Supercritical Fuel Measurements

Abstract

Work was performed on stimulated scattering for fuel property measurements at high temperatures and high pressures. The performance of a two-stage double-pass amplifier was improved to achieve required pulse energies and pulse lengths. Frequency modulation methods were developed to achieve rapid and sensitive stimulated scattering measurements. Frequency domain methods were developed to measure the refractive index to support conversion of spectroscopic parameters to physical parameters. System modifications were performed to convert the static measurement cell to a flowing cell. Stimulated Rayleigh scattering measurements were performed in JP-8 jet fuel. Analysis of high-temperature / high-pressure data in hexane provides evidence of the presence of an instability zone in the supercritical regime. Single-shot stimulated scattering measurements were performed with the stimulated Rayleigh scattering technique.