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Flight-determined, subsonic, lateral-directional stability and control derivatives of the thrust-vectoring f-18 high angle of attack research vehicle (harv), and comparisons to the basic f-18 and predicted derivatives
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Wang Sr., Kon-Sheng Charles Iliff, Kenneth W. |
| Copyright Year | 1999 |
| Description | The subsonic, lateral-directional, stability and control derivatives of the thrust-vectoring F-1 8 High Angle of Attack Research Vehicle (HARV) are extracted from flight data using a maximum likelihood parameter identification technique. State noise is accounted for in the identification formulation and is used to model the uncommanded forcing functions caused by unsteady aerodynamics. Preprogrammed maneuvers provided independent control surface inputs, eliminating problems of identifiability related to correlations between the aircraft controls and states. The HARV derivatives are plotted as functions of angles of attack between 10deg and 70deg and compared to flight estimates from the basic F-18 aircraft and to predictions from ground and wind tunnel tests. Unlike maneuvers of the basic F-18 aircraft, the HARV maneuvers were very precise and repeatable, resulting in tightly clustered estimates with small uncertainty levels. Significant differences were found between flight and prediction; however, some of these differences may be attributed to differences in the range of sideslip or input amplitude over which a given derivative was evaluated, and to differences between the HARV external configuration and that of the basic F-18 aircraft, upon which most of the prediction was based. Some HARV derivative fairings have been adjusted using basic F-18 derivatives (with low uncertainties) to help account for differences in variable ranges and the lack of HARV maneuvers at certain angles of attack. |
| File Size | 4109486 |
| Page Count | 90 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19990019364 |
| Archival Resource Key | ark:/13960/t6vx5982p |
| Language | English |
| Publisher Date | 1999-01-01 |
| Access Restriction | Open |
| Subject Keyword | Aircraft Stability And Control Directional Stability Control Surfaces Wind Tunnel Tests Lateral Stability F-18 Aircraft Maximum Likelihood Estimates Angle of Attack Parameter Identification Aircraft Control Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
