Design of the Purdue Experimental Turbine Aerothermal Laboratory for Optical and Surface Aero-Thermal Measurements

Following three decades of research in short duration facilities, Purdue University has developed an alternative turbine facility in view of the modern technology in computational fluid mechanics, structural analysis, manufacturing, heating, control and electronics. The proposed turbine facility can perform both short transients and long duration tests, suited for precise heat flux, efficiency and optical measurement techniques to advance turbine aero-thermo-structural engineering. The facility has two different test sections, linear and annular, to service both fundamental and applied research. The linear test section is completely transparent for visible spectra, aimed at TRL 1 and 2. The annular test section was designed with optical access to perform proof of concepts as well as validation of turbine components at the relevant non-dimensional parameters in small engine cores, TRL 3 to 4. The large mass flow (28 kg/s) combined with a minimum hub radius to tip radius of 0.85 allows high spatial resolution. The Reynolds (Re) number extends from 60,000 to 3,000,000, based on the vane outlet flow with an axial chord of 0.06 m and a turning angle of 72 deg. The pressure ratio can be independently adjusted, allowing for testing from low subsonic to Mach 3.2. To ensure that the thermal boundary layer is fully developed the test duration can range from milliseconds to minutes. The manuscript provides a detailed description of the sequential design methodology from zero-dimensional to three-dimensional unsteady analysis as well as of the measurement techniques available in this turbine facility.