Abstract:

Wind-blown sand movement often leads to sand deposition on the tracks of desert railways， and it severely affects the diving efficiency and operation safety. To alleviate sand deposition on railway tracks， many scholars have designed relevant preventive facilities for sand deposition on railway tracks by using the method of flow field regulation. In this paper， the impacts of sediment baffles with the same height as the rail and different geometric sections placed in ballastless track on the flow field in the track and the dust accumulation process were studied using Eulerian-Eulerian two-fluid model. The results suggest that the 30°， 45° and 60° inclined baffles， rectangular baffle and right-angled isosceles triangular baffle with the height of 175 mm， when placed in ballastless track， can reduce the volume fraction ratio of sand in the track by 7.98%， 5.52%， 4.56%， 7.89% and 6.83%， respectively. This shows that sediment baffles can effectively curb the sand deposition in the track， among which the 30° inclined baffle performs the best. This is mainly due to the fact that after the sediment baffles are placed， the curve change of horizontal wind speed in the track shapes like an “M”， and the flow velocity on both sides of the baffle increases significantly. This change will significantly increase the movement distance of sand， thus reducing sand deposition in the track. The findings in this paper can provide some new ideas for the prevention and control of sand burial damage to railways in desert areas.

Key words: sand accumulation in track, wind-sand two-phase flow, sediment baffles, flow field uplift