Evolution of contaminant distribution at steady airflow field with an arbitrary initial condition in ventilated space

• Published in: Atmospheric environment (1994) Vol. 42; no. 28; pp. 6775 - 6784
• Main Authors: Li, Xianting, Chen, Jiujiu
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.09.2008; Elsevier
• Subjects: Accessibility of initial condition (AIC); Analytic expression; Applied sciences; Atmospheric pollution; Distributed parameter model; Exact sciences and technology; Gas contaminant; Indoor pollution and occupational exposure; Pollution; Transient dispersion; Ventilation; Gas contaminant; Ventilation; Transient dispersion; Accessibility of initial condition (AIC); Analytic expression; Distributed parameter model; Initial condition; Pollutant behavior; Environmental factor; Air quality; Forecast model; Flow field; Transport process; Health and environment; Atmospheric pollution forecasting; Indoor pollution; Lumped parameter system; Numerical simulation; Atmospheric dispersion; Analytical solution; Concentration distribution
• ISSN: 1352-2310; 1873-2844
• DOI: 10.1016/j.atmosenv.2008.05.016

Transient contaminant dispersion is of high importance to human comfort, health and safety. Lumped parameter model is usually applied to predict the evolution of contaminant dispersion, which, however, will not be effective when the contaminant distribution is not uniform. When airflow field is steady, the contaminant concentration distribution versus time will be determined by the concentration of supply air, contaminant source and initial concentration distribution in the ventilated space. An analytic expression of distributed contaminant concentration was developed using the accessibility of supply air (ASA), accessibility of contaminant source (ACS) and accessibility of initial condition (AIC). The ASA, ACS and AIC describe the contribution of supply air, contaminant source and initial condition to any point in ventilated space, and are determined by the airflow field if the contaminant sources and initial distribution are given. The analytic expression was validated by the tracer gas measurement in a test chamber. Based on the application of the expression in typical cases, the differences as well as connections between the analytic expression and lumped model were discussed. It is shown that the analytic expression is helpful for the understanding of the contaminant evolution process and may be used to obtain effective ventilation strategy for comfort and emergency.