Research Development of multi-dimensional combined measurement in heat and fluid flow by multi-layer imaging.

激光多谱勒测速和粒子图像测速等激光测流技术已经在实际工程中得到应用，并对技术发展起到了重要作用。最近，二维PIV已经在许多实际案例中得到了应用。然而，将这一点扩展到三维流动存在一些困难。本研究描述了一种测量三维流文件的方法，即多层方法和立体方法。这两个系统都已开发完成，并对其可行性进行了讨论。本文提出的多层PIV系统通过控制发光顺序和图像采集时序，在多平面域提供双分量速度场，从而可以独立获取深度方向的速度场信息。立体PIV系统通过记录…的立体图像，提供了单平面区域的三分量速度场更多的三分量矢量的复合过程，从三维流动中可以得到可靠的速度场。由于本研究中的两种方法都是基于传统的PIV方法，解决了扩展到三维测量设备中的困难，并使所开发的系统应用于实际流场成为可能。并对传统PIV系统的可行性进行了讨论，使得对三维测量设备的讨论变得更加清晰。在多层PIV系统中，由于使用了高功率脉冲激光二极管作为照明，灵活地控制发光定时使三维信息的分解成为可能。此外，还实现了紧凑性和显著的成本降低。在立体PIV系统中，系统的原始实现提供了通过三分量重组过程讨论附加不确定度的可能性。利用多层PIV测量了圆柱体后的旋涡，将小时滞视为同时流动动态测量了双平面区域内的三维流动结构。此外，还利用立体PIV对二维斜喷流进行了测量，阐明了面内速度测量的可靠性和测量最终部件速度波动的精度限度。较少

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 a … More nd 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. Less