The Analysis Of Vibration Isolation Technology Of Uav's Reciprocating Internal-combustion Engine

Vibration is commonly found in the industrial manufactures and daily life,which causes a certain degree of damages,especially after using the engine as a driving force, which is becoming more prominent. With the increasing social progress and the continuous development of science and technology, people urgently ask for higher requirements of vibration control, and good stability is considered as an important indication of the system. In this dissertation,based on summarizing and absorbing the achievement in the pioneer works, I systematically study the vibration of the homemade HS-700 reciprocating internal-combustion engine of unmanned aerial vehicle(UAV),and design the damping and vibration islation for the reciprocating internal-combustion engine with air-spring that used as vibration isolatior.The theoretical result of damping and vibration islation are satisfying very well, and the main research works is as follow:(1) By the structure theory of air-spring and aerothermodynamics,the author deduces the nonlinear stiffness'equation of air-spring,and establishes nonlinear dynamic model of two-degree-of-freedom of reciprocating internal-combustion engine of UAV.Owing to consider nonlinear stiffness of air-spring, the model is more consistent with the actual situation.(2) Nonlinear dynamic model of two-degree-of-freedom of reciprocating internal-combustion engine of UAV is simulated by using fourth-order Runge-Kutta method (ODE45) of Matlab. The response curve of the system is drawed, which gives a way that how to selected parameters for the vibration isolatior, and provides a theoretical basis for vibration control of engine.(3) Based on the given data, the elementary model of free film air-spring is drawed, and the manufacturing technics of air-spring is briefly illustrated, it can be as references for technicians of air-spring manufacturing.