Development and Experimental Verification of Precision Miniature Ultra-High-Speed Axial Air Turbine
Journal
International Journal of Precision Engineering and Manufacturing
ISSN
22347593
Date Issued
2025
Author(s)
Abstract
The ultra-high-speed spindle system is used in various industrial and medical fields, such as printed circuit board drilling, micro machining, and dental handpiece. The ultra-high-speed turbine-spindle system, which is driven by compressed air, is advantageous over its electrical counterpart, such as self-cooling, light weight, and is free from electro-magneto interference. The turbine impeller, which transforms the pneumatic energy to mechanical energy, is the most essential component in the turbine-spindle system. In this research, a precision miniature axial turbine is developed leveraging its higher output power to mass ratio, higher torque output, low response time, and simpler airways when compared to the radial turbine. Starting with the conceptual design, detailed design is then iterated using computer aided design and computer aided manufacturing software tools. Specifically, manufacturability and cost are considered while the functionality and precision are retained. Theoretical model with Euler turbomachine equation is first used for preliminary analysis. The simplified model does not capture variations in blade profiles, interactions between nozzles and blades, or the complex losses arising from local geometries and vortex formation. Thus, computational fluid dynamics simulation is conducted for quantitative analysis and design refinement. It was found that the inlet and outlet angles play a key role in balancing torque and rotational speed. Using fewer stator nozzles increases the free rotational speed and boosts torque by raising the inlet velocity, whereas a greater number of nozzles enhances flow uniformity but reduces output power. To validate the performance of the proposed design, several prototypical miniature axial turbines are manufactured with different design parameters. The experimental results show that the realized miniature axial turbines attain > 100 krpm rotational speed for 2.0 Bar inlet pressure, a stall torque ~ 5 Nmm, with dimensions of only 20 mm in diameter and 50 mm in length.
Subjects
Computational fluid dynamics
High speed axial turbine
Miniature spindle
Precision manufacturing
Publisher
SpringerOpen
Type
journal article