Development and study of a constructive solution for a single-track railroad tunnel for a high-speed railway line, with the account of aerodynamic processes

The materials presented in the article will be used in the dissertation submitted in partial fulfillment of the requirements for the degree of Ph.D. in Engineering Science. The article provides information on the construction and operation of a railroad tunnel for a high-speed railway line, it is noted that generally single-track railroad tunnels are constructed on new railway lines. A development review of existing methods for reducing and compensating aerodynamic pressure and ways of its regulation is given, and its advantages and disadvantages are analyzed. A new design solution description that helps to reduce the intensity of the aerodynamic effect is presented, the principles of its operation and the main hypothesis are described, and advantages over existing solutions are shown. The study materials of the aerodynamic state of the «tunnel-train» system, obtained from the numerical simulation results by the methods of computational fluid dynamics, are presented. An analysis of the change in aerodynamic pressure for various parameters of the passage of a train in a tunnel has been carried out, and the «tunnel-train» system state assessment has been given. The main attention is paid to the influence degree of the train speed, the cross-sectional areas ratio, and tunnel and train lengths. The numerical modeling results were evaluated by the aerodynamic pressure drop values, by the nature of the aerodynamic state of the «tunnel-train» system, by the nature of the air flows, and by its speed trajectories. The obtained results are presented in tabular and graphic forms, and results analysis is carried out. The effectiveness of a new design solution for a tunnel for a high-speed railway line in solving the problem of mitigating aerodynamic pressure is shown, and the rationality of the engineering solution is substantiated. The constructive solution of the tunnel for a high-speed railway line has the potential to reduce material consumption and improve the technical and economic characteristics of the structure and can be used in the design and construction for further efficient operation of perspective high-speed railway lines in modern conditions, with the account aerodynamic phenomena.