Study On The Analysis Method Of Motion Characteristics Of VSV Regulating Mechanism

Surging can cause great damage to aero-engines. Variable stator vane regulatory mechanism is widely used in most aero-engines to protect the aero-engines from surging when working in the off-design point. Kinematics and dynamics characteristics are related to the safety of aero-planes.Numerical simulation method, mathematical modeling method, and experiment method of variable stator vane regulatory mechanism are presented in this study, as following:(1)Numerical simulation based on software ADAMS is performed on regulatory mechanism. The cranks’ angle, vanes’ angle and driving force of actuating cylinder varied linearly following the driving displacement, basically. It can be drawn that regulatory mechanism runs smoothly, and displacement or force saltation does not appear. The mechanism is a reasonable design. The treatment of rocker arm as rigid body and driving velocity make little influence on driving force. However, the influent of friction can’t be ignored.(2)Mathematical models including kinematics and dynamics models based on modified D-H matrix method and NEWTON-EULER method are developed on regulatory mechanism. Inertia force, friction are analyzed and simplified. The results including angles and forces of numerical simulation coincidence those of mathematical modeling, with less than three percent relative error.(3)Experiments including friction coefficient measurement and motion characteristics measurement are performed. Friction coefficient measurement experiment measure the friction coefficients of joints of regulatory mechanism. And the difference between the vanes’ angles of experiment and mathematical modeling is less than five percent. Unknown extra resistance is observed in the experiments, which affects the measurement of the driving force. However, the effect decreases following the increase of external forces, and can be ignored when external forces reach to a certain value. The difference between the driving forces is less than ten percent. Correctness of mathematical modeling method is verified.(4)Influence of parameters including size parameters, position parameters and friction coefficients on vanes’ angle and driving force is compared through sensitivity analysis of regulatory mechanism. The sensitivities of vanes’ angle are similar to that of driving force, but higher. So the influence of parameters on vanes’ angle is consistent to that on driving force. Besides, parameters of the third crank, IGV crank and rocker arm affect motion characteristics apparently. These components should be to focus on design and machining.Study on motion characteristics of variable stator vane regulatory mechanism can be applied to structural optimization, processing precision control and repairing.