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Obayashi, Hironari; Tasaka, Yuji*; Kon, Seiji*; Takeda, Yasushi*
Flow Measurement and Instrumentation, 19(3-4), p.189 - 195, 2008/06
Times Cited Count：13 Percentile：50.68(Engineering, Mechanical)This paper proposes a new technique that enables the measurement of the velocity vector in multi-dimensions on a line of the flow field. A system to achieve this goal was developed based on ultrasonic velocity profiling by using multiple transducers. A two-dimensional system was constructed and successfully applied to an actual flow field for two-dimensional velocity vector measurements. To estimate the influence of existence of a wall, acoustic field under the developed system was calculated by solving two-dimensional wave equation and then the focal point of an ultrasonic beam was determined to optimize the system. The system was applied to measure two directional velocity components of a periodic velocity fluctuation in a wake of a cylinder as an example of unsteady flow. Temporal variation of velocity vector profiles well represent the velocity fluctuation, and vorticity distribution, which is obtained from the spatial distribution of velocity vector, well represents vertical motion in the wake.
Tasaka, Yuji*; Takeda, Yasushi*; Obayashi, Hironari; Yanagisawa, Takatoshi*
Choompa Techno, 18(6), p.70 - 74, 2006/11
Ultrasonic Velocity Profiler (UVP) enables us to obtain the velocity profiles in liquid metals. It is obvious that any optical method of flow measurement cannot be applied since all the liquid metals are opaque. This meant that non-invasive flow measurement was not possible until the ultrasonic measurement has been established. In this short review, we explain the various measurement relut given by UVP.
Obayashi, Hironari; Tasaka, Yuji*; Takeda, Yasushi*
Kashika Joho Gakkai-Shi, 26(103), p.252 - 257, 2006/10
Ultrasonic velocity profiler (UVP) has been established in fluid mechanics and fluid engineering applications of flow measurement. It is utmost importance to investigate flow structure and behavior of liquid metals when it is used in an active manner not only in heat transportation but also a flowing medium, as is the case for any kinds of situations of fluid flow is involved, and as such, fluid mechanics is applied. It is obvious that any optical method of flow measurement cannot be applied since all the liquid metals are opaque. This meant that non-invasive flow measurement was not possible until the ultrasonic measurement has been established. In the past studies, UVP has been applied to the flow measurement of liquid metal. In this paper, we show some examples which measured the liquid metal flow and introduce a new measurement system based on the UVP techniques.
