Uncertainty in High-Pressure Stator Performance Measurement in an Annular Cascade at Engine-Representative Reynolds and Mach

Abstract

The betterment of the turbine performance plays a prime role in all future transportation and energy production systems. Precise uncertainty quantification of experimental measurement of any performance differential is therefore essential for turbine development programs. In this paper, the uncertainty analysis of loss measurements in a high-pressure turbine vane are presented. Tests were performed on a stator geometry at engine representative conditions in a new annular turbine module called BRASTA (Big Rig for Annular Stationary Turbine Analysis) located within the Purdue Experimental Turbine Aerothermal Lab. The aerodynamic probes are described with emphasis on their calibration and uncertainty analysis, first considering single point measurement, followed by the spatial averaging implications. The change of operating conditions and flow blockage due to measurement probes are analyzed using CFD, and corrections are recommended on the measurement data. The test section and its characterization are presented, including calibration of the sonic valve. The sonic valve calibration is necessary to ensure a wide range of operation in Mach and Reynolds. Finally, the vane data are discussed, emphasizing their systematic and stochastic uncertainty.

Ultra-Compact Traverse System for Transonic Annular Cascade

“…For example, the Purdue Small Turbine Aerothermal Rotating Rig (Cuadrado et al, 2019) uses an electric linear actuator to turn a ring on which are mounted three independent radial traverse gears. The Purdue Big Rig for Aerothermal Stationary Turbine Analysis (Bhatnagar et al, 2022) may also broadly be classified as a rotating casing facility, even though only a small brass carriage moves circumferentially. The carriage is guided by a track and is powered by an industrial robotic arm.…”

Uncertainty quantification for aerodynamic pressure probes, using adaptive quasi-Monte Carlo

“…Case-specific error sources that can introduce additional systematic errors are not addressed. For pneumatic probes, sources that fall into the latter category are, velocity gradient [46] and unsteadiness induced errors [9], wall [47] and hub/shroud [48] proximity and probe blockage [49]. The impact of all the aforementioned error sources can be critical on the final measurement and might require a case-tailored study to find ways to quantify, and at best case correct these error.…”