"Development of Three-dimensional Particle Imaging Ther metry and Velocimetry for Analyzing a Complex Thermal Flow Field"

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A spatial simultaneous measurement method for temperature and velocity of a complex thermal flow has been developed. The new method was based on the liquid crystal thermometry, the digital color image processing technique and the three-dimensional particle imaging velocimetry by the stereo photogramtry. This method was called the three-dimensional Particle Imaging Thermometry and Velocimetry (3D-PITV) . The conclusions of this research work can be summarized as follows.(1) The bragg-type scattering phenomenon of the micro-capsulated liquid crystal has been proved quantitatively through a digital color image processing.(2) The optical characteristics of color to temperature of the micro-capsulated liquid crystal is identified quantitatively by the neural network.(3) The response time of the liquid crystal particle itself has been calculated through a numerical simulation and its availability has been verfied with the possibility of the micro capsulated liquid crystal particle being used as a temperature sensor for the measurement of thermal turbulent flow.(4) The hardware system of the 3D-PITV which consists of a monochrome CCD camera, a three planes of color CCD camera, optical video disk recorders, a color image processor and a micro-computer has been constructed.(5) After confirming no effects of the bragg-type scattering, the system has been applied to measure a vertical buoyant jet. The radial distribution of vertical velocity and mean temperature show similarity with other researcher's results by one point measurements in self-preservation region of the jet.