Session: 33-01 Deposition, erosion and fouling in gas turbine engines

Paper Number: 154066

Particle/blade Impact Study of Near-Transonic Compressor in Engine Test 

Compressor blade/particle interactions and erosion are studied for a Rolls-Royce M250-C20 turboshaft engine using computational and experimental approaches. Gas turbines, when subjected to sand- or dust-laden inlet conditions, often experience decreases in power production and efficiency, accelerated need for maintenance, and higher risk of failure.  Although efforts have been ongoing to solve this engine safety and durability problem, a deficit exists in the basic understanding of blade/particle interactions from the perspective of full-scale engine tests.  The Virginia Tech Advanced Propulsion and Power Laboratory is engaged in a multidisciplinary project with the US Navy, Pratt & Whitney, and Rolls-Royce to investigate this topic.

As part of this program, a novel method has been developed to study particle/surface impacts inside the compressor of a full gas turbine engine.  By applying machinist’s layout fluid to the compressor of a Rolls-Royce M250-C20 turboshaft prior to sand ingestion, useful insights can be gained into the mechanics of cold-section degradation.  Dust ingestion at the desired engine operating point results in preferential removal of the layout fluid coating at locations where particle impacts occur most heavily, providing a rich spatially resolved visualization of particle impact intensities across stages and on both rotating and non-rotating components.  In separate tests, particles of varying size and material were ingested at high engine power under nearly equal conditions, yielding interesting results.  The pressure side of the first stage rotor blades showed an especially unique removal pattern which exhibited high circumferential uniformity among blades.

Understanding the experimental observations requires supplemental findings from computational studies. Computational fluid dynamics (CFD) simulations for the first stage of the axial compressor have been developed. Within these simulations, the Bons coefficient of restitution (CoR) model and the Oka model for blade erosion have been implemented. The test conditions from the Virginia Tech test cell were simulated for quartz particles of sizes matching the experiments. From these computations, the erosion patterns at the first rotor were quantified and compared to the removal of the layout fluid. The leading edge and tip of the rotor blade shows the highest erosion.

The manuscript will show synthesis of wear patterns from the experiments and computations to identify underlying dominant mechanisms and expose opportunities for fundamental modeling research. Furthermore, the experimental approaches will highlight how qualitative indicators for both deposition and erosion in a real engine can provide valuable insights without requiring costly degradation to engine performance or lengthy engine test campaigns.  The results can guide researchers toward reduced cost testing which maximize learning for the complicated problem of gas turbine engine particle ingestion.  The findings of this research effort will also enable better understanding of the complex interactions between particles and compressor components and will aid advancements in the accuracy of particle ingestion models, ultimately supporting improvements to safety, durability, and flight readiness of aircraft gas turbines.

Presenting Author: Boone Estes Virginia Tech Advanced Propulsion and Power Lab

Presenting Author Biography: Leonard (Boone) Estes is a 3rd year Mechanical Engineering PhD student at Virginia Tech advised by Dr. Wing Ng and Dr. Todd Lowe.  His research focuses on particle ingestion in aircraft gas turbines, leveraging development of novel instrumentation and test methodology to study the effects of particle properties on overall engine degradation using full-scale engine tests.

Authors:

Boone Estes Virginia Tech Advanced Propulsion and Power Lab
Paige Brockway Virginia Tech Transport Phenomena Lab
Leonardo Olivera Virginia Tech Advanced Propulsion and Power Lab
David Bunin Virginia Tech Petrology Lab
Rui Qiao Virginia Tech Transport Phenomena Lab
Wing Ng Virginia Tech Advanced Propulsion and Power Lab
Mark Caddick Virginia Tech Petrology Lab
Changmin Son Virginia Tech Advanced Propulsion and Power Lab
Todd Lowe Virginia Tech Advanced Propulsion and Power Lab
Gwibo Byun Virginia Tech Advanced Propulsion and Power Lab
Rory Clarkson Rolls-Royce
Jessica Cummings Rolls-Royce
Chong Cha Rolls-Royce
Jim Loebig Rolls-Royce
Charlie Haldeman Pratt & Whitney
Andy Consiglio Pratt & Whitney