Purdue small turbine aerothermal rotating rig (Starr)

The development of efficient small core turbines is critical as the aviation industry pushes to higher OPR engines, hybrid propulsion concepts, and multi-stream engines. In response to the small core advancement, a purpose-built facility is designed to address small core turbine challenges. This paper presents the design of a two-stage turbine module, to be integrated within the Purdue Experimental Turbine Aerothermal Lab facility. The rig is designed for continuous and transient operation, enabling precise efficiency and heat flux measurements. Key aspects of the design include the rotor dynamic evaluation and the overall system thermal response. These assessments were performed using numerical models at multiple operating conditions along the envisioned operational envelope. The turbine rig was specifically designed to ensure highly accurate efficiency measurements and detailed flow diagnostics including optical measurement techniques for performance assessment. The facility has auxiliary systems which can provide multiple gases including N2, CO2 or dry air, providing coolant and control fluids with a large variability of density and blowing ratios. The energy extracted from the turbine is absorbed by a direct drive (no gearbox) high speed AC electric motor, enabling engine representative transient operation.