Empirical and numerical study of pollutant leakage caused by human arm movement through machine enclosure

• Published in: Journal of cleaner production 2022-12, Vol.379, p.134726, Article 134726
• Main Authors: Chen, Chuanming, Lai, Dayi, Chen, Qingyan
• Format: Article
• Language: English
• Subjects: CFD; Empirical model; Enclosure; Human arm movement; Pollutant leakage
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2022.134726

The manufacturing industry consumes a large quantity of energy for ventilation to remove pollutants and heat generated during production processes. However, workers’ arm movements may cause pollutant leakage and reduce ventilation efficiency. This lead to increased energy consumption on ventilation, but their impacts have not been considered in previous studies. This investigation used a validated computational-fluid-dynamics (CFD) program to study the human arm induced pollutant leakage, and an empirical formula was proposed to predict the leakage. Four types of human arm movements were studied: (1) no movement, (2) up-down movement, (3) horizontal in-out movement, and (4) inclined in-out movement. The inclined in-out movement caused the most pollutant leakage, and a higher arm-moving velocity increased the pollutant leakage amount. Compared with the results of CFD simulation, the formula underestimated the leaked volume by 8–31% and the pollutant leakage amount by 9–32%. In summary, this study found that the pollutant leakage occurred in the wake behind the moving arms, and the proposed empirical formula provided a rapid and acceptable method for evaluating the pollutant leakage. With this work, clean environment in industrial buildings could be realized with lowered energy consumption, thus achieving sustainable development. •Pollutant harms workers' health and increases energy consumption.•Human arm movements in, out, and within the machine enclosure caused significant pollutant leakage.•LES showed good accuracy while predicting wake characteristics behind arms.•Higher arm-moving velocity and larger projected area caused more leakage.•Empirical formula was proposed for fast evaluation of pollutant leakage.