Experimental study of the thermal separation in a vortex tube
Experimental study of the thermal separation in a vortex tube
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DOI：
10.1016/j.expthermflusci.2012.12.009
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发表时间：
2013-04
影响因子：
3.2
通讯作者：
Yunpeng Xue;M. Arjomandi;R. Kelso
中科院分区：
文献类型：
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作者：
Yunpeng Xue;M. Arjomandi;R. Kelso
涡流管是一种简单的机械装置，能够从单次喷射中产生分离的冷、热流体流，已被用于许多应用中，例如加热、冷却和混合物分离。为了解释它的工作原理，实验和数值研究已经进行，并提出了几种解释的温度分离。然而，由于涡流管中物理过程的复杂性，这些解释并不完全一致，至今尚未形成共识。本文对涡流管内的流动特性进行了实验研究，着重研究了管内的热分离和能量传递。通过对管内三维速度、湍流强度、温度和压力分布的观测，更好地了解了管内的流动结构。本文报道了进口附近的强制涡逐渐转变为热端的自由涡的过程。计算得到的涡流管内火用分布表明，中心流向外的动能转换有助于温度分离。实验结果表明，冷热流的形成与管道内沿着方向的旋涡转化有直接关系。
A vortex tube, a simple mechanical device capable of generating separated cold and hot fluid streams from a single injection, has been used in many applications, such as heating, cooling, and mixture separation. To explain its working principle, both experimental and numerical investigations have been undertaken and several explanations for the temperature separation in have been proposed. However, due to the complexity of the physical process in the vortex tube, these explanations do not agree with each other well and there has not been a consensus. This paper presents an experimental study of the flow properties in a vortex tube focusing on the thermal separation and energy transfer inside the tube. A better understanding of the flow structure inside the tube was achieved, based on the observed three-dimensional velocity, turbulence intensity, temperature and pressure distributions. The gradual transformation of a forced vortex near the inlet to a free vortex at the hot end is reported in this work. The calculated exergy distribution inside the vortex tube indicates that kinetic energy transformation outwards from the central flow contributes to the temperature separation. Experimental results found in this research show a direct relationship between the formation of hot and cold streams and the vortex transformation along the tube.