TY - JOUR

T1 - Returning and net escape probabilities of contaminant at a local point in indoor environment

AU - Chung, Juyeon

AU - Lim, Eunsu

AU - Sandberg, Mats

AU - Ito, Kazuhide

N1 - Funding Information:
This research was partly supported by a Grant-in-Aid for Scientific Research ( JSPS KAKENHI (B) , 16H04466 ). The authors would like to express special thanks to the funding source.

PY - 2017/11/15

Y1 - 2017/11/15

N2 - The quantified recirculation of a contaminant in a local domain is an essential property of the ventilation efficiency in a room. The returning probability of a contaminant (α) generated in a local domain and its net escape probability (NEP) are essential information for understanding the structure of the contaminant concentration distribution in a room and for controlling the indoor air quality. Here, we propose the fundamental definitions of α and NEP and discuss their potential relation with the net escape velocity (NEV) concept. NEP is defined at a local point and/or local domain as the probability that a contaminant is exhausted directly through an exhaust outlet and does not re-circulate to the target local point/domain again. In a computational fluid dynamics (CFD) simulation, the minimum local domain in a room corresponds to the control volume (C.V.) of discretization; hence, NEP in a C.V. is assumed as the probability in a point without volume. In this study, the calculation results of α, NEP, and NEV distributions in a simple two-dimensional model room and a three-dimensional room with push-pull type ventilation system are demonstrated and discussed.

AB - The quantified recirculation of a contaminant in a local domain is an essential property of the ventilation efficiency in a room. The returning probability of a contaminant (α) generated in a local domain and its net escape probability (NEP) are essential information for understanding the structure of the contaminant concentration distribution in a room and for controlling the indoor air quality. Here, we propose the fundamental definitions of α and NEP and discuss their potential relation with the net escape velocity (NEV) concept. NEP is defined at a local point and/or local domain as the probability that a contaminant is exhausted directly through an exhaust outlet and does not re-circulate to the target local point/domain again. In a computational fluid dynamics (CFD) simulation, the minimum local domain in a room corresponds to the control volume (C.V.) of discretization; hence, NEP in a C.V. is assumed as the probability in a point without volume. In this study, the calculation results of α, NEP, and NEV distributions in a simple two-dimensional model room and a three-dimensional room with push-pull type ventilation system are demonstrated and discussed.

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U2 - 10.1016/j.buildenv.2017.08.028

DO - 10.1016/j.buildenv.2017.08.028

M3 - Article

AN - SCOPUS:85028576284

VL - 125

SP - 67

EP - 76

JO - Building and Environment

JF - Building and Environment

SN - 0360-1323

ER -