Research development of fibrescope PIV system (an improvement of accuracy by controlling an illuminating duration of semiconductor laser)

The objective of the present work is to establish a vector field imaging system using a PIV technique with an optical fiberscope for applications of closed vessels such as a reactor, power plant, chemical plant, or combustor. A distribution of correlation coefficients employed to find particle displacements has inadequate peak of the correlation pattern by a fiberscope array itself in a coventional PIV technique, so that in the present study, the pattern of the fiberscope array was eliminated by subtracting an reference image pattern of the array provided byaveraging and the erroneous vectors could be reduced. Further the improvement of accuracy was achieved to obtain vectors using a particle streak tracking method. The optical fiberscope PIV with a high-powered pulse controllable laser diode system makes it possible to thoroughly investigate inside vessels and further, the physical compactness was achieved.