Affiliation:
1. School of Engineering and Physical Sciences (EECE Section), Heriot-Watt University, Riccarton, Edinburgh, UK
Abstract
A comparison of simulation and practical results for torque and power measurement have been undertaken for an impulse type of microelectromechanical systems microturbine. The microturbine module having a rotor diameter of just under 4 mm, an inlet channel that is 1 mm wide by 0.5 mm high, using an air drive has been extensively studied over the last few years. The simulation work has been undertaken using commercially available ANSYS and FEMLAB finite-element methods packages. From extensive simulation studies, the levitation of the rotor by using an appropriately shaped stepped base bearing plate on the stator surface was predicted by Flockhart in 1998 in her PhD thesis working under the direction of the principal author of the current paper. Only very recently has it been possible to carry out practical studies on the module to determine parameters such as, speed, torque, power, and especially levitation height. The practical results are in good agreement with the simulation results, bearing in mind that frictional effects were not accounted for, in the simulations. The feasibility of using the module as a microgenerator has been demonstrated by making use of commercially available minimagnets and a power of 1.2 mW was developed at 250 kPa input air pressure. At this value of input air pressure, a rotational speed of 30 000 r/min was obtained and a torque of 0.4 μNm could be produced.