Local interfacial velocity measurement method using a four-sensor probe
Local interfacial velocity measurement method using a four-sensor probe
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DOI：
10.1016/j.ijheatmasstransfer.2013.08.064
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发表时间：
2013-12
影响因子：
5.2
通讯作者：
Xiuzhong Shen;H. Nakamura
中科院分区：
文献类型：
--
作者：
Xiuzhong Shen;H. Nakamura
本文提出了用四传感器探头测量多维两相流瞬时局部界面速度矢量和时均局部界面浓度的理论基础。该测量方法是基于大气泡假设，即局部地将接近气泡的前后界面视为两个切平面。新推导的方法提供了一个显式的表达的瞬时局部界面速度矢量使用四传感器探头。推导出的时间平均局部界面面积浓度的方法与Kataoka等人（1986）[1]提出的方法形式相同。将该方法应用于内径为200 mm的垂直管内两相流的实际测量。在轴向方向上的空隙率和界面速度分量的测量进行了检查，对空隙率测量使用差压计和表观气体速度测量使用气体流量计，分别。实验测得的径向速度分量和周向速度分量中的界面速度分量均接近于零，这与垂直圆管中不存在具有一定水平速度分量的稳定气泡流的事实相一致。测得的界面面积浓度显示合理的径向分布在管道中。实验结果表明，该方法能够合理地测量多维两相流的界面速度矢量和界面浓度。
This paper presents a theoretical foundation of the measurement methods for the instantaneous local interfacial velocity vector and the time-averaged local interfacial area concentration using a four-sensor probe for multi-dimensional two-phase flow measurements. The measurement method is derived based on a large bubble assumption that locally views the front and rear interfaces of an approaching bubble as two tangent planes. The newly-derived method provides an explicit expression for the instantaneous local interfacial velocity vector using a four-sensor probe. The derived method for the time-averaged local interfacial area concentration was found to be in the same form as that proposed by Kataoka et al. (1986) [1]. The derived method was applied to the practical two-phase flow measurements in a vertical pipe with an inner diameter of 200 mm. The measured void fraction and interfacial velocity component in the axial direction were checked against the void fraction measurement using differential pressure gages and the superficial gas velocity measurement using gas flow meters, respectively. The measured interfacial velocity components in the radial and circumferential velocity components were found to be close to zero, which is in accordance with the fact that no stable flow of bubbles with certain horizontal velocity component exists in a vertical circular pipe. The measured interfacial area concentrations showed reasonable radial distributions in the pipe. The good agreements in the practical measurements suggest that the newly-derived method can reasonably measure interfacial velocity vector and interfacial area concentration in multi-dimensional two-phase flows.