Inlet Flow Characteristics During Rapid Maneuvers for an F/A-18A Aircraft

Steenken, William G. and Williams, John G. and Walsh, Kevin R. (1999) Inlet Flow Characteristics During Rapid Maneuvers for an F/A-18A Aircraft. Technical Report NASA/TM-1999-206587, Research Engineering, NASA Dryden Flight Research Center.

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Abstract

The F404-GE-400 engine powered F/A-18A High Alpha Research Vehicle (HARV) was used to examine the characteristics of inlet airflow during rapid aircraft maneuvers. A study of the degree of similarity between inlet data obtained during rapid aircraft maneuvers and inlet data obtained at steady aerodynamic attitudes was conducted at the maximum engine airflow of approximately 145 lbm/sec using a computer model that was generated from inlet data obtained during steady aerodynamic maneuvers. Results show that rapid-maneuver inlet recoveries agreed very well with the recoveries obtained at equivalent stabilized angle-of-attack conditions. The peak dynamic circumferential distortion values obtained during rapid maneuvers agreed within 0.01 units of distortion over the 10 - 38 degree angle of attack range with the values obtained during steady aerodynamic maneuvers while similar agreement was found for the peak dynamic radial distortion values up to 29 degrees angle-of-attack. Exceedences of the rapid-maneuver peak dynamic circumferential distortion values relative to the peak distortion model values at steady attitudes occurred only at low or negative angles of attack and were inconsequential from an engine-stability assessment point of view. The results of this study validate the current industry practice of testing at steady aerodynamic conditions to characterize inlet recovery and peak dynamic distortion levels.

EPrint Type:	NASA Technical Memorandum
Keywords:	Aircraft rapid maneuvers, F-18 aircraft, F/A-18A, High angle of attack, Inlet distortion, Inlet-engine compatibility
Subjects:	Aircraft/Project: F-18 HARV (01 - 09) Aeronautics: (07) Aircraft Propulsion And Power Aircraft/Project: F-18
ID Code:	99
Deposited On:	03 June 2004
Additional Information:	220 pages. W. G. Steenken and J. G. Williams, GE Aircraft Engines, Cincinnati, Ohio, and K. R. Walsh, Dryden Flight Research Center, Edwards, California. NASA Contract NAS3-26617.