抄録
In this paper we report the experimental study on the flow of smoke and air in the model anteroom in case of large air inlet and smoke outlet openings which open from floor to near the ceiling and from ceiling to near the floor respectively. The result was compared with the field experiment of similar openings and was made some supplementary discussions.
The model and the apparatus used in this experiment are the same as in part 2, except openings. Moreover, the condition of similarity assumes the same as in part 2, that is, the ratios of supply air and inflow smoke volumes to anteroom volume are equal between model and prototype, therefore, the flow l/s for the model corresponds to m3/s for the prototype.
In this experiment following results are obtained.
(1) Flow characteristics of smoke and air in the anteroom, under constant volume and optical density of inflow smoke change continuously with supply air. This flow characteristics were classified, in parts 1 and 2, to types O, A, B, C, D and E. However, in this experiment they were classified to types O, A′, C, D and E. The two layer flow was consisted of types A, B and C in parts 1 and 2, and of types A′ and C in this case, so the type B which has fully transparent lower layer was not formed. This shows that the openings of this type is inferior to those of parts 1 and 2.
(2) The limits of supply air volume keeping up to two layer flow are very different from those of parts 1 and 2. The upper limit descend and lower limit ascends with increasing smoke volume, moreover, when smoke volume exceeds 6 l/s two layer flow are not formed.
(3) The relation between mean boundary height and air smoke ratio in two layer flow coincide fairly with that obtained in part 2. The mean boundary height determined by observation agrees fairly with height estimated from temperature profile, and very well with height estimated from optical density profile.
(4) Being based on the flow characteristics of the model experiment, the results of field experiment are reexamined. Consequently, fair agreement is shown between the mean boundary heights in the model and in the field experiment with similar openings.
(5) Characteristics of temperature profile for types O, A, C, D and E do not differ markedly, so that the classification to types by temperature profile is very difficult, however, distinct classification is possible by optical smoke density profile.
(6) According to conclusions (1), (2) and (3), it can be concluded that the case of air inlet and smoke outlet openings shown in this report is the worst. Better is the case of openings in part 1 which are air inlet in lower part and smoke outlet from ceiling to floor, and the best is the case of openings in part 2 which are air inlet in lower part and smoke outlet upper part of the wall.
