Session: 33-02 Experiments of particle deposition in engine components

Paper Number: 124173

124173 - Direct and Refined Characterization of Rebound for Irregularly Shaped, High-Speed Particles Incident on Aerospace Grade Titanium 

Erosion caused by debris ingestion has been an issue that has plagued turbomachinery for decades. The complexity surrounding the ingested particles and operating machinery make this a problem that is not easily solved. Two parameters often used to characterize particle-surface interactions in turbomachinery are the coefficient of restitution (COR) and rebounding angle. A fully time-resolved two-dimensional Particle Tracking Velocimetry (2DPTV) system is employed on a high-speed free jet rig to study particle-surface interactions for 150𝜇𝑚−250𝜇𝑚 crushed quartz incident on Grade 4 (Commercial) Titanium. Particle speeds range between 60𝑚/𝑠 and 120𝑚/𝑠 and nominal incidence angles of 30° and 90° were studied. In this work, a novel approach that couples the study of both the particle and particle-surface interactions is discussed. Specifically, a current model in the literature is improved upon to include particle shape effects in the normal coefficient of restitution. It is shown that this improved analytical model also accounts for the spread or variation in results observed in the normal coefficient of restitution data. In addition to a full description of the experimental procedure and model development, a source of random uncertainty, unreported in previous literature, is fully characterized for both velocity and angle measurements. Results from this work strongly suggest that irregular particle shape is the driving mechanism behind spreads observed in the coefficient of restitution and rebounding angle.

Presenting Author: Brandon Weindorf Virginia Tech

Presenting Author Biography: I am a third-year Ph.D. student studying aerospace engineering at Virginia Tech. My research focuses on the underlying physics that govern the erosion process in turbo-machinery. Prior to pursing the Ph.D., I earned a Bachelor's of Science in Mechanical Engineering and a Bachelor's of Science in Physics from Messiah University in Pennsylvania, USA.

Authors:

Brandon Weindorf Virginia Tech
Alix Ehlers Virginia Tech
Todd Lowe Virginia Tech
Wing Ng Virginia Tech
Mark Caddick Virginia Tech
Jim Loebig Rolls-Royce
Matthew Morrison Virginia Tech