Research Objectives

alt textA Centrifugal Stage Aerodynamic Research (CSTAR) compressor has been designed by Rolls-Royce and installed at Purdue to study its efficacy after the final stage of an axial compressor. In its current configuration, the facility allows for the exploration of a wide design space and provides experimental data to validate computational design tools. This compressor operates at a design speed of 22,500 rpm and has been instrumented to give a detailed understanding of the compressor performance.


Current research with the CSTAR compressor is funded by Rolls-Royce.



Current work:
  • LDV flow characterization in a modern centrifugal compressor – W. Gooding
    • Development of LDV capability for the CSTAR facility for understanding the flow physics in a centrifugal compressor
    • Two custom made windows enable optical access over the impeller knee, impeller exit, vaneless space and diffuser inlet
    • Future studies using LDV include surge testing.

  • Additive Manufacturing for Centrifugal Compressor Diffuser Design – R. Adkins-Rieck
    • Investigations in stereolithography, selective laser sintering, and direct metal laser sintering for applications in gas turbine engine compressors
    • Utilizing additive manufacturing to enable rapid testing of different centrifugal compressor diffuser designs
    • Embedded instrumentation for measurements in conventionally immeasurable locations (e.g., hub and vane passage)




Specific Instrumentation Capabilities

Pressure taps along the shroud and rakes at the inducer, impeller exit, diffuser inlet and exit, and in the turn-to-axial duct provide information about how the pressure increases through the flow passage. Total temperature and total pressure rakes can give performance information about individual components as well as the entire stage. Removable diffuser cartridges can be further instrumented to study unsteady phenomena or impeller-diffuser interactions.

Laser Doppler Velocimetry
Windows over the impeller knee region and the vaneless-diffuser inlet region provide optical access. Data in these regions will enable further understanding into the complex flow aerodynamics and provide a unique data set to enhance computational models.

Capacitance Probes
Capacitance probes are used to monitor real-time hot running impeller tip clearances. This capability is instrumental for health monitoring to avoid any rubbing during high loading events. There also provide high-accuracy tip clearance data for the tip clearance effects investigation.

Instrumented Vane Cartridges
Diffuser inlet total pressure and total temperature rakes are mounted along the span of four diffuser vane using instrumented vane cartridges. This provides unique information at the diffuser inlet to calculate individual component performance data.



Theses
  1. Methel, C. J., 2016, "An Experimental Comparison of Diffuser Designs in a Centrifugal Compressor," MS Thesis, School of Aeronautics and Astronauts, Purdue University.
  2. Dolan, M.P., 2015, "Establishing Repeatable Operation of a Centrifugal Compressor Research Facility for Aerodynamic Investigations," MS Thesis, School of Mechanical Engineering, Purdue University.
  3. Heckaman, B.A., 2014, "Design of Optical Access for the Application of Laser Doppler Velocimetry in a Low Specific Speed Centrifugal Compressor," MS Thesis, School of Mechanical Engineering, Purdue University.
  4. Miller, K.R., 2012, "Design of a Centrifugal Compressor Research Facility for Low Specific Speed Applications," MS Thesis, School of Mechanical Engineering, Purdue University.



High-Speed Compressor Research Laboratory, Purdue University