Investigation of the Rupture Initiation and Mechanical Performance of Alumina Port Covers for Integrated Rocket Ramjet Systems

Author

Haley R. Goldston, University of Tennessee Space InstituteFollow

Date of Award

12-2021

Degree Type

Thesis

Degree Name

Master of Science

Major

Aerospace Engineering

Major Professor

John D. Schmisseur

Committee Members

Trevor M. Moeller, Phillip A. Kreth, Mark T. Gragston

Abstract

Hypersonic flight is widely considered essential to ensure a competitive defensive capability in the United States. In hypersonic air breathing propulsion, cruise vehicles are a priority research and development area given the ease to which they can be implemented with existing DoD infrastructure. Advancements in ramjet engine systems, including integrated rocket ramjets, play a considerable role in military and space access hypersonic vehicle designs. By design, ramjets cannot produce static thrust. They first need to be brought to operational speeds with the help of a rocket booster. An integrated rocket ramjet (IRR) combines the booster phase and the ramjet phase in one single propulsion chain, further enhancing the systems efficiency. The key factor in IRR flight success is the separation of these two phases achieved by the use of a port cover, which will be discussed in detail throughout this paper.

In support of the continued maturation of IRR technologies, the University of Tennessee Space Institute has collaborated with Air Force Research Labs, NASA Langley Research Center and the Defense Science and Technology Labs to investigate the viability of alumina port covers through a numerical and experimental campaign. Verified by finite element stress analysis, UTSI tested alumina port covers with a 45-degree dome angle and 6mm thickness that were fabricated and purchased from three external vendors. Flight conditions were simulated using a high-pressure chamber and a mechanical fracturing mechanism was used to initiate fracture on the pressurized port covers.

High-speed cameras and retroreflective shadowgraphy techniques were used to obtain initial crack propagation patterns and average fragment velocity. The fragments were collected post-rupture and measured to estimate an average fragment size. It is imperative the fragment size is small enough to ensure no damage will occur to the internal structure of the flight vehicle during exit. Ultimately, the goal of this research is to determine if alumina port covers are suitable for vehicle use.

Recommended Citation

Goldston, Haley R., "Investigation of the Rupture Initiation and Mechanical Performance of Alumina Port Covers for Integrated Rocket Ramjet Systems. " Master's Thesis, University of Tennessee, 2021.
https://trace.tennessee.edu/utk_gradthes/6291