The structure and principle of the GMM actuator and the new nozzle flapper valve with the GMA were presented. Based on the axis-symmetric FEM model of the GMA driving magnetic field was computed. And the field distrib...The structure and principle of the GMM actuator and the new nozzle flapper valve with the GMA were presented. Based on the axis-symmetric FEM model of the GMA driving magnetic field was computed. And the field distribution for different input currents and variant curves of magnetic flux density along the axis were determined by using FEM. Magnetic flux density of the GMM actuator was practically measured under different input currents. The experiment of output displacement and frequency response of the GMM actuator was carried out under typical working conditions. The experiment results show that the GMA for nozzle flapper servo valve has bigger output displacement and quick response speed. And theoretical basis was presented to further introduce the GMA nozzle flapper valve into two stage electro-hydraulic servooo valve.展开更多
This paper presents the fundamentals of a continuous adjoint method and the applications of this method to the aerodynamic design optimization of both external and internal flows.General formulation of the continuous ...This paper presents the fundamentals of a continuous adjoint method and the applications of this method to the aerodynamic design optimization of both external and internal flows.General formulation of the continuous adjoint equations and the corresponding boundary conditions are derived.With the adjoint method,the complete gradient information needed in the design optimization can be obtained by solving the governing flow equations and the corresponding adjoint equations only once for each cost function,regardless of the number of design parameters.An inverse design of airfoil is firstly performed to study the accuracy of the adjoint gradient and the effectiveness of the adjoint method as an inverse design method.Then the method is used to perform a series of single and multiple point design optimization problems involving the drag reduction of airfoil,wing,and wing-body configuration,and the aerodynamic performance improvement of turbine and compressor blade rows.The results demonstrate that the continuous adjoint method can efficiently and significantly improve the aerodynamic performance of the design in a shape optimization problem.展开更多
文摘The structure and principle of the GMM actuator and the new nozzle flapper valve with the GMA were presented. Based on the axis-symmetric FEM model of the GMA driving magnetic field was computed. And the field distribution for different input currents and variant curves of magnetic flux density along the axis were determined by using FEM. Magnetic flux density of the GMM actuator was practically measured under different input currents. The experiment of output displacement and frequency response of the GMM actuator was carried out under typical working conditions. The experiment results show that the GMA for nozzle flapper servo valve has bigger output displacement and quick response speed. And theoretical basis was presented to further introduce the GMA nozzle flapper valve into two stage electro-hydraulic servooo valve.
基金supported by the National Natural Science Foundation of China(Grant Nos.51206003 and 51376009)the National Science Foundation for Post-doctoral Scientists of China(Grant Nos.2012M510267 and 2013T60035)
文摘This paper presents the fundamentals of a continuous adjoint method and the applications of this method to the aerodynamic design optimization of both external and internal flows.General formulation of the continuous adjoint equations and the corresponding boundary conditions are derived.With the adjoint method,the complete gradient information needed in the design optimization can be obtained by solving the governing flow equations and the corresponding adjoint equations only once for each cost function,regardless of the number of design parameters.An inverse design of airfoil is firstly performed to study the accuracy of the adjoint gradient and the effectiveness of the adjoint method as an inverse design method.Then the method is used to perform a series of single and multiple point design optimization problems involving the drag reduction of airfoil,wing,and wing-body configuration,and the aerodynamic performance improvement of turbine and compressor blade rows.The results demonstrate that the continuous adjoint method can efficiently and significantly improve the aerodynamic performance of the design in a shape optimization problem.
