DATE:                        Thursday, 4.20.23

TIME:                         4:00pm 

LOCATION:              31-270

SPEAKER:                Isha Gupta, Ph.D.

TOPIC:                       Environmental barrier coating to mitigate metal ignition in high pressure oxygen environments

ABSTRACT:

Oxygen-rich turbopumps are essential for emerging oxidizer-rich and full-flow staged combustion rocket engines. The turbine in an oxygen-rich turbopump subjects materials to high-pressure, high-temperature gaseous oxygen environments, amplifying the risk of metal fires which serve as catastrophic, single-point failure modes. One candidate approach for mitigating the risk of metal ignition, specifically through particle impact ignition, is to coat metallic components with inert ceramic environmental barrier coatings (EBCs); however, such coatings are susceptible to delamination under the rapid thermal transients upon engine startup and shutdown. Here, we investigate the delamination risk of a novel ductile phase-toughened composite EBC under a nominal flight cycle for a reusable boost-stage engine. The results show that cold shock at shutdown gives rise to the highest energy release rate for coating delamination, of order 100 J/m2, which will cause conventional monolithic ceramic coatings to delaminate. By contrast, we predict that the composite EBC of present interest resists transient-driven delamination due to crack bridging while protecting the underlying metal from particle impact ignition. Finally, the talk will highlight strategies to mitigate damage by tailoring the operating environment and coating design.

BIO:
Isha Gupta is a postdoctoral associate in the MIT Aerospace Materials and Structure Laboratory, working with Prof. Zachary Cordero in the Department of Aeronautics and Astronautics. Her research focuses on developing an environmental barrier coating to mitigate the risk of metal ignition in high-pressure oxygen environments of staged combustion rocket engines. Isha received her PhD in Mechanical Engineering from the University of Michigan under the guidance of Prof. Michael Thouless and Prof. James Barber. In her PhD thesis, she developed a novel approach for modeling the anomalous periodic oxidation behavior of zirconium alloys, which are widely used as fuel rod cladding material in pressurized water reactors. Isha’s research interest lies in developing environmental-barrier materials for next-generation energy, space launch, and aerospace technologies, where materials will be subject to extremely hostile operating conditions. Her work leverages multi-physics modeling of failure coupled with advanced material processing and damage characterization techniques to develop material design strategies for safe operation in extreme environments.