本論文探討兩相連通房間使用機械抽取設備所導致的置換通風型態。 兩
個相連通房間, 其中一個房間包含一個密度源點 (浮力源點), 此房間稱為浮
力源房間, 另一個房間則設置一抽取系統, 此房間稱為抽取房間。 本論文分
別探討串聯模型與並聯模型, 串聯模型只有單一孔口連接外界環境與浮力
源房間, 抽取房間則無孔口連接外界環境; 並聯模型則額外增加一個連接環
境與抽取房間的孔口, 兩個房間有各自的孔口連接至外界環境。 分析理論考
量室內外的壓力分佈, 以及使用點升流物理模型、 體積流率和浮力通量守
恆方程式, 理論解析的結果包括兩個房間的界面層高度、 縮減重力以及各
個房間的體積流率。 實驗室的類比實驗使用鹽浴法模擬置換式通風型態, 使
用兩相連房間的縮尺壓克力模型。 根據流體的驅動力和模型的連結設計, 實
驗系列區分為串聯自然通風、 串聯機械通風與並聯機械通風三個系列。 系列
一, 串聯自然通風實驗, 改變出流孔口的位置, 重複與驗證之前的研究工作
成果; 系列二, 串聯機械通風實驗; 系列三, 並聯機械通風實驗。 系列二與
系列三, 依據抽取流量,Qex為9,18和27 cm3s−1, 各別有三組實驗。 實驗結
果顯示於串聯自然通風條件下, 增加出流孔口與浮力源點的高度差, 浮力源
房間之體積流率也會對應地增加, 類似於串聯機械通風條件下, 增加抽取體
積流率的效果。 在並聯機械通風中, 當抽取房間的鹽水層完全覆蓋中間孔口
時, 外界環境與抽取房間之間則無任何流量。 在串聯機械通風條件下, 浮力
源房間之體積流率和機械控制的抽取體積流率相同, 而在並聯機械通風條
件下, 浮力源房間之體積流率則有上限值。 本研究也發現, 在串聯機械通風
時, 中間孔口提供的動量會擾動抽取房間流體的分佈表現, 進而影響抽取房
間的界面層高度。 在大流量的串聯機械通風條件下, 中間孔口與抽取設備的
位置皆會影響抽取房間內的流體分層表現。

The purpose of this research is to study the mechanical extraction
ventilation in two connected rooms. In two connected rooms,
there is a heat source (buoyancy source) in one of two rooms, which
is denoted as the forced room, and there is an extraction device in
the other room, which is denoted as the extraction room. The seriesconnected
and parallel-connected models are investigated. The seriesconnected
model has an opening between the ambient and the forced
room. The parallel-connected model has one additional opening between
the ambient and the extraction room, and two rooms have
their individual connecting openings to the ambient. In the theoretical
analysis part, the solutions of physical parameters are obtained
by using the pressure differences at the connecting openings, the
plume model and the conservation equations of mass and buoyancy.
A two-room reduced-scale acrylic model is used to conduct the laboratory
experiments by using the salt-bath technique. According
to the ventilation type and the connection type of the model, experimental
cases are categorized into three sets, Set 1, the seriesconnected
model of natural ventilation; Set 2, the series-connected
model of mechanical ventilation; Set 3, the parallel-connected model
of mechanical ventilation. Set 1, natural ventilation, repeats the previous
research work by changing the exit opening location. Either
of Set 2 and Set 3 includes three experiments with different extraction
flow rates, Qex = 9, 18 and 27 cm3/s. Experimental results
of natural ventilation in the series-connected model show when the
vertical distance between the buoyancy source and the exit opening
increases, the volume flow rate of the space also increases, and it
achieves the same effect as that of increasing the extraction volume
flow rate in mechanical ventilation in the series-connected model.
In the parallel-connected model of mechanical ventilation, there is
no flow between the ambient and the extraction room when the internal
connecting opening is covered by the dense salt water layer
of the extraction room. The volume flow rate of the forced room
is always the same as the mechanical extraction volume flow rate
in the series-connected model, but has a limit value in the parallelconnected
model when the mechanical extraction flow rate is large
enough. This research also finds that the momentum flux from the
internal connecting opening causes the different flow stratification
in the extraction room in the series-connected model of mechanical
ventilation when the flow rate is large enough. Therefore in the
series-connected model of mechanical ventilation, the internal connecting
opening and the extraction sink location both influence the
flow stratification in the extraction room for the large extraction flow
rate case.

[1] G.R. Hunt, P.F. Linden. (1999), The fluid mechanics of natural
ventilation-displacement ventilation by buoyancy-driven flows
assisted by wind. Building and Environment, 34, 707-720.
[2] G.R. Hunt, P.F. Linden. (2004), Displacement and mixing ventilation
drivenby opposing wind and buoyancy. J. Fluid Mech.,
527, 27-55.
[3] Holford, J. M. and Hunt, G. R. (2003), Fundamental atrium
design for natural ventilation. Building and Environment, 38,
409-426.
[4] Y.J.P. Lin, T.H. Tsai. (2013), The push-type displacement ventilation
in two series-connected chambers. Building and Environment,
62, 89-101.
[5] W.K. Chow, L. Yi, C.L. Shi, Y.Z. Li, R. Huo. (2006), Mass
flow rates across layer interface in a two-layer zone model in an
atrium with mechanical exhaust system. Building and Environment,
41, 1189-1202.
[6] L. Yi, W.K. Chow, Y.Z. Li, R. Huo. (2005), A simple two-layer
zone model on mechanical exhaust in an atrium. Building and
Environment, 40, 869-880.
[7] G.R. Hunt, P. Cooper, P.F. Linden. (2001), Thermal stratification
produced by plumes and jetsin enclosed spaces. Building
and Environment, 36, 871-882.
[8] Hunt, G. R. and Kaye, N. G. (2001), Virtual origin for lazy
turbulent plumes. J. Fluid Mech, 435, 377-396.
[9] Lee, J. H. W. and Chu, V. H. (2003), Turbulent jets and plumes.
Kluwer Academic Publishers, ISBN-10: 1-4020-7520-0.
[10] 林志龍, 2012, 探討置換式通風對於室內環境流場分層的影響。 台灣科
技大學碩士論文。
[11] 蔡宗翰, 2011, 兩個串聯房間浮力驅動通風之研究。 台灣科技大學碩士
論文。
[12] 余育汶, 2014, 探討入口檔板孔隙率對排空房間的影響。 台灣科技大學
碩士論文。
[13] 吳佳盈, 2015, 探討出流控制置換式通風。 台灣科技大學碩士論文。
[14] S. J. Kwon and I. W. Seo (2005), Reynolds number effects on
the behavior of a non-buoyant round jet. Experiments in Fluids,
38, 801-812.
[15] Kumagai, M. (1984), Turbulent buoyant convection from a
source in a confined two-layered region. J. Fluid Mech., 147,
105-131.
[16] P.F. Linden. (1999), The fluid mechanics of natural ventilation.
Annu. Rev. Fluid Mech., 31, 201-238.