The Maximum Likelihood parameter-estimation algorithm was used to extract the longitudinal aerodynamics derivative from flight data for the Handley Page HP 115 slender delta-wing research aircraft. The responses in the rate of pitch and vertical acceleration were excited from the horizontal steady-state flights at different air speeds by the elevon deflection. In some cases the measured time histories were converted into frequency response curves, from which the unknown parameters were estimated. For the low angle of attack measurements the linear model of the aircraft was adequate, whereas for the runs measured at high angle of attacks the non-linear model had to be used. Some indentifiability problems were met because of the limited number of measured outputs and incorrect design of the experiment. The non-dimensional aerodynamic derivatives extracted were compared with those from wind-tunnel tests and steady-state measurements. A reasonable degree of consistency between the various sets of results was obtained. (Author)
Longitudinal Aerodynamic Derivatives of a Slender delta Wing Research Aircraft Extracted from Flight Data
1974
85 pages
Report
Keine Angabe
Englisch