Gas Turbine Engine Particle Emission Characterization

ABSTRACT: Under this feasibility study, we will investigate innovative methods for characterizing particulate emissions with a high degree of specificity to nonvolatile soot. Currently, no single instrument is available that can provide complete characterization of soot emissions. Instrumentation for reliable detection and characterization of nonvolatile particulate matter to obtain mass concentration, particle number concentrations, size distributions and specific surface area are proposed. Integration of the methods will be used to provide the missing information needed for complete PM characterization. Calibration means for the set up and validation of these measurements will also be investigated. Laser induced incandescence (LII) techniques calibrated with NIST traceable means will be used to measure soot volume fraction, primary particle size, and specific PM surface area. Condensation particle counters (CPC) will be used to obtain particle concentrations. These measurements will be combined with the LII measurements to obtain soot equivalent mean volume diameter. Particle mobility detection methods will be used to obtain particle size distributions with corrections for soot aggregate morphology using the fractal dimensions and corrected drag for these aggregate particles. The LII measurements of primary particle size and equivalent mean volume diameter of soot will be used to qualify the mobility size distribution measurements. BENEFIT: The present SBIR Phase I program will lead to a measurement system for characterizing soot volume fraction, mass concentration, primary particle size, aggregate size distribution and mean size, and number concentration. This development may be scaled down to provide subsets of the information as needed. We expect to also provide calibration means to ensure the reliability of these measurements. Results made available with these integrated diagnostics will provide a complete characterization of nonvolatile PM emissions from gas turbine engines and other combustion sources such as diesel engines, direct injection gasoline engines, and power plants. PM characterization instruments that can reliably measure black carbon (soot) PM are needed by jet engine manufactures to support their development efforts required in meeting the more stringent emissions standards that are in place and expected in the future. These instruments will also be necessary to enforce compliance with these regulations. It is anticipated that subsets of the proposed integrated instruments will be required for PM measurements in urban areas including the areas in the vicinity of busy airports. Other commercial applications will include atmospheric studies of PM concentrations and how these nonvolatile particulate affect climate.