Session: 05-11 Turbine Facility Sensors & Diagnostics

Paper Number: 129316

129316 - The Purdue High-Speed Small Core Turbine Facility 

Short duration facilities, with testing time of the order of milliseconds to seconds, offer cost-effective solutions to achieve engine-relevant pressure and temperature ratios, in contrast to the continuously running rigs used in the industry. Alas, the short duration facilities require sufficiently fast instrumentation and high level of heat loss needs to be accounted for efficiency calculation. The Purdue Small Turbine Aerothermal Rotating Rig (STARR) was developed to test real engine hardware for small core turbine applications. The STARR facility is a small-core two-stage high-speed rotating test turbine running at engine representative Reynolds and Mach number which is capable of fast transients and steady condition of up to 6 hours with the enhanced pressure vessels in development. The facility is purposely built to test advancements in critical technologies for clean aviation, pushing towards higher OPR engines, hybrid propulsion and multi-stream engines. The facility is designed to be modular allowing faster turnaround times for new test articles. The paper presents the design, control and operation of the facility. Efficiency measurement in engine-representative test rigs is a challenging prospect which compounds due to the narrow uncertainty band required, ideally less than 0.5% uncertainty, to detect the incremental improvements achieved by turbine designers. For a small core turbine, accurately quantifying the tip clearance is also critical to assess relative change of performance. To that end, the instrumentation used for efficiency measurement and resolving unsteady flow phenomenon is presented.  The tip clearances are measured at different circumferential locations around the annulus of each stage, giving the circumferential variation of tip clearance and also aids in identification of the blade row signature throughout the operational map. The inlet characterization and commissioning of the test section is also presented. Uncertainty is quantified on efficiency measurement through a comprehensive framework that includes both precision and absolute level of uncertainty. The uncertainty is propagated from the individual sensor to the final efficiency calculation. The impact of heat flux and thermal transients is assessed[DR1]  using casing temperature measurements.  The challenges faced in the operation of such a facility are highlighted along with the steps proposed to mitigate them. 

 

Presenting Author: Lakshya Bhatnagar Purdue University

Presenting Author Biography: Lakshya Bhatnagar is a Research Scientist at Purdue University. He obtained his PhD in 2022 at Purdue University, focusing on data analytics and uncertainty quantification for turbine efficiency measurement. His work focuses on developing improved sensors and instrumentation for aerothermal measurements and utilizing data for improved modelling of turbine systems.

Authors:

Lakshya Bhatnagar Purdue University
Antonio Castillo Sauca Purdue University
Diego Sanchez De La Rosa Purdue University
Guillermo Paniagua Purdue University
Eugene Clemens Rolls-Royce Corporation
Matthew Bloxham Rolls-Royce Corporation