| 摘要: |
| 在由多个对置射流风口所构成的封闭人居环境内，对涡旋结构的认识对遏制病毒和污染物传播起到至关重要的作用。本文搭建了对置射流封闭人居空间的缩比模型， 使用PIV（Particle image velocimetry）系统对等温条件和冷却条件下的流场进行测量。在涡的视角下对流场的湍流特性进行研究，对比了不同的涡识别算法的识别效果。筛选出Liutex涡识别方法对一个摆动周期内的涡旋运动进行分析，发现逆时针和顺时针方向涡旋强度不同，最大强度分别为50和110 s-1，得出涡旋的运动、合并、湮灭会对流场结构产生影响，射流摆动的周期为3.67 s左右。由于涡对污染物具有锁定作用,本文通过涡心相对频率分布图表示污染物聚集的区域，分析得出尽管流场是非定常的，但涡的分布却相对稳定，其中CS4截面左侧涡心在同一点出现的次数高达21次。在冷却条件下污染物被锁定在更小的区域，这有助于遏制污染物的传播。 |
| 关键词: 封闭空间 通风流场 对撞射流 涡识别 |
| DOI： |
| 投稿时间：2023-10-27修订日期：2023-12-17 |
| 基金项目:北京市委组织部青年骨干人才项目 |
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| Vortex Identification in the Flow Field of Opposed Jet Occupied Enclosure Space |
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| Abstract: |
| In a occupied enclosure space formed by multiple opposed jet outlets, understanding the vortex structures plays a crucial role in controlling the spread of viruses and pollutants. This study constructed a scaled model of a occupied enclosure space with opposing jet flows, incorporating a heated floor as a heat source to create thermal plumes under cooling conditions. Particle Image Velocimetry (PIV) system was employed to measure the flow field under isothermal and cooling conditions. Studying the Turbulent Characteristics of the Flow Field from the Vortex Perspective, comparing the identification performance of different vortex identification algorithms. The Liutex vortex identification method was applied to analyze the vortex motion within one oscillation period, revealing distinct strengths in counterclockwise and clockwise directions, with maximum intensities of 50 and 110 s?1, respectively. The study concluded that the motion, merging, and annihilation of vortices influence the flow field structure, with a jet oscillation period of approximately 3.67 seconds. Due to the trapping effect of vortexes on pol-lutants, areas of pollutant accumulation can be represented through the vortex core relative frequency distribution maps. It is observed that, despite the flow field being unsteady, the distribution of vortexes remains relatively stable. Specifically, on the left side of the CS4 cross-section, the vortex core appeared at the same point up to 21 times. Under cooling con-ditions, pollutants are confined to smaller regions, which aids in containing the spread of pollutants. |
| Key words: enclosed space ventilation flow field opposed impinging jet vortex identification |
