Experimental study on a flow behavior of flame and plume was carried out using a full scale atrium model and a reduced one having low-inlet and high-outlet openings under natural ventilation condition. Similarities between these spaces were pursued on representative ATIT in the space and on the inflow behavior which is represented by Froude number estimated at the lower opening(s). Interaction between inflow and flame/plume in the confined space was investigated using the reduced model with some variations of inlet opening arrangements. Temperatures and velocities were measured in a flame, plume, and in the confined space to characterize their vertical and horizontal distributions. Observations on visualized door jet(s), flame inclination (direction and angle), and flame heightnength were also conducted in the reduced model. Horizontal distributions of temperature and of velocity are well simulated by doubled Gaussians considering central core region and turbulent peripheral region. Decreasing mode of temperature and velocity along the ascending trajectory in of the core parts were similar to those obtained in an open space. Flame length which is affected by direct or indirect door jet(s) showed the similar manner against heat release rate but lower than these in an open space. And dimensionless flame shape was well correlated to the 3Yi3 power of dimensnsionless heat release rate modified with a Froude number. Overall entrainment into a conhed space is proportional to the 215 power of dimensnsionless heat release modified by a Grashof number. The confined flame affected with door jet(s) showed the normalized plume radius, b/z, increased about 1.9 times faster than it observed in a free plume in the lower region of the plume.

EXperiments were co 皿 ducted to u 皿 derstand the effeCts of a confined space and vcntilation on properties of plume and ncar ficld of fire seurces using 3 types ef model tunnels． The first onc is a scalcd 加 nnel with square and ／ or archod cτoss 凾 section ofO ・ 09 m2 w 醜h 且 ength of rang 洫g from O． 9 to 23mJhe second o 皿e is ， reinforccd concrctc tunmel ， ofO ， 6m wide ， 1． 8m high and 12． 8m long， The last o 皿 e is a fi 」11 ・ scaled tunnel of the cross sectio 皿al area of 5． 4 m2 With arched shape and 400m long． Temperaturcs in thc near field of flame and plume wcre mcasured changing the bulk ventilation yelocity ． Estimation on maxi 皿 um temperature and itS positie ． n that appears in the down ・ flow rcgion and ben。ath the cei g ondcr foroed ventilation wcre modeled ， a 皿 d also medeling on the corrclation fc ｝r the critical velocity was deduccd ． Froudc modeling was utilized on the relations betwecn tho cxcess temperature andlor 叩 ward vclocity along the plume axis under natural ventilation condition and that is ◎ompa 【ed With results obtained in the free beundary condition ．

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