A newly developed method for detecting a pierced position/angle by using a pre-signal in bubble measurement via a Single-Tip Optical-fiber Probe
The Optical Fiber Probe (OFP) has been widely applied for measurement of gas-liquid two phase flows. One of the authors already developed an S-TOP (Single-Tip Optical-fiber Probe with a wedge-shape tip), and reported its satisfactory performance of bubble/droplet measurements only by using the single tip. The purpose of this study is to improve the accuracy of the S-TOP in bubble measurements. To detect a touch position of the S-TOP on the bubble surface is very important. We propose a pre-signal threshold method. The pre-signal appears when the STOP tip is approaching to the bubble frontal-surface. It appears intensively and sharply, only when the tip touches the center region of the bubble, vertically. Utilizing this useful characteristic of the presignal, we can extract only the signals possessing particular conditions that the S-TOP almost perpendicularly pierces the near center region of a bubble. Firstly, the details of the pre-signal threshold method are described. Secondly, the effectiveness of the method is demonstrated empirically. This method surely increases the accuracy of the S-TOP measurement in bubble chord length and velocity. Finally, we discuss the uncertainty of the S-TOP measurement.
Single-Tip Optical-fiber Probe Bubble measurement Measurement accuracy Pre-signal
Yuki Mizushima Takayuki Saito
Graduate School of Engineering, Shizuoka University Graduate School of Science and technology, Shizuoka University
国际会议
The 7th International Symposium on Measurement Techniques for Multiphase Flows(第七届国际多相流测试技术会议)
天津
英文
233-240
2011-09-17（万方平台首次上网日期，不代表论文的发表时间）