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论文类型：期刊论文

发表时间：2011-10-01

发表刊物：BUILDING AND ENVIRONMENT

收录刊物：Scopus、SCIE、EI

卷号：46

期号：10

页面范围：1928-1936

ISSN号：0360-1323

关键字：Exhalation flow; Pollutant dispersion; Head posture; Breathing thermal manikin; CFD

摘要：Many researches indicate human respiration flow and background ventilation are two important aspects leading to possible respiratory disease spread. However, current studies on respiration flow and the resulted exhaled pollutant dispersion are limited, because different head postures, respiration mode, breath rate, room ventilation and so on, can exert profound impacts that are not understood very clearly. To evaluate the role of head postures on transmission of human exhaled pollutants, this study uses a computational fluid dynamics (CFD) program to study the exhalation flow of a sitting adult in a calm indoor office. Four different head postures are considered: sitting upright viewing front, sitting upright but head tilted viewing upward, sitting upright but head turned viewing the lateral, and sitting but pillowing head on a table. Based on the decay percentage of a gas concentration, the impacted scope of expired air is identified. The common posture by sitting upright viewing front is selected to investigate the change of impacted scope with increasing exhalation rates. The experimental test is also carried out using a breathing thermal manikin. This study finds out that the impacted scope of expired air under different head postures is different. The horizontal impacted distance is highly dependent on the specified threshold concentration. If a person sits around at a table and makes a deep exhalation, other people shall be apart from him/her with a larger distance to be free from the exhaled pollutant exposure, once his/her thermal plume is blocked by the table. (C) 2011 Elsevier Ltd. All rights reserved.