Harvey V. Lilenfeld

Particulate sizing and emission indices for a jet engine exhaust sampled at cruise

Particle size and emission indices measurements for jet engines, primarily the Rolls Royce RB211 engines on a NASA 757 aircraft are reported. These data were used to estimate the fraction of fuel sulfur that was converted to particulates. These measurements were made in-situ with the sampling aircraft several kilometers behind the source. Some complimentary ground measurements on the same source aircraft and engines are also reported. Significant differences are seen between the ground observations and the in-situ observations, indicating that plume processes are changing the aerosols characteristics.

Methodology for Particle Characterization in the Exhaust Flows of Gas Turbine Engines

The University of Missouri-Rolla (UMR) has developed, constructed, and employed a trailer-housed mobile aerosol sampling system (MASS) for the physical characterization of particles extracted from the exhaust flows of gasturbine engines. The MASS has been designed for a range of sampling conditions typically encountered at exit planes of combustors, angular sector rigs, flame tubes, and actual engines. To date measurements have been conducted in test cells, altitude chambers, on the wing (on the ground), and in flight. Reaching beyond the historically used but limited concept of smoke number, the MASS relies on differential mobility analysis, laser particle sizing, transmission electron microscopy, and molecular absorption spectroscopy to measure directly particle number concentration and size distribution (0.01 to <25 μm), water mixing ratio, particle morphology, and carbon dioxide (CO2), Combined with key combustor/engine operating conditions and fuel properties the MASS provides a series of derived parameters including mean particle diameter and number-, surface-, and mass-based emission indices, which are important parameters for the performance characterization and environmental assessment of gas turbine engines. In this article we describe the technical details of the UMR MASS, discuss data reduction and experimental uncertainties, and show some example data sets.

Atomic iodine(2P1/2) deactivation by iodine chloride (ICl) and molecular chlorine

Mesure des vitesses de desexcitation dans un appareil a ecoulement rapide: elles sont plus lentes avec Cl 2