Implementation of roll motion in magnetic suspension wind tunnel

Abstract

Wind tunnel tests are generally obstructed by model support with limitations. The development of magnetic suspension wind tunnel (MSWT) is designed to free the model from conventional mechanical supports. Under precise model design, a roll motion with appropriate control can be implemented in MSWT. This paper presents a modification of NCKU 10 cm/spl times/10 cm MSWT to accomplish the roll motion control in wind tunnel tests. The modification of this experiment includes position and attitude sensing and test model design. The position and attitude sensing is improved and set-up by a laser-optical circuit, quadrant detectors and dual-lateral detector in x-axis to ensure accurate measure. The rolling inertia is generated from a rotating mass inside the test model. With very careful design, a rocket model is fabricated for experiments. A passive PID control is implemented to achieve the predictable constant roll motion on the test model. A current feedback loop is applied to strengthen the control stability. Being different from other MSWT applications, the test model is locked by the position and attitude sensing via feedback control loop. Due to the accomplishment of motion test roll only constant speed in good control limitations, demonstrates performance. The idea of this study is to extend dynamic test capability in the magnetic suspension wind tunnel, and bring further valuable applications.