Reevaluation of Nitric Oxide Concentration in Exhaust of Jet Engines and Combustors
Abstract
Several measurements of nitric oxide (NO) concentrations in the exhaust of jet engines and combustors by probe sampling and ultraviolet (UV) resonance absorption have been reported. Generally, the optically determined concentrations have exceeded the probe determined values appreciably. The theoretical basis for the determination of the NO concentration from absorption measurements has recently been reexamined, and the values previously reported were redetermined. Upon reexamination, the parameter a (the ratio of collisional plus natural half-width to the Doppler half-width) was found to obey the relationship a = C P/T sub 0 to the 1.5 power where P is the pressure in atmospheres, T is the temperature in K, and C is a constant. The value of C was found to be 3.81 (+ or - .40) x 10,000 k to the 1.5 power/atm. The major conclusion of previous studies remains unchanged, namely, that optically determined NO concentrations may be a factor of 5 larger than probe determined values or may be the same, depending on the combustion gas flow conditions and/ or probe design. However, certain optically determined NO concentrations varied by as much as 46 percent from previously reported values because of alternations made to the theory and parameters.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1981
- Accession Number
- ADA103118
Entities
People
- H. S. Lowry Iii
- J. D. Few
Organizations
- Arnold Engineering Development Complex