摘要 |
<p>12 Title of the Invention: AUTOMATIC CAMBER CONTROL Inventor: Douglas R. Frei Wind tunnel data for a three control surface aircraft is developed for lift, pitching moment, and drag coefficient characteristics. This data is then input into a Lagrange optimization program to determine a unique combination of canard, flap, and strake flap positions that trimmed the pitching moment coefficient to zero and provided the minimum drag coefficient as a function of lift coefficient and/or angle of attack, Mach number, and altitude. This program is exercised over the entire Mach number, altitude, and angle of attack range of the aircraft. The output from the Lagrange optimization program are then tabulated and loaded into the memory of a digital flight control computer of an aircraft. As the aircraft flies, the angle of attack sensor, air data sensor and altimeter determine the angle of attack, Mach number and altitude of the aircraft. By means of the computer, the position of the control surfaces are changed to the predetermined settings of the look-up table for minimum drag.</p> |