Windage Heating in a Shrouded Rotor-Stator System.

Area of Science:

• Fluid dynamics
• Heat transfer
• Turbomachinery

Background:

• Windage heating is a critical factor in rotating machinery performance.
• Understanding temperature rise in rotor-stator systems is essential for thermal management.

Purpose of the Study:

• To experimentally and numerically study windage heating in a shrouded rotor-stator disk system with superimposed flow.
• To investigate the influence of flow parameters and gap ratio on temperature rise.
• To validate measurement techniques and computational fluid dynamics (CFD) simulations.

Main Methods:

• Development of a test rig for a 0.45m diameter disk rotating up to 12,000 rpm.
• Utilized infrared thermography for direct rotor surface temperature measurement.
• Employed Particle Image Velocimetry (PIV) for tangential velocity measurements.
• Performed CFD simulations for comparison with experimental data.

Main Results:

• Infrared thermography accurately measured adiabatic disk temperature.
• For low turbulence, gap ratio had minimal impact on radial temperature distribution.
• At higher turbulence, temperature rise became independent of gap ratio, dependent on Reynolds numbers.
• PIV confirmed swirl ratio significantly affects windage heating.

Conclusions:

• Windage heating is strongly influenced by rotational and throughflow conditions.
• Turbulence level is a key parameter determining the dependence on gap ratio.
• Swirl ratio plays a crucial role in the thermal behavior of the rotor-stator cavity.