Abstract:

The method to calculate the air resistance caused by a single train running through long railway tunnels without auxiliary adit is discussed. A method to calculate the air resistance is established on basis of the unsteady flow and the pressure difference between the train nose and the train tail. The calculation method is verified by field trials and a lot of calculations are made for different train running conditions. The influences of the tunnel length, traintunnel dimension ratio, train speed and train length on the air resistance is analyzed. The calculation results show that the factor that has the greatest influence on the air resistance is the traintunnel dimension ratio, which is followed by train speed, tunnel length and train length.

Key words: long railway tunnel without auxiliary adit, single train, air resistance, unsteady flow, pressure difference, traintunnel dimension ratio