Design, fabrication, and testing of a MEMS microturbine

This paper describes the design, fabrication, and testing of a microturbine developed at Seoul National University Here, the term “microturbine” refers to a radial turbine with a diameter on the order of a centimeter Such devices can be used to transmit power for various systems The turbine is designed using a commercial CFD code, and it has a design flow coefficient of 0 238 and work coefficient of 0 542 It has 31 stator blades and 24 totor blades A hydrodynamic journal bearing and hydrostatic thrust bearings counteract radial and axial forces on the rotor The test turbine consists of a stack of five wafers and is fabricated by MEMS technology, using photolithography, DRIE, and bonding processes The first, second, fourth, and fifth layers contain plumbing, and hydrostatic axial thrust bearings for the turbine The third wafer contains the turbine’s stator, rotor, and hydrodynamic journal bearings Furthermore, a turbine test facility containing a flow control system and instrumentation has been designed and constructed In performance tests, a maximum rotation speed of 11,400 rpm and flow rate of 16,000 seem have been achieved