Study On The Galloping Characteristics Of The Catenary Positive Feeder Of Lanzhou-Xinjiang High-Speed Railway And The Anti-Dance Effect Of Air Flow Spoiler Under The Pulsating Wind Field

Lanzhou-Xinjiang high-speed railway is distributed in Gansu and Xinjiang,China.It passes through five wind zones along the line,with strong wind,which poses a serious threat to the safe operation of high-speed trains.In order to ensure the safety of train operation,Lanzhou-Xinjiang high-speed railway has built a wind barrier along the railway in the windy section.When the strong wind blows through the windbreak along the railway,the incoming wind converges at the top of the windbreak,forming a local wind speed acceleration zone,causing the galloping of the positive feeder along the line.The severe galloping of the positive feeder leads to serious damage to the connecting fittings,increases the risk of accidents such as disconnection and disconnection of the positive feeder of the overhead contact system,and seriously threatens the safety of trains running along the Lanzhou-Xinjiang high-speed railway.Therefore,the phenomenon of ice free galloping along the Lanzhou-Xinjiang high-speed railway has important research significance,and the main research contents are as follows:(1)In the Matlab numerical simulation software,the linear filtering method and davenport wind power spectrum are used to simulate the fluctuating wind time history in the strong wind section of the Lanzhou-Xinjiang high-speed railway;creating a two-dimensional wind field model of the actual size of the positive feeder of the catenary,and mesh it in icem module;editing the profile file in fluent module to control the wind speed at the entrance of the wind field calculation domain,and calculating the wind speed time history at the positive feeder position and the static wind attack angle time history under the pulsating wind field.The inlet wind speed and the wind speed at the positive feeder position of the wind barrier flow field model were measured in a scaled wind tunnel,and the simulation results were compared with those of a two-dimensional wind field model.The results show that the fluid simulation results at the positive feeder position are consistent with the wind tunnel measurement results,and the wind speed at the positive feeder position is about twice the inlet wind speed,which verifies the accuracy of the fluid simulation of the positive feeder under fluctuating wind fields in high wind regions.(2)Based on the motion equation of the positive feeder,the expressions of the lift load and the drag load on the positive feeder are derived,taking into account the aerodynamic damping effect.Applying wind loads to the finite element model of a positive feeder,the effect of aerodynamic damping caused by the relative motion between the positive feeder and the incoming wind on the galloping response of the positive feeder was studied.Meanwhile,the aerodynamic damping calculation method given in the American Transmission Line Load Code is used to solve the galloping characteristics of the positive feeder line taking into account the aerodynamic damping.The frequency domain analysis of positive feeder galloping displacement without considering aerodynamic damping and positive feeder galloping displacement with considering aerodynamic damping is conducted to study the influence of aerodynamic damping on positive feeder galloping displacement in the frequency domain.The results show that the amplitude of positive feed galloping decreases significantly when aerodynamic damping is taken into account;The first order resonance effect of vertical displacement and horizontal displacement is significantly weakened,and the galloping trajectory obtained by the two calculation methods taking into account aerodynamic damping is relatively consistent,and the frequency domain characteristics of galloping displacement are also basically consistent.(3)A two-dimensional model of the positive feeder assembly is established after installing the spoiler,and divide the cross section of the positive feeder assembly with the spoiler installed into eight working conditions within a pitch.The flow field simulation of eight operating conditions is performed in fluent module to solve the aerodynamic characteristics of each operating condition.Calculating the galloping response of the positive feeder with 0.55 D,0.7D,and 0.85 D current disturbance arresters installed,and analyze the galloping amplitude of each size.The results show that the lift and resistance coefficients at45° and 270° operating conditions are the highest,while the lift and resistance coefficients at315° operating conditions are the lowest.After installing a 0.55 D spoiler,the positive feeder has the best anti dance effect.