| The Lanzhou-Urumqi High-speed Railway runs through the four major wind zones in Xinjiang,with long wind period,strong wind force and strong instantaneous destruction.In order to prevent the train from derailing under the influence of strong wind during operation,a wind wall was built along the railway to ensure the safety of the train.Because of the existence of the wind wall,the galloping of the positive feeder of catenary is aggravated,which seriously affects the safe operation of trains.When the positive feeder of catenary vibrates in the flow field,the positive feeder of catenary will generate different kinds of vibration when it is excited by wind,and the vibration of positive feeder of catenary will react to the flow field to form complex Fluid-Structure Interaction vibration.Therefore,in this thesis,aiming at the galloping phenomenon of the positive feeder of catenary,the galloping mechanism of the positive feeder of catenary without icing and the anti-galloping effect of pneumatic damping sheet are deeply studied by using the Fluid-Structure Interaction method.The main research contents are as follows:Firstly,the numerical calculation model of Fluid-Structure Interaction of catenary positive feeder is established,and the user-defined function(UDF)is written according to Runge-Kutta method to solve the motion control equation of positive feeder,and the real-time updating of grid is realized by using overlapping grid technology to realize the numerical calculation of Fluid-Structure Interaction vibration of rigid cylinder elastic support conductor.The aerodynamic and galloping characteristics of catenary positive feeder with and without walls are compared.The wind speed amplification coefficient at the position of positive feeder and the curve of wind attack angle changing with wind speed are determined by fluid mechanics software.Furthermore,the influence of the wind wall on the galloping of the positive feeder of catenary is clarified,which lays a foundation for the subsequent analysis of the galloping of the positive feeder and the anti-galloping effect of the anti-galloping device.Secondly,taking the two-dimensional catenary positive feeder model as the research object,the galloping response of catenary positive feeder is calculated by Fluid-Structure Interaction.The aerodynamic work under different frequency ratios and the energy balance of vertical and horizontal motions in a vibration period are analyzed,and the nonlinear vibration characteristics caused by aerodynamic coupling effect between motions with different degrees of freedom are described substantially.The galloping mechanism of catenary positive feeder under the influence of wind wall wake is clarified,and the galloping mode of catenary positive feeder is classified as Den.Hartog galloping without icing,which expands the classical Den.Hartog galloping theory.Finally,according to the theory of Den.Hartog and Nigol galloping,the safety of the positive feeder of catenary after installing damping sheet is verified.The influence of installing different damping sheet on the aerodynamic and galloping characteristics of the positive feeder of catenary is analyzed.According to the galloping characteristics of the positive feeder after installing damping sheet,the optimal angle of installing damping sheet is determined,and the influence of damping sheet structure size on the galloping of the positive feeder is analyzed.The research shows that the pneumatic damping sheet has a certain influence on the aerodynamic and galloping characteristics of the positive feeder,and has a certain preventive effect on the galloping of the positive feeder of catenary.The best anti-galloping effect can be achieved when the length of damping sheet boards with different suspension modes is 0.75 D. |
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