Abstract: Optical fiber sensor,as a new technique in the field of fiber optics,has received more and more attention in the measurement of local parameters in two-phase flow.The mathematical principle of the local instantaneous bubble velocity vector measurement using four-sensor probe was deduced by assuming a plane of symmetry of bubbles normal to the motion,and a new mathematical model was presented.An investigation was conducted for obtaining bubble velocity vector in two-phase flow by using a self-made four-sensor optical fiber probe.By comparing the superficial gas velocity obtained from the new probe method with that measured by flow meter,it was found that average deviation was about 9%,indicating a relatively high metrical precision of the new probe method.A further study indicated that local void fraction and interfacial area concentration(IAC)showed a wall peak or a core peak distribution in the radial direction under different flow conditions.

Key words: fiber optics, four-sensor optical fiber probe, bubble velocity vector, two-phase flow

摘要： 光纤传感器作为纤维光学领域中的新技术,在两相流动局部参数测量中得到了越来越广泛的应用。在假设气泡对称面垂直于气泡运动方向的基础上,对四传感器探针测量局部瞬时气泡速度的数学原理进行了详细推导,给出了新的计算气泡速度矢量的方法和模型,并运用自制的四传感器光纤探针,对气液两相流动中的气泡运动速度和方向进行了测量。实验中通过探针方法测得气相流速相对于流量计测量值的平均偏差为9%,表明新的探针测量方法精度较高,能够用于两相流中气泡速度矢量测量。进一步的实验研究表明,不同流动条件下,局部空泡份额及界面面积浓度(IAC)沿通道径向呈“壁峰型”或“核峰型”的分布规律。

关键词: 纤维光学, 四传感器光纤探针, 气泡速度矢量, 两相流