Study on Dynamic Characteristics of Sound Barriers

Abstract

Using the commercial code FLUENT analyzes the characteristics of aerodynamic impulse force on sound barriers when high-speed trains pass by the sound barriers.The analysis considers effect of the different heads of sound barrier with different heights on the characteristics of aerodynamic impulse force on the sound barrier.The different heads of sound barrier include the up-right wall,the type Y,the interior inverse L type and the external inverse L type.Two different heights of sound barrier are used in the calculation.Two kinds of aerodynamic exteriors of high-speed train(A and B) are considered.The operation speed of the train is 350 km/h.Also using the commercial code ANSYS develops the finite element models of the sound barriers to calculate the natural frequencies and modes of the sound barriers,and calculate the transient response to the aerodynamic impulse force caused by the high-speed train.The numerical results show that the variation tendencies of the aerodynamic impulse pressure on the sound barriers with different head structures are close,the impulse airflow on the sound barriers has the remarkable effect of bow wave and trailing wave when the train pass by at high-speed.There are some differences at the peaks of the aerodynamic impulse pressure.The peak value of the aerodynamic impulse pressure on the Y type sound barrier is the maximum,it is the less maximum on the interior inverse "L" sound barrier and the peak value of the aerodynamic impulse pressure on the external inverse L type sound barrier is the minimum.There is a big difference between the reaction forces at the bottoms of stand columns of the sound barriers with heights of 2.15 m and 3.15 m.The analyzed sound barriers have the fundamental resonant frequency higher than the frequencies of the aerodynamic impulse force.Therefore,the resonance does not occurs on the sound barriers when the train passes by at 350 km/h.