The problems of gas turbine exhaust gas sampling by presently approved methods make an optical method attractive. Because of this, the Air Force has sponsored the development of laser. Raman for exhaust emissions measurement. Laser induced Raman and fluorescent measurements were made in the exhaust of a T53-L-13A gas turbine engine with a new field-portable instrument devised specifically for gas turbine exhaust emission measurements. The gas turbine exhaust was analyzed by conventional instruments for CO, CO2, NO, NOx total hydrocarbons, smoke, and temperature, and these data were used as a comparative standard for the evaluation of the laser Raman instrument. Results thus far indicate good to excellent correlations for CO2, O2, smoke, hydrocarbons, and temperature. NO detection was not sensitive enough, but the data analysis indicates that 100 ppm or less may be detectable with instrument improvements. Further NO sensitivity is possible with continued development of the method. CO analysis was not attempted, but it is expected that CO could be detected with further research. NO2 was not attempted because theoretical and experimental laboratory analysis indicated severe interferences with CO2. Temperature profiles from laser Raman were also compared with thermocouple data in the exhaust stream, and showed agreement within the radiation error of the thermocouples. With further development, laser Raman shows a good potential for an optical method of aircraft gas turbine emission analysis.
Performance and Emission Characteristics of a Diesel Engine Fueled by Biodiesel-Ethanol-Diesel Fuel Blends