Design principles and measured performance of multistage radial flow microturbomachinery at low Reynolds numbers

This paper introduces and experimentally demonstrates the design concept of multistage microturbomachinery, which is fabricated using silicon microfabrication technology. The design process for multistage microscale turbomachinery based on meanline analysis is presented, along with computational fluid dynamics predictions of the key aerodynamic performance parameters required in this design process. This modeling was compared with a microturbine device with a 4 mm diameter rotor and 100 μm chord blades, based on microelectromechanical system technology, which was spun to 330,000 rpm and produced 0.38 W of mechanical power. Modeling suggests a turbine adiabatic efficiency of 35% and Re =266 at the maximum speed. The pressure distribution across the blade rows was measured and showed close agreement with the calculation results. Using the model, the microturbine is predicted to produce 3.2 W with an adiabatic efficiency of 63% at a rotor speed of 1.1 × 10⁶ rpm.