Numerical simulation of aerodynamic force on tarpaulin of railway vehicle under cross wind condition

Based on the three-dimensional, incompressible and steady Navier-Stokes equation and k-ε turbulence model, the complex three-dimensional flow field model around the tarpaulin was built when the freight vehicle runs through the wind area. The zero-thickness wall was used to simulate the tarpaulin in those models. Numerical simulation was adopted to carry out the aerodynamic force on the tarpaulin of railway freight vehicle in cross winds. The effect laws of the tarpaulin aerodynamics force were gained which were caused by the wind speed, the height of the cargo loading, the figure of the cargo loading and the sedimentation of the cargo. The aerodynamic forces of tarpaulins were gained when the freight vehicle runs under different conditions. The results show that when the speed of train remains unchanged, the aerodynamic lift coefficient of the tarpaulin is proportional to the wind speed. The lift force of the tarpaulin increases significantly with the increase of the height of the cargo loading, the lift force coefficient of 0.75 m tarpaulin height is larger than that of 0.45 m in height, and the increase value is 28%. When the figure of the cargo loading is circular arc, the lift force coefficient of the tarpaulin is much greater than when the figure is triangular, and the increase value is 28.3%. When the clearances between the tarpaulins and goods inside 0.02-0.12 m, the lift force of the tarpaulin increase with the increase of clearance. When the clearance is 0.12 m, the lift force coefficient is 14.5% larger than when the clearance is 0.02 m. The results show that the numerical calculation results and experimental results have a relative error of 7.1%, which proves the numerical calculation method is correct. ©, 2015, Central South University of Technology. All right reserved.