School of Railway Eng., Iran University of Science and Technology, Tehran, 1684613114, Iran
Reduction in weight adjoined with the increase in the railway vehicle speed of travel added to the deteriorating effects of the crosswinds on the running behavior of high speed trains. During the past decade, many researchers have concentrated on examining the aerodynamic force and moment coefficients for the trains. Varieties of studies regarding the effects of crosswinds on the trains are accomplished. However, the need to restrain strong winds from disturbing trains running safety is not completed. This research is concerned with finding a proper solution for attenuating the worrying effects of the winds that hit the trains. Installation of air fences on the sides of the railway tracks is investigated. To serve the purpose, a variety of air fences with different heights, with and without the edges on top of the fences, at a variety of the edge lengths and angles are studied. The study covers double routed railway track while the air fences are installed on either side of the track. The train can be on the leeward or windward line. The problem solving is based on the Lattice-Boltzmann method. This research pioneers in using this method for the said purpose. It is found that by inserting the fences and increasing their heights for up to 1m, the drag forces decrease to 40 percent and the rolling moment coefficients decrease to 15 percent. The presence of the edge can also decrease the drag force for about 55 to 120 percent and decrease the rolling moment coefficients for about 30 to 115 percent in some cases. Variations in percentages of reduction are due to the different angles and the lengths of the edges.