Giant magnetostrictive actuators (GMAs) often work in a close-loop feedback system. This system needs independent sensors which may be difficult to be fixed, besides, excessive sensors may cause more unpredicted probl...Giant magnetostrictive actuators (GMAs) often work in a close-loop feedback system. This system needs independent sensors which may be difficult to be fixed, besides, excessive sensors may cause more unpredicted problems in a large system. This paper aims to develop a self-sensing GMA. An observer based on piezomagnetic equations is constructed to estimate the stress and strain of the magnetostrictive material. The observer based self-sensing approach depends on the facts that the magnetic field is controllable and that the magnetic induction is measurable. Aiming at the nonlinear hysteresis in magnetization, a hys- teresis compensation observer based on Preisach model is developed. Experiment verified the availability of the observer approach, and the hysteresis compensation observer has higher tracking precision than linear observer for dynamic force sensing.展开更多
A novel circulation control technique is proposed to overcome the shortcomings of blowing jet circulation control, which uses the synthetic jet as the actuator and avoids the limitation about air supply requirement. T...A novel circulation control technique is proposed to overcome the shortcomings of blowing jet circulation control, which uses the synthetic jet as the actuator and avoids the limitation about air supply requirement. The effectiveness of synthetic jet circulation control to enhance lift of NCCR1510-7067N airfoil is confirmed by solving the 2-D unsteady Reynolds-averaged Na- vier-Stokes equations. The aerodynamic characteristics and the flow structure （especially close to the trailing edge） of NCCR 1510-7067N airfoil at zero angle of attack are also presented to discuss the mechanism of lift enhancement of the airfoil with synthetic jet circulation control. The results indicate that the synthetic jet can effectively delay the separation point on the airfoil trailing edge and increase the circulation and lift of the airfoil by Coanda effect. The numerical simulation results demonstrate that the lift augmentation efficiency with synthetic jet circulation control reaches △C1/Cμ,=114 in the present study, which is much higher than the value 12.1 in the case with steady blowing jet circulation control.展开更多
基金Project supported by the National Natural Science Foundation ofChina (No. 50105019)the China Postdoctoral Science Foundation (No. 20060390337)
文摘Giant magnetostrictive actuators (GMAs) often work in a close-loop feedback system. This system needs independent sensors which may be difficult to be fixed, besides, excessive sensors may cause more unpredicted problems in a large system. This paper aims to develop a self-sensing GMA. An observer based on piezomagnetic equations is constructed to estimate the stress and strain of the magnetostrictive material. The observer based self-sensing approach depends on the facts that the magnetic field is controllable and that the magnetic induction is measurable. Aiming at the nonlinear hysteresis in magnetization, a hys- teresis compensation observer based on Preisach model is developed. Experiment verified the availability of the observer approach, and the hysteresis compensation observer has higher tracking precision than linear observer for dynamic force sensing.
基金supported by the National Natural Science Foundation of China (Grant No. 10872021)the Open Research Project of the State Key Laboratory of Mechanical System and Vibration (Grant No. MSV-2012-09)
文摘A novel circulation control technique is proposed to overcome the shortcomings of blowing jet circulation control, which uses the synthetic jet as the actuator and avoids the limitation about air supply requirement. The effectiveness of synthetic jet circulation control to enhance lift of NCCR1510-7067N airfoil is confirmed by solving the 2-D unsteady Reynolds-averaged Na- vier-Stokes equations. The aerodynamic characteristics and the flow structure （especially close to the trailing edge） of NCCR 1510-7067N airfoil at zero angle of attack are also presented to discuss the mechanism of lift enhancement of the airfoil with synthetic jet circulation control. The results indicate that the synthetic jet can effectively delay the separation point on the airfoil trailing edge and increase the circulation and lift of the airfoil by Coanda effect. The numerical simulation results demonstrate that the lift augmentation efficiency with synthetic jet circulation control reaches △C1/Cμ,=114 in the present study, which is much higher than the value 12.1 in the case with steady blowing jet circulation control.
