A nozzle boundary-layer control systemis under consideration for application in high-pressure rockets tomitigate the erosion rates of a graphite nozzle. The current design contains multiple center-perforated solid grains of fuel-rich materials consisting of succinic acid and polyvinyl acetate. This combination of the fuel-rich grains was selected due to high carbon and hydrogen contents along with relatively low evaporation temperature for generating fuel-rich gases. The characterization of the pyrolysis behavior of fuel-rich grains is a requirement for any subsequent quantitative analysis pertaining to the effect of the nozzle boundary-layer control system on graphite rocket nozzle erosion rates. Two separate experiments were conducted: 1) to determine the regression rate of solid fuel-rich grains under controlled heat flux or temperature conditions, and 2) to characterize its chemical decomposition and/or evaporation behavior. An empirical correlation between heat flux and surface regression rate of fuel-rich grains was developed. From Fourier transform infrared spectroscopy measurements, the fuel-rich grains were found to melt and evaporate at temperatures up to 773 K. These results have been used in parallel study nozzle throat erosion processes using computational simulation.
All Science Journal Classification (ASJC) codes
- Aerospace Engineering
- Fuel Technology
- Mechanical Engineering
- Space and Planetary Science