An experimental study of an ultra-micro scale gas "Turbine"

This paper studies the performance of an ultra-micro scale gas "turbine" through an experimental investigation, through a series of transient and steady state tests. The investigation is carried out on a 20 mm (rotor diameter) radial turbine, manufactured via 3D printing from Ti-64, and it is the first of its kind at this scale. The transient runs consist of acceleration and deceleration tests, which are then used to calculate the mechanical torque and power curves. The steady state runs are also used to compute power curves, along with various non-dimensional performance plots. A maximum mechanical torque and power of 2.64 Nmm and 15 W were attained at a rotational speed of 44,000 and 60,000 rpm, from the transient tests. From the steady state tests, a maximum electrical and turbine power of 4 and 15 W were attained at a rotational speed of 57,000 and 69,000 rpm. Also, a thermal cyclic efficiency of 18.6% was attained, and therefore the study has successfully investigated the performance of the turbine.