房间出口，同时可观察到开口处的动能变化的大小，这也是分析其通风过程阻力特性的差异的基础。 通过对它们的表面风压分布模拟，发现在一定的开口面积下，开口后对封闭建筑物表面的风压分布的改变只是发生在开口处一定范围内。所以只是开口处一定面积范围内的风压对于进入房间的气流起推动作用，首次提出在工程中要采用开口处在封闭建筑物上的风压来计算自然通风量。 首次对风压作用下各种不同模型的大开口矩形房间的自然通风过程阻力特性进行了详细的模拟分析。可以比较分析不同相对开口大小和不同相对位置的通风房间的阻力特性不同，得到引起通风流量不同的原因及其影响因素。同时对自然通风流量的计算进行了一些讨论。更多还原

【Abstract】 Reasonable utilizing natural ventilation has important significant in saving buildings energy and improving IAQ. Firstly the article summarizes several main fields and current situation of natural ventilation research, and points out that the fluid mechanics of cross-ventilation with open windows are completely different from those of air infiltration through cracks and pipe flow. Thus the traditionally method of evaluating natural ventilation flow rates is under suspicion. Then the author uses the method of CFD to simulate the virtual stream tube passing though large openings and around building in boundary-layer atmosphere.The turbulent models and the methods of calculation for numerical simulation are summed up. And the same time how to deal with the obstruct region and the boundary condition are summarized.Though simulating the pressure distribution on the sealed building, it can get the abundant messages about the pressure distribution on the windward wall and the leeward wall. Thus we can learn that the pressure values on the windward face are inconsistent. So we think that it was not in reason to use mean pressure in traditionally calculating the flow rates.It is the first time to detailed simulate the virtual stream tube passing though large openings of several cubic buildings with different areas and relative position of the openings in boundary-layer atmosphere.Through simulating the steam field of the building with different opening configuration. It is observed that a kind of stream tube is formed through the building. It becomes clear that a major part of dynamic energy is preserved until outside the room and how much the energy changed around the openings. And it is the foundation to analyze the resistance properties of cross-ventilation.Through simulating the pressure distribution on the facade of the building, it can be found that the much pressure change on the sealed building only happened in and around the openings when airflow pass through the building and the openings area is in some proportion to the facade area. So we think it is only the pressure in the range of opening position inducing the air passing through the building. That it is need to use the pressure on the sealed building in the opening position for calculating the natural ventilation airflow rates is proposed in the first time.The resistance properties of the natural ventilation though several cubic buildingswith large openings in different models are detailed simulated and analyzed. We can compare and analyze the difference of the resistance properties when there are different relative opening areas and positions. Thus the factors influencing the airflow rates can be found. And the same time it is explored how to calculate the natural ventilation flow rates.更多还原