Dissertation Defense: Informing Physics-Based Particle Deposition Models Using Novel Experimental Techniques to Evaluate Particle-Surface Interactions

Committee Members

• Dr. Jeffrey Bons, Chair (Aeronautical and Astronautical Engineering)
• Dr. Mohammad Samimy (Aeronautical and Astronautical Engineering)
• Dr. Randall Mathison (Aeronautical and Astronautical Engineering)

Abstract
The increasing use of gas turbine engines in regions with high concentrations of particulate, along with the drive toward higher operating temperatures for efficiency, has led to increased problems associated with particle deposition. In order to make more informed decisions about component design and to predict life expectancy of components, a generalized physics-based model pf particle-surface interaction with deposition prediction is required. This work aims to inform existing physics-based models through the use of novel experimental and analysis techniques for measurement of particle coefficient of restitution data. This data, obtained for 20 different particle-temperature combinations and including information for more than 8.35 million individual rebounds, is used to identify areas in which existing models can be improved. Modifications suggested for a particular model include a velocity-dependent particle yield strength that accounts for strain hardening and strain rate effects and randomized rebound predictions to obtain data spread that matches that of experimental data. The modified model, with vastly improved predictive capabilities, is then used to determine temperature-dependent mechanical properties for several different particle compositions. The improvement in the model physics and the determination of thermally- and compositionally-dependent mechanical properties represents a significant advancement in deposition modeling and provides the foundation for further model improvement in the future.