Online

Nolan, Christopher Michael

Mechanical Engineering

2023

M.S.

Flexible thermal protection systems (FTPS) are being considered as they allow for atmospheric reentry of larger payloads. Current rigid aeroshells struggle to achieve this as they are limited by the shroud of the rocket being used. One promising material candidate for these flexible heat shields is a Hi-Nicalon silicon carbide (SiC) fabric. By utilizing the UVM 30 kW Inductively Coupled Plasma Facility, an array of experiments were performed to explore the chemical response to plasma in a variety of atmospheric conditions. The main goal of this thesis is to better understand gas surface interactions, mainly through two-photon laser-induced fluorescence (TALIF) and Raman scattering. These methods of probing the flow measure atomic reactant species density and molecular product species within the boundary layer respectively. Performing TALIF would be improving on the statistical distribution of catalytic rates previously measured at UVM. A Raman Scattering model was created to effectively extract temperature and density information from the experimental data. Over the course of these long scans, it needs to be assured that the chemical composition of the surface has reached a steady state. To assess the surface chemistry of a sample, an SEM and EDS interrogation were implemented to observe the change of surface chemistry over the course of 10 minutes of exposure.