Study On Pressure Wave Of High Speed Metro Tunnel

With the needs of urban development,cities have higher requirements for the speed of metro trains.At the same time as the driving speed increases,the pressure wave effect caused by the high-speed metro train running in the tunnel is more obvious and complex,which will affect the comfort of passengers and the changes of the train body,thereby affecting the safety of metro operation.At present,my country’s research on pressure waves in tunnels mainly uses three-dimensional algorithms or one-dimensional algorithms.Article uses a more efficient one-dimensional/three-dimensional coupling calculation method for research.The research content of this paper provides data support for the design of metro trains and tunnels.This article provides data support for the design of metro and tunnels.This article builds a metro and tunnel model based on a domestic B-type metro and Dongguan R2 line tunnel.Numerical simulation combines the advantages of one-dimensional algorithm and three-dimensional algorithm,and adopts one-dimensional/three-dimensional coupling calculation method to analyze the pressure waves caused by high-speed metro trains running in simple tunnels and interval tunnels with a vertical shaft at different speeds.The effect is systematically studied.Main tasks as follows:(1)A numerical calculation model and calculation method are established,and the results of the one-dimensional/three-dimensional coupling algorithm are compared with the three-dimensional algorithm to verify the correctness of the calculation method.The comparison shows that the calculation results of the two algorithms are relatively consistent,the pressure fluctuations are the same,there is no big difference,and the difference between pressure and velocity changes are generally within 5%,which shows that the calculation method of one-dimensional /three-dimensional coupling can accurately reflects the pressure fluctuation effect caused by the metro train running in the tunnel;compared with the three-dimensional algorithm,the calculation time of the one-dimensional and three-dimensional coupling method is shorter.(2)It reveals the changes of the pressure wave when the train runs in a simple tunnel,and the influence of speed on the pressure wave in the tunnel.Studies have shown that the pressure in the tunnel rises rapidly at the beginning of the train,and reaches the maximum value.Due to the change of the airflow direction,the pressure drops to negative pressure.After that,the superimposition of the compression wave and the expansion wave causes the pressure to change repeatedly;the pressure in the tunnel changes.The maximum value of and the maximum value of pressure change at the front and rear of the train are both increased with the increase of train speed.(3)The pressure variation law of the train running in a complex tunnel,and the influence of shaft and speed on the pressure in the tunnel are studied.Studies have shown that when the train is running,a positive pressure zone is formed at the front of the train and a large negative pressure zone is formed at the rear of the train.When passing near the shaft,the pressure on the surface of the car body and the tunnel will change suddenly.The farther away from the tunnel entrance,the pressure will increase.The fluctuation tends to be stable;the maximum positive pressure value at the front of the car and the maximum negative pressure value at the rear of the car both increase with the increase of the train speed,and the maximum change of the pressure in the tunnel also increases with the increase of the train speed;The pressure in the shaft fluctuates more than the pressure at the head of the shaft,and the pressure generated in the tunnel is smaller than the pressure value without shaft.The maximum value of the pressure change every 1.0 second and every1.7 seconds increases with the increase of the vehicle speed,and the change every 1.7 seconds looks the most obvious.