A simple plume model induced by stack effect in a vertical shaft

After comparing the mechanism of tilted plume under stack effect with that of spill plume,the tilted plume model induced by stack effect in a vertical shaft is developed simply based on the theoretical results and a series of full-scale tests. It is shown that the two sides of plume are symmetrical and have an accordant regulation that the plume radius has a linear relation to the height z. The profile of fire plume under stack effect is similar to the windblown flame in wind tunnel,and the range of flame deflection angle is about from 50 to 60 degree.

垂直竖井中烟囱效应诱导火羽流结构的简化模型研究

本文基于质量、动量及浮力方程和一系列全尺寸实验,得到了竖井中由于烟囱效应诱导产生的倾斜火羽流结构简化模型。结果显示,火羽流结构呈对称形态,并且火羽流迎风面与背风面距离与高度呈线性关系。与隧道内的倾斜羽流不同,随着受迫卷吸作用被强化(外加来流速度增加),隧道内的火羽流倾斜角度增加;但是在垂直竖井中,由于烟囱效应导致的主动卷吸作用,迎风侧的羽流倾斜角度基本维持在50度到60度之间。

“同心鼓”颠球协作策略研究

为谋划“同心鼓”颠球协作策略,通过力学分析和数学推演,确定最佳颠球策略,提供鼓、球运动模型,计算队员的拉力大小;针对队员发力时机和力度出现误差所导致的鼓面倾斜,运用刚体转动理论,建立倾斜角计算模型,实施向量分析,构建多维度倾斜角叠加模型;研究不同方向的转动力矩合成,给出倾斜调整模型,依据鼓面倾斜度与倾斜方向设计精准调整策略。