Studies on building layout for effective cross-ventilation

为了更好地利用交叉通风，对建筑物内部和周围的湍流流动进行了数值模拟和风洞试验。湍流的数学模型采用k-e两方程模型。主要研究结果如下：(1)对高层建筑周围空气流动的数值模拟结果与风洞试验中串联式热线风速仪测量到的整个模拟区域的风速矢量分布具有较好的一致性。(2)朝向两间房屋狭小空间的墙体上的风压系数大于单栋房屋侧墙上的风压系数。房间缝隙越窄，墙体内风压变化越大。(3)在所有的风向情况下，当建筑物覆盖率较大时，规则排列的低层房屋的所有墙体上的风压系数绝对值都较小，且接近于0。(4)…高层建筑模型对建筑模型周围25%建筑覆盖率规则排列的低层房屋模型墙体风压的影响越大，建筑模型越高。(5)当高层建筑模型的风压系数较高时，位于高层建筑模型迎风侧的低层房屋模型的风压系数较大，而位于背风侧的低层房屋模型的风压系数较小。(6)为了更好地分析模型建筑中由外向内的连续气流现象--交叉通风，尝试了采用局部细化技术的数值模拟方法。(7)交叉通风率的估计需要模型建筑所有开口处的总压降系数，因为交叉通风通过室内空间的气流是守恒的。用常规方法根据孔口静压差和流量系数计算的通风量比实际的交叉通风量小19-38%。(8)模型建筑物进口总压降系数和出口总压降系数均小于1.0，出口总压降系数约为前者的一半。相同形状的隔板位置不同，隔板开口处的总压降系数变化较大。尤其是当隔板被设置为交叉通风的屏障时，它就会很大。较少

Several cases of numerical simulation and wind tunnel tests of turbulent air flows in and around buildings were carried out for better utilization of cross-ventilation.k-e 2-equation model is adopted as a mathematical model of turbulence. The main results are summarized as follows : (1) The result of numerical simulation of an air flow around a high-rise building indicates good agreement with the distribution of wind velocity vectors in the whole simulation area measured by a tandem-type hot wire anemometer in a wind tunnel test. (2) The wind pressure coefficients on the walls facing to a narrow space between two houses are larger than those on a side wall of a single house. When the inter house gap is narrower, the change of the wind pressure in the wall is greater. (3) The absolute values of wind pressure coefficients on all the walls of regularly aligned low-rise houses are smaller and close to 0, when the building coverage ratio is larger in all the cases of wind direction. (4) The … More influence of a high-rise building model on the wind pressure on the walls of low-rise house models which are aligned regularly with a building coverage ratio of 25% around the building model becomes greater, when the building model is higher. (5) The wind pressure coefficients of low-rise house models located in the windward side of a high-rise building model are larger and those in the leeward side are smaller, when the building model is higher. (6) Numerical simulation methods employing partial refine technique are attempted successfully for the better analysis of cross-ventilation which is a continuous air flow phenomenon from the outside to the inside of a model building. (7) The estimate of a cross-ventilation rate needs total pressure drop coefficients at all the openings of a model building, because the air flow by cross-ventilation passing through the indoor space conserves its kinematic energy. The ventilation rates calculated by the conventional method based on static pressure differences and discharge coefficients of openings are smaller than actual cross-ventilation rates by 19-38%. (8) The total pressure drop coefficients at the inlet opening and that at the outlet opening of a model building are smaller than 1.0, and the latter is about a half of the former. The total pressure drop coefficients at the openings of partitions change greatly by the position of the partitions of the same shape. Especially, it is large when the partition is located to be a barrier of cross-ventilation. Less