|Budget Amount *help
¥7,900,000 (Direct Cost : ¥7,900,000)
Fiscal Year 2000 : ¥1,500,000 (Direct Cost : ¥1,500,000)
Fiscal Year 1999 : ¥2,400,000 (Direct Cost : ¥2,400,000)
Fiscal Year 1998 : ¥4,000,000 (Direct Cost : ¥4,000,000)
Laser based flow measurements such as Laser Doppler Velocimetry and Particle Image Velocimetry have been applied for practical configuration and played an important role of technology development. Recently, two-dimensional PIV has already seen in much practical cases. There is, however, some difficulty in extending this to three-dimensional flows. The present study describes to approach to measure three-dimensional flow files, namely one is multiplayer approach and the other is a stereoscopic approach. Both of the systems have been developed and their feasibility has been discussed. The multi-layer PIV system which proposed in this study provides two-component velocity fields in multiple planer domain by controlling sequence of light emission and image acquisition timing, thus information of velocity fields into the depth direction can be obtained independently. The stereoscopic PIV system provides three-component velocity field in single planer domain by stereoscopic image recording
and recombination procedure of the three-component vector, and reliable velocity field can be obtained from three-dimensional flow. As both of the methods which described in this study are based on conventional PIV method, difficulties to extend into three-dimensional measurement devices have been resolved and it has become possible that applying the developed systems to practical flow fields. And discussion of feasibility of the conventional PIV system has enabled clarifying to discuss about the three-dimensional measurement devices. In the multi-layer PIV system, as high power pulsed laser diodes have been used as illumination, flexibility to control light emission timing has made decomposition of three-dimensional information possible. Moreover, both of compactness and remarkable cost reduction have been achieved. In the stereoscopic PIV system, original implementation of the system provides possibility of discussion about additional uncertainties by three-component recombination procedure. As a vortex behind a cylinder has been measured by multi-layer PIV, three-dimensional flow structure in two planer domain has been measured in small time lag regarded as simultaneous fluid dynamically. In addition, two-dimensional oblique jet has been measured by stereoscopic PIV and reliability of measured in-plane velocity and a limit of accuracy to measure fluctuation of the final-component velocity are clarified.