Dual steady transports of heat and moisture in a vent enclosure with all round states of ambient air

• Published in: International journal of heat and mass transfer Vol. 55; no. 23-24; pp. 6979 - 6993
• Main Authors: Zhao, Fu-Yun, Rank, Ernst, Liu, Di, Wang, Han-Qing, Ding, Yu-Long
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.11.2012; Elsevier
• Subjects: Ambient air; Applied sciences; Aridity; Building technical equipments; Buildings; Buildings. Public works; Combined heat and moisture transfer; Enclosure; Enclosure flow; Environmental engineering; Exact sciences and technology; Heat transfer; Mass transfer; Moisture; Non-unique flows; Steady flow; Transport; Ventilation. Air conditioning; Vents; Enclosure flow; Ambient air; Non-unique flows; Combined heat and moisture transfer; Air flow; Buildings; Ventilated wall; Humidity; Numerical simulation; Modeling; Heat transfer; Natural ventilation
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/j.ijheatmasstransfer.2012.07.011

Combined natural convective heat and moisture transports in a moist-air-filled enclosure with four free vent ports are numerically investigated. Four situations of ambient air states, hot and humid (I), hot and arid (II), cold and arid (III), and cold and humid (IV), are taken into consideration. Convective transports of semi-enclosed air, heat and moisture are respectively analyzed using the contours of streamfunction, heatfunction and massfunction, in addition to the isotherms and iso-concentrations. Overall convective heat transfer rate (Nu) and moisture transfer rate (Sh) of the internal concentrated heat and moisture source have been correlated with the thermal Rayleigh number respectively within the domain of the heat transfer driven flows and that of moisture transfer driven flows. When different initial convective flow conditions were imposed in the cases (I) and (IV), dual steady flow states of semi-enclosed heat and moisture convection are observed, and heat and moisture transport potentials can be enhanced or inhibited depending on the flow solution branches. These results can be adopted to guide the design of natural ventilation in the humid regions.