Session: 02-02 Ceramics and Composites II: Application

Paper Number: 103660

103660 - Life Cycle Analysis of Cmc Samples in a Stagnation-Point Reacting Flow at High Pressure 

A laboratory scale high-pressure flow reactor has been developed to study the interaction of a steam jet with various advanced ceramic and environmental barrier coating samples. Previous research studies were conducted at close to atmospheric pressure and have proposed an empirical relation for material recession. But none of them have been able to extract a pressure dependence factor with high fidelity. To address this deficiency, in the present study test conditions of steam at 1400 Celsius, pressures up to 5 atm, and velocities exceeding 200 m/s (positioned at 1 mm from the surface and at variable impinging angles) have been considered. These conditions mimic the local water molecule number density and velocity in actual gas turbine engine components, with test duration exceeding 24 hours. The initial life cycle data of Silicon Carbide (SiC) and Yb₂Si₂O₇ (YbDS) interactions with water vapor show very interesting physical and chemical mechanisms controlling the recession rates. Characterization with SEM, EBSD, and EDS [TL1] show the microstructural evolution, reaction depth and morphology. Complementary well-resolved computational fluid dynamic simulations have been performed to support the experimental setup and results, shedding new insight into the role of stagnation regions in the flow field where the flow residence times are the highest.

Presenting Author: Harsha K. Chelliah Univ Of Virginia

Presenting Author Biography: Harsha Chelliah is a professor in Mechanical and Aerospace engineering at the University of Virginia. He received his PhD in Mechanical and Aerospace Engineering from Princeton University in 1988. His research is focused on fundamental interactions between finite-rate kinetics and fluid flow using both experimental and modeling approaches. He has developed several unique high-pressure reactors to investigate fundamental issues related hypersonic and gas-turbine propulsions systems, including ceramic material synthesis and life-cycle analysis. He is a Fellow of the Combustion Institute, a Fellow of American Society of Mechanical Engineers, and an Associate Fellow of the American Institute of Aeronautics and Astronautics. He is also a Visiting Fellow of the Peterhouse College, Cambridge University, and the 2016 Thomas Jefferson Visiting Fellow at Downing College, Cambridge University. He is currently serving as a member of the editorial board of the Combustion Theory and Modeling Journal. While at UVa, he has held several visiting scholar positions and they include Cambridge University, University of Sydney, National Institute of Standards and Technology, and Naval Research Laboratory. More recently, he was the Program Director for Combustion and Fire Systems at the National Science Foundation for two years.

Authors:

Chinmay Nair University of Virginia
John Cooper University of Virginia
Chong Cha Rolls-Royce Corporation
Harsha K. Chelliah Univ Of Virginia