Chemical Quick-Quench Probe for Aircraft Engine Emissions Measurements

The chemical composition of the exhaust streams of aircraft engines (augmented and non-augmented) and combustors are required for the determination of combustion efficiency and for understanding pollutant formation. Typically, extractive sampling is used to measure aircraft emissions; however, these measurements are biased by chemistry that can occur as the gas sample travels through the probe and sample line. The goal of this project is to develop a reliable probe for quenching chemistry in aircraft exhaust, thus minimizing the measurement errors caused by chemical conversion during sampling. Under Phase I, ARI and its Phase II subcontractor, CFDRC, performed a comparison of potential quick-quench probe designs using advanced chemical kinetic and computation fluid-dynamic models. A prototype probe, which combines the best aspects of existing aerodynamic-quench probes and dilution probes, was constructed and shown to have good aerodynamic performance. Under Phase II, the prototype will be further refined using model-based design and laboratory testing of sampling performance (using a flat-flame burner) and aerodynamic performance (using a blowdown facility). Two rounds of engine tests will also be performed at the UTSI jet engine test bed using a novel radio-labeling technique to quantitatively determine the sampling efficiency. At the finish of this project, an optimized chemical quick-quench probe will be delivered including hardware, mechanical drawings, operating manual, and performance data.