Wind tunnel test of rolling maneuver load alleviation

It has been documented that maneuver load alleviation possesses a strong potency for reducing structure weight which would improve flight performance in the field of aircraft design. In view of this situation, a wind tunnel test was designed and conducted in this study to evaluate the control method of rolling maneuver load alleviation (RMLA) with multiple control surfaces. According to the demands for test, a series of models and procedures were designed, including the test aircraft model with a normal layout and a small aspect ratio, rolling and limiting device, measurement and control system based on test model, zero-degree keeping circuit, and RMLA control systems. The test was conducted using two control laws with different combinations of control surfaces to evaluate the effects on load alleviation. It was found that, compared with baseline control law, the additional maneuver load generated during the process of rolling maneuver was effectively alleviated using the method of simultaneously deflecting multiple control surfaces. The control law 1 with the simultaneous deflection of wing and trailing-edge outboard (TEO) control surface alleviated the bending and torsion moments of wing by 30.1% and 38.0%, respectively, and the bending and torsion moments of empennage by 57.9% and 12.5%, respectively. The control law 2 with the simultaneous deflection of wing, TEO, and trailing-edge inboard (TEI) control surfaces alleviated the bending and torsion moments of wing by 33.0% and 35.5%, respectively, and the bending and torsion moments of empennage by 45.7% and 54.8%, respectively.