10.2190/U4J5-MGJ7-MECJ-GLK1 U4J5MGJ7MECJGLK1 45 NUMERICAL STUDIES ON THERMALLY-INDUCED INDOOR AERODYNAMICS IN A COMPARTMENT WITH NATURAL VENTILATION 45 72 20050531 20050531 20050531 20050531 U4J5MGJ7MECJGLK1.pdf http://baywood.metapress.com/link.asp?target=contribution&id=U4J5MGJ7MECJGLK1 1 Q. KUI W. K. CHOW S. L. LIU The Hong Kong Polytechnic University, China Harbin Engineering University, China Air flow induced by a point heat source in a natural ventilated compartment will be studied in this article. Three models, fully-mixed model, water-fully box model, and empty air-fully box model, on air flow in a chamber reported in the literature were reviewed. With a point heat source located at the center of the compartment, two different cases with and without walls were considered. A two-layer zone modeling approach with an upper hot air layer and a lower cool air layer is assumed. Two such zone models, Model 1 and Model 2, were developed: Model 1 is for a compartment without any walls. Model 2 is for an enclosed compartment with adiabatic walls, but with two openings: one at the top and the other at the bottom. Air flow induced by a point heat source in the natural ventilated compartments is solved. Volume flow rate equations and two-layer temperature difference equations were derived. Equations in the developed zone models were solved by the symbolic mathematics. The relationship between the neutral plane height and the outlet area was drawn. Results are compared with those predicted by Computational Fluid Dynamics. It is found that the two new models give results agreed fairly well with Computational Fluid Dynamics. C. S. Yih, Fluid Mechanics: A Concise Introduction to the Theory, West River Press, Ann Arbor, Michigan, 1977. D. Etheridge and M. Sandberg, Building Ventilation: Theory and Measurement, John Wiley & Sons, Chichester, 1990 W. D. Baines, J. S. Turner, and I. H. Campbell, Turbulent Fountains in an Open Chamber, Journal of Fluid Mechanics, 212, pp. 557-592, 1990. P. F. Linden, Emptying Filling Boxes: The Fluid Mechanics of Natural Ventilation, Journal of Fluid Mechanics, 212, pp. 309-335, 1990. K. T. Andersen, Theoretical Considerations on Natural Ventilation by Thermal Buoyancy, ASHRAE Transactions, 101:2, pp. 1103-1117, 1995. G. M. J. Davies and P. F. Linden, The Effects of Headwind on Buoyancy-Driven Flow through a Doorway, 3rd International Conference on Air Distribution in Rooms, ROOMVENT '92, 3, pp. 419-433, 1992. P. Cooper and P. F. Linden, Natural Ventilation of an Enclosure Containing Two Buoyancy Sources, Journal of Fluid Mechanics, 311, pp. 153-176, 1996. P. F. Linden and P. Cooper, Multiple Sources of Buoyancy in a Naturally Ventilated Enclosure, Journal of Fluid Mechanics, 311, pp. 177-192, 1996. W. K. Chow, Assessment of Thermal Environment in an Atrium with Air-Conditioning, Journal of Environmental Systems, 25:4, pp. 409-420, 1997. Y. Li, Buoyancy-Driven Natural Ventilation in a Thermally Stratified One-Zone Building, Building and Environment, 35, pp. 207-214, 2000. G. Cox, Combustion Fundamentals of Fire, Academic Press, New York, 1995. MATLAB Version 5 User's Manual, The MathWorks Inc., Massachusetts, 1997. MAPLE V Version 5.1 User's Manual, Waterloo Maple Inc., Ontario, Canada, 1998. PHOENICS Version 3.2 User's Manual, Concentration, Heat & Momentum Limited, London, United Kingdom, 1998. H. Rouse, Gravitational Convection from a Boundary Source, Tellus, 4:3, pp. 201-210, 1954.