The fluid dynamics of an underfloor air distribution system
The fluid dynamics of an underfloor air distribution system
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DOI：
10.1017/s0022112006009414
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发表时间：
2006-05-10
影响因子：
3.7
通讯作者：
Linden, P. F.
中科院分区：
文献类型：
--
作者：
Liu, Q. A.;Linden, P. F.
本文讨论了地板送风（UFAD）通风系统的流体动力学，与传统的空调系统相比，冷空气是从地板上的扩散器，而不是从头顶上的通风口。为了产生更真实的模型UFAD系统，我们扩展以前的工作，简化系统包括一个单一的热源在地板上的水平和一个单一的冷却扩散器，多个冷却扩散器和一个单一的热源位于地板以上的不同高度的情况下。我们进行的实验中，热源表示为一个浮力羽流，和冷却扩散器建模使用负浮力垂直射流。实验表明，系统的特性是由卷吸到羽流和负浮力射流。我们这些卷吸系数的卷吸过程的特点，并开发了一个理论模型的基础上分层模型的通风流量。模型预测与实验室实验进行了比较，并用于确定这些参数对冷却负荷，通风量和冷却扩散器的属性的依赖性。
This paper discusses the fluid dynamics of an underfloor air distribution (UFAD) ventilation system in which, in contrast to conventional air-conditioning systems, cool air is delivered from diffusers in the floor rather than from overhead vents. In order to produce more realistic models of UFAD systems, we extend previous work on a simplified system consisting of a single heat source at floor level and a single cooling diffuser, to the case of multiple cooling diffusers and a single heat source located at different heights above the floor. We carry out experiments in which the heat Source is represented as a buoyant plume, and the cooling diffusers are modelled using negatively buoyant vertical jets. The experiments show that the properties of the system are determined by the entrainment into the plumes and the negatively buoyant jets. We characterize these entrainment processes by entrainment coefficients, and develop a theoretical model based on layered models of ventilation flows. The model predictions are compared with the laboratory experiments, and used to determine the dependence of these parameters on the cooling load, the ventilation rate and the properties of the cooling diffusers.