Influence Analysis Of Track Structure On Wind-sand Flow Control Performance

China is one of the most widely distributed countries in the world,and the desert blocks the economic and cultural exchanges between parts and regions.While the railway transport in the desert,the Gobi and sand and other areas play a huge role.China's railway workers have long started the experimental work of the desert railway,and obtained a large number of desert railway construction technology achievements,successfully built to Baotou Lan,Lan Xin Railway as the representative of a number of desert railway.However,due to the natural environment constraints,the construction and maintenance of railway tracks are always faced with the erosion of sandstorms,seriously affecting the normal operation of the train.Aiming at the wind erosion and sand burial on the desert railway,many preventive measures have been put forward by the researchers at home and abroad.However,it is necessary to analyze the law of the movement of the wind and sand flow around the different orbital structures.Therefore,it is necessary to further study the flow field around the different orbital structures Research.The ballast track and the ballastless track are used as the two different rail structures in the railway transportation.The FLUENT software is used to simulate the flow of the wind and sand flow around two different orbital structures.Flow field characteristics,to explore the ballast track and ballastless track structure under the sand and sand flow law and sand accumulation process,and then introduced a known as the "hump plate track" of the upper structure,the structure to a large extent able to eliminate the desert railway main problem.The system utilizes the main advantage of the ballastless track,that is,the ballast layer is removed to avoid filling the ballast voids through the dunes.Since the upper part of the hump orbit is higher than that of the reinforced concrete slabs,the dunes can be carried out between the upper and lower tracks Horizontal transmission.The results show that the ballast size of the ballasted track structure is obviously larger than that of the sand grain,and the wind speed is smaller when the wind and sand flow are close to the ground.The sand is moving forward along the ground,and the sand has a hindrance to the wind speed.Above the ground,sand under the action of the wind to accelerate the trend of movement to reach the orbital structure,the wind speed weakened,part of the sand to stay to form sand,sand filled the entire bed bed,with the increase of time,sand accumulation in the whole.At t = 1s,the cumulative area of sand which is more than 30 pa is 52%,when t = 2s,the accumulated area of sand above the pressure is 76%,and the pressure of the sand around the whole track structure increased by 21%,Above the track structure,the formation of sand buried railway phenomenon.Due to the difference in the structure of the track,the law of the flow field around the ballastless track is very different from the ballast track.First,the concrete structure replaces the ballast,the sand can pass through the whole track quickly,and the sand is not easy to form around the track In addition,due to the presence of large angle spiral winds in the concrete pillow and the desert area,the sand that has accumulated around the track continues to lift the wind.At t = 1s,the cumulative area of sand which is more than 30 pa is 42%,and the accumulated area of sand at this pressure is only 46%,at t = 2s.The pressure of sand around the whole track structure increases 6%,the clear sand exists only in the concrete pillow,the phenomenon of sand buried railway around the formation ballastless track do not appear.