Double layer air current during the high speed train flow-around

Abstract

Purpose. Investigation of the jet stream mechanism during the high-speed passenger train flow around. On the basis of theoretical studies to determine the distribution of air flow velocity field, the pressure on the upper layer of the double layer air current, the pressure at the boundary of both layers of double-layer air current. Methodology. To solve the problem on the top layer of air current the Zhukovsky method and the method of theory of ideal incompressible fluid jets was applied. Then to solve the boundary layer equations the pressure at the boundary of both layers was determined, the Navier - Stokes equation, which takes into account the influence of the top layer on the bottom layer was set up. Airflow in the upper region is a potential, stationary; the air in the vicinity is considered as the compressible one. Findings. The distribution of the velocity field for both layers of air current was obtained. The pressure on the upper layer of the double layer air flow was defined. Originality. The problem of a double layer air current formed by the high-speed train movement consisting of the boundary layer above the car surfaces and the air current with no viscosity was studied for the first time. Practical value. The problem under study is used to provide the safety of high-speed train traffic.

Keywords

• potential
• the method of the jet theory
• boundary layer
• jet air current
• traffic safety