建筑火灾区域模拟竖孔流动的计算

本文根据建筑火灾双层区域模拟思想，给出其常微分控制方程组，并分析了其压力求解方法，然后，运用伯努力利方程推导了相邻房间通过矩形竖孔（门或窗）的质量流率计算公式，还讨论了竖孔流动中性面产生条件。在此基础上，结合一两房间、两孔建筑中烟气运动实例，运用Ｃ．Ｗ．Ｇｅａｒ刚性稳定算法对火灾发展及烟气流动过程进行了数值模拟；给出各竖孔中性面位置、数量和各主环境之间通过竖孔的质量流率；还给出各房间气体平均温升、

Calculation of the flow through a vertical vent in a zone fire model

From the basic idea of the two-layer zone fire model,the ordinary differential governing equations are given,and the relevant calculation method of pressure is analyzed. Then,Bernoulli's equation is applied to derive the formula for calculating the mass flow rate through a vertical rectangular vent(door of window)between the neighboring rooms and the condition of neutral-plane formation is discussed.On the above basis,the process of fire growth and smoke spread in a two-room and two-vent building is numerically simulated with C.W.Gear's stiffly stable algorithm.The position and number of neutral planes as well as the relevant mass flow rates are calculated. Additionally,the numerical and experimental results of the average temperature rise and interface height of each room as well as the pressure difference between the two rooms near the ceiling are presented.