ABSTRACT
A numerical solution is given for the radiation intensity from a spherical cavity whose spatial temperature and emissivity are both arbitrary. This simplifies and clarifies previous research. A numerical example with large axial temperature gradient is given, and it is suggested that this analysis could help establish the spherical cavity as a radiation standard.
ABSTRACT
Nonintrusive systems for the measurement on test rigs of aeroengine exhaust emissions required for engine certification (CO, NO(x), total unburned hydrocarbon, and smoke), together with CO(2) and temperature have been developed. These results have been compared with current certified intrusive measurements on an engine test. A spectroscopic database and data-analysis software has been developed to enable Fourier-transform Infrared measurement of concentrations of molecular species. CO(2), CO, and NO data showed agreement with intrusive techniques of approximately ?30%. A narrow-band spectroscopic device was used to measure CO(2) (with deviations of less than ?10% from the intrusive measurement), whereas laser-induced incandescence was used to measure particles. Future improvements to allow for the commercial use of the nonintrusive systems have been identified and the methods are applicable to any measurement of combustion emissions.
