Experimental verification of the feasibility of a 100 W class micro-scale gas turbine at an impeller diameter of 10 mm

The feasibility of a 100 W class micro-scale gas turbine with a centrifugal impeller of 10 mm diameter has been studied by experimentally verifying the four major component performance requirements found from cycle analysis. The rotor is required to rotate at 870 000 rpm to generate the compressor pressure ratio 3, and it has successfully been achieved by using hydroinertia gas bearings. A compressor efficiency higher than that required by the target cycle has been measured. After correcting the effect of the heat leakage, approximately 65% of the compressor adiabatic efficiency is estimated to be achievable. The combustor has achieved stable self-sustained combustion at a combustion efficiency higher than 99.9%. The heat conduction analysis based on measured data showed that it is possible to keep the compressor below 170 °C when the turbine inlet temperature is 1050 °C. All four requirements are proven to be achievable, and hence, the feasibility of the micro-scale gas turbine at an impeller of 10 mm diameter has successfully been proven at component level.