本論文主要探討出流控制置換式通風對於流場的影響, 並和入流控制置
換式通風作比較。研究工作以縮尺壓克力模型進行鹽浴實驗, 在縮尺壓克力
模型中間放置隔板, 形成兩個相同截面積的相連房間。實驗組別根據中間隔
板開口面積大小分為Ex(I) 和Ex(II) 兩系列, Ex(I) 中間隔板開口面積
為 cm2, Ex(II) 中間隔板開口面積為51 cm2, 又兩實驗系列依抽取流量,
Qex = 1、2、3和4 LPM, 可再分為四組實驗。浮力源房間頂部供應固定
流量之鹽水, 抽水裝置則設置在底部; 非浮力源房間頂部有一開口使清水自
然流入。實驗結果顯示, 抽取流量增加, 會使點熱源和交界面高度的距離增
加, 密度層的密度值減少。Ex(I) 因中間隔板開口面積較小, 入流動量較大,
因此在界面有較顯著的擾動; Ex(II) 中間隔板開口面積較大, 入流動量較
小, 所以分層較為穩定。比較出流控制置換式通風和入流控制置換式通風流
場的結果顯示, 入流控制置換式通風的密度層在水平方向分布較均一, 光度
值為0.5、0.6、0.8的輪廓線呈現水平分布, 其中等光線在Lambert-Beer
Law 上為濃度表現, 入流控制置換式通風在相同水平高度擷取的光度值也
呈水平分布; 出流控制置換式通風受匯流作用影響, 匯流影響半徑和在匯流
影響半徑上之速度隨抽取流量而增加, 使得匯流口跟遠離匯流口位置的光
度差越來越顯著, 造成密度層流體在水平方向有顯著的梯度, 等光線為0.5、
0.6、0.8在接近匯流口時呈現垂直分布。當距離出口位置越遠, 在相同高度
水平擷取範圍的光度值越小, 密度值越大。

The purpose of this research is to study the extraction mechani-
cal displacement ventilation and investigate the effects of the supply
source and the extraction sink on mechanical displacement ventila-
tion. The salt-bath technique is employed to conduct the experi-
ments by using the acrylic reduced-scale model. A partition with an
opening was placed in the middle of the acrylic reduced-scale model
to divide the model into two individual chambers. According to
the partition opening area, the experimental are categorized as two
series, Ex(I) and Ex(II). The partition opening area of Ex(I) and
Ex(II) is and 51 cm2 respectively. Each series includes four differ-
ent extraction flow rate, Qex = 1,2,3 and 4 LPM. The density plume
as a buoyancy source is placed on the top of the forced room and
extraction device is installed on the bottom of the forced room. The
environmental fluid flow throw in the opening on the top of the un-
forced room. Experimental results show that as the extraction flow
rate increases, the distance from the plume source to the interface
height increases; and the density of the buoyancy layer decreases.
The stratification stability highly depends on the inflow momentum.
The smaller partition opening area induces the larger inflow momen-
tum, such as Ex(I) series of experiments. The mixed layer of Ex(I)
is more noticeable than that of Ex(II) for a give extraction flow rate.
Comparisons between extraction mechanical displacement ventila-
tion and supply mechanical displacement ventilation show that the
intensity contour of the supply mechanical displacement ventilation
is almost horizontal and that means the intensity is the same at the same level. The influence of sink on extraction mechanical dis-
placement ventilation is apparent. When the extraction flow rate
increases, the sink effect radius, rex, and the sink velocity at the sink
effect radius, Vs(rex), increases. It causes the intensity difference be-
tween the sink outlet and the distance away from it at the same level
become sigificant. The intensity contour near the sink outlet has a
vertical distribution. As the distance away from the outlet increases,
the intensity at the same level decreases, i.e. the density increases.

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