타이틀 |
ESTIMATING ENGINE AIRFLOW IN GAS-TURBINE POWERED AIRCRAFT WITH CLEAN AND DISTORTED INLET FLOWS |
저자 |
J. G. Williams, W. G. Steenken and A. J. Yuhas |
Keyword |
Airflow correlation techniques; Airflow errors; Distorted inlet airflow; Engine airflow; GE 404 engine airflow |
URL |
http://www.dfrc.nasa.gov/DTRS/1996/PDF/H-2127.pdf |
보고서번호 |
NASA-CR-198052 |
발행년도 |
1996 |
출처 |
NASA Dryden Flight Research Center |
ABSTRACT |
The F404-GE-400 powered F/A-18A High Alpha Research Vehicle (HARV) was used to examine the impact of inlet-generated total-pressure distortion on estimating levels of engine airflow. Five airflow estimation methods were studied. The Reference Method was a fan corrected airflow to fan corrected speed calibration from an uninstalled engine test. In-flight airflow estimation methods utilized the average, or individual, inlet duct static- to total-pressure ratios, and the average fan-discharge static-pressure to average inlet total-pressure ratio. Correlations were established at low distortion conditions for each method relative to the Reference Method. A range of distorted inlet flow conditions were obtained from ?0 deg to +60 deg angle of attack and ? deg to +11 deg angle of sideslip. The individual inlet duct pressure ratio correlation resulted in a 2.3 percent airflow spread for all distorted flow levels with a bias error of ?.7 percent. The fan discharge pressure ratio correlation gave results with a 0.6 percent airflow spread with essentially no systematic error. Inlet-generated total-pressure distortion and turbulence had no significant impact on the F404-GE-400 engine airflow pumping. Therefore, a speed-flow relationship may provide the best airflow estimate for a specific engine under all flight conditions.
|