Research On Aerodynamic Characteristics Of Positive Feeder Of Overhead Contact System In Strong Wind Zone Of Lanzhou-xinjiang High-speed Railway

As an important component of China's western railway network,Lanzhou-Xinjiang High-speed Railway is of great significance for speeding up the development of Western China,enhancing transport capacity and promoting the construction of "one belt and one road" economic belt.The geological environment along Lanzhou-Xinjiang Railway is complex and runs through four wind regions in Xinjiang.It is one of the serious railway disaster areas.In order to prevent the train from being overturned by the gale,the windbreak wall was set up along the strong wind zone of Lanzhou-Xinjiang railway.However,through on-site investigation and research,it is found that the positive feeder of the windshield section of Lanzhou-Xinjiang Railway is more prone to violent galloping than that of the non-wall section,which leads to line tripping,severe wear and tear of armour clamp and other faults,seriously affecting the operation safety of Lanzhou-Xinjiang Railway.In order to ensure the normal operation of the train,it is necessary to study the galloping of the positive feeder.Because the change of air flow is the direct cause of conductor galloping,the aerodynamic characteristics of positive feeder in strong wind zone of Lanzhou-Xinjiang Railway are studied in this thesis.In this thesis,based on computational fluid dynamics theory,a two-dimensional model of catenary positive feeder in strong wind zone is established by using simulation software.Firstly,the influence of the windbreak wall on airflow at different wind speeds was studied in the thesis,including the magnitude and direction of wind speed.Secondly,the positive feeder model without wall and with wall were established to study the aerodynamic characteristics of the positive feeder.The aerodynamic coefficients of the positive feeder under different wind speeds were obtained.Finally,taking the wind speed of 15m/s as an example,the influence of the structure of the windbreak wall and the spatial position of the positive feeder on the aerodynamic characteristics of the positive feeder was studied.The results show that:(1)The windbreak wall has a strong convergence effect on the airflow.Under the influence of the windbreak wall,the airflow grows faster,and the wind speed at the position of the positive feeder has a vertical component.As the wind speed increases,so does the wind attack angle.When the wind speed increases to 15m/s,the angle of attack is basically stable at 29°~30°.(2)Under the same wind speed,the aerodynamic coefficients of the positive feeder with walls are much larger than those of the positive feeder without walls,which is an important reason for the violent galloping of the positive feeder in the windbreak wall section of Lanzhou-Xinjiang Railway.(3)The structure of the windbreak wall and the spatial position of the positive feeder have great influence on the aerodynamic characteristics of the positive feeder.Among all the influencing factors,the vertical height of positive feeder has obvious influence.When the positive feeder is located at the height of 3.0m~5.0m,the aerodynamic coefficient is the minimum,and the lift coefficient curve is basically no longer oscillating,which cannot provide alternating force for the positive feeder to dance,thus reducing the probability of dancing.