Molecular sensors in microturbine measurement

Microturbines have been studied for use in micro size engines as a fuel cell for power generation. These micro engines are designed to offer power output around a couple watts with a very small, compact size. However, there are a lot of difficulties for these small size turbines such as high friction, unstable rotor movement etc, that make the microturbines break down much earlier in their life cycle. These problems needed to be solved in order to improve the efficiency of microturbines. However, it is difficult to install micro sensors in the microturbine device for measurement. A novel technique of molecular sensor, known as pressure-sensitive paint and temperature-sensitive paint (PSP/TSP) has been developed to obtain the pressure and temperature field inside the microturbine device. The PSP sensors used in the experiments are PtTFPP/PolyTMSP for time-averaged pressure measurement, and PtTFPP/TMSP for phase-averaged pressure measurement. The TSP sensor of Ru(phen)3+/Polyacrylic is used for the temperature measurement. The PSP/TSP sensor is coated on glass slides and the glass slide is used as cover glass for the microturbine device. Pressure and temperature distributions inside the microturbine device have been successfully obtained with PSP and TSP sensors. The rotation speed for the microturbine varies from 1300 to 4000 rpm for different flow rates from 5 to 15 L/min for the time-averaged experiments. Phase-averaged results have been obtained with a laser triggering system at a rotation speed of 1400 rpm and volume flow rate of 17 L/min. The temperature map inside the microturbine has been acquired with the TSP sensor with a rotation speed from 1300 to 4000 rpm and flow rates from 5 to 15 L/min. The PSP/TSP sensor has been demonstrated with the feasibility of measuring the pressure and temperature field inside the microturbine device with high spatial resolution, both in time-averaged and phase-averaged measurements.