Theoretical Analysis And Experimental Research On Unsteady Aerodynamic Hinge Moment

This reasearch of this thesis is based on a pratical from space institute.In order to improve the control precision of the aircraft’s air rudder,a series of performance tests of the air rudder servo system are required on the ground,mainly including steady torque loading and unsteady torque loading.The steady aerodynamic hinge-moment is simulated by the load simulator,while this thesis aims to study the unsteady aerodynamic force solving the problem of unsteady aerodynamic time domain simulation and the problems of pneumatic output,precision control,and the optimization of excitation points and the vibration point.Further more a complete unsteady aerodynamic hinge-moment experimental system is established.The research contents are summarized as the following:(1)By analysis of the binary-wing segment model and the relationship between the unsteady aerodynamic force and the structure,the calculation process of aeroelastic-induced flutter is deduced.The correlation between flutter frequency and flutter speed of binary-wing section and structural parameters is obtained,which verifies the feasibility of unsteady aerodynamic hinge-moment experimental system.(2)The unsteady aerodynamic time-domain simulation and excitation force control performance are two difficult issues to deal with.This thesis has established the mathematical relationship of the rigid wing aerodynamic force through analying the aerodynamic calculation method of piston theory and dipole grid method.In addition the aerodynamic conversion from frequency-domain to time-domain with minimum state method is completed.An optimization model is established to localize of the aerodynamic reduction point by genetic algorithm,with the objective of vibration mode of the key flutter.The mechanical properties of the vibrator are studied and the control performance of the vibrator is simulated and tested.(3)The hardware structure and the control system of the experimental system is designed.It is able to carry out preliminary experiments.(4)Taking the flat wing as the research object,the force control performance of the vibrator is investigated.The results show that the force control method can meet the requirements of the test system.