Development of temperature sensitive particles for three-dimensional measurement of velocity and temperature

Presently, a temperature sensitive particle has been developed which enables us the three-dimensional simultaneous measurement of velocity and temperature in a fluid flow. As we are already made it possible to measure the three-dimensional velocity field with the aid of the three-dimensional particle tracking velocimetry (3-D PTV), the clue for the simultaneous measurement of three-dimensional velocity and temperature is how to let the tracer particles have the temperature sensitivity. It has been well known that the laser-induced fluorescence (LIF) is a very useful technique for the temperature measurement, but it has been used only for the two-dimensional measurement as the fluorescent dye has been used as a solution. So we have introduced the, solution of the fluorescent dye into the membrane of the microcapsule to let only the tracer particles themselves have the temperature sensitivity and made the three-dimensional temperature measurement possible. In this study, the manufacturing process of this temperature sensitive particle has been demonstrated and the brightness of the luminescence at each temperature has been measured to obtain a calibration curve for the temperature measurement by this particle. The effectiveness of the present particle for the temperature measurement has also been shown and the suggestions for the future studies has been demonstrated.