Emissions variability of JT9D-7 turbofan engines
Carbon monoxide, nitrogen oxides, hydrocarbons, and smoke emissions from ten randomly selected in-service JT9D-7 aircraft engines were measured during their standard performance acceptance testing after overhaul, and the mean values and variabilities of the measured data corrected to EPA's Reference Day conditions were calculated. A thermodynamic computer model of the engine was developed to forecast the effects of small perturbations of turbomachinery efficiencies and flow areas on the combustion conditions at ground idle and takeoff, and small (approx. 1Vertical Bar3<) losses in high-pressure compressor efficiency were identified as the major factor. The overhauled engines showed slightly lower general performance standards at takeoff, compared with new ones, which is likely to cause significant differences in mean emission levels. Because of the significant in-service deterioration between overhauls, an additional margin for NO/sub x/ emissions, which may increase by 5-10Vertical Bar3<, must be allowed to meet the continuous compliance requirement for air quality in airport environments.
- Research Organization:
- U.K. Minist. Defence
- OSTI ID:
- 6750529
- Report Number(s):
- CONF-790634-
- Journal Information:
- Proc., Annu. Meet., Air Pollut. Control Assoc.; (United States), Vol. 79-54.2; Conference: 72. annual Air Pollution Control Association meeting, Cincinnati, OH, USA, 24 Jun 1979
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AIRCRAFT
AIR POLLUTION
EXHAUST GASES
ENGINES
PERFORMANCE
POLLUTION REGULATIONS
AIR POLLUTION CONTROL
COMPUTERIZED SIMULATION
SENSITIVITY ANALYSIS
THERMODYNAMICS
TURBOMACHINERY
CONTROL
FLUIDS
GASEOUS WASTES
GASES
MACHINERY
POLLUTION
POLLUTION CONTROL
REGULATIONS
SIMULATION
WASTES
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)