Study On The Anti-galloping Effectiveness Of Catenary Positive Feeder Cable-stayed Insulator And Air Flow Spoiler In The Strong Wind Areas Of Lanzhou–urumqi High-speed Railway

The Lanzhou–Urumqi high-speed railway is the world’s longest electrified high-speed railway with the longest open to traffic.It passes through the five windy areas in Xinjiang and Gansu.The environment is harsh and the wind disaster is severe,which will directly threaten the safe operation of high-speed trains.In order to effectively avoid the overturning accident of the train,a wind-proof wall is built along the railway line in the wind areas.Although the installation of the wind-proof wall can prevent the train from being derailed by wind and the track from being buried in sand,it has aggravated the galloping phenomenon of the positive feeder,caused serious wear and tear of clues and fittings,prone to disconnection accidents,which is a great impact on the safe operation of electrified railways.Therefore,it is necessary to study the effectiveness of anti-galloping devices for catenary positive feeders in combination with vibration mechanics.Firstly,according to the large-span and highly flexible suspension cable structure characteristics of the catenary positive feeder,it can be simplified to a single-span conductor with two ends constrained.The parabola method in the analytical method is used to find the shape-finding solution for the initial state of the positive feeder when it reaches equilibrium under the load of its own weight.The parameters needed in the finite element modeling of catenary positive feeder are calculated,and the shape finding calculation of the positive feeder is carried out by using the finite element method.Compared with the analytical method,the correctness of the shape finding of the positive feeder by the finite element method is verified,which lays the foundation for the subsequent dynamic analysis.Secondly,the aerodynamic excitation of the catenary positive feeder behind the windbreak is analyzed and calculated.Combined with the wind tunnel test of the wind speed changes before and after the windbreak and the corresponding scale model simulation results,the correctness and effectiveness of the full-scale model established when studying the aerodynamic characteristics of the catenary positive feeder are verified.Then,according to the nonlinear finite element theory to simulate the galloping time history of the catenary positive feeder under aerodynamic loads,and the galloping response before and after the installation of the cable-stayed insulator anti-galloping device on the positive feeder is compared,including the time history response of galloping amplitude and tension change,so as to analyze the anti-galloping effectiveness of cable-stayed insulator on the catenary positive feeder.Finally,the aerodynamic characteristics of the composite cross section with different phases formed after installing the air flow spoiler in the catenary positive feeder are simulated by using the computational fluid dynamic,and the aerodynamic coefficient curve is measured.Combined with the flow field change diagram of the tail after installing the air flow spoiler,whether the air flow spoiler can restrain the positive feeder galloping is analyzed.Then,three kinds of air flow spoiler with different diameters are compared and analyzed.The results show that the number and size of vortices generated in the wake area of different composite body sections at the same time are different after the installation of the air flow spoiler.The aerodynamic coefficients after installing different diameter air flow spoiler are lower than those without installing the air flow spoiler,which has a good anti-galloping effect,and the anti-galloping effect of 0.75 D spoiler is better than that of 0.5D and 0.9D spoiler.