چكيده به لاتين
Research on crosswind on trains since the 1990s was noted with the growth of high speed trains. The crosswind is a safety issue and a key factor that can prevent the speed continuous increase of rail transport vehicles. The study of the effects of crosswind on trains requires a comprehensive overview. In this thesis, while studying the aerodynamics of air flow on a sample of high-speed trains under the influence of crosswinds, and due to the very important impact of infrastructure and the fact that any change in the environment around the train causes a change in the air flow, the effect of the windbreaks is investigated. In the first step, two-dimensional calculations are performed to study the parametric design of the windbreak and validate the values of simplified models. This is done to show the validity of the two-dimensional models and to find a set of windbreak designs for more accurate simulations in 3D space. The proposed solution is based on the simulation of Computational Fluid Dynamics (CFD) with the Lattice Boltzmann Method (LBM). In the second step, by constructing a scale-based sample of high speed train and windbreaks and conducting wind tunnel experiments, trying to validate the results of two-dimensional simulations. In the third step, the aerodynamic coefficients of the high-speed train are measured using some wall designs used in the two-dimensional model to measure the effect of the windbreaks in 3D space and see the phenomenon of three-dimensional flow behind the windbreaks. In this thesis, different types of windbreaks will be compared with different geometric shapes. The windbreaks were compared with respect to height, edge of the wall, porosity and different installation distances to the train. Finally, in the fourth step, using the Genetic Algorithm as one of the optimization methods, the optimal structure for the shape, height and location of the windbreak installation was obtained and introduced. The results of this thesis can be used to enhance safety issues in the design and operation of high speed rail lines. The proper design of the windbreaks can greatly reduce the destructive effects of crosswinds, and inappropriate design itself can be an exaggeration factor along the crosswind and endangers the stability of the train.
