Test study on aerodynamic load and air-tightness characteristic of 250 km/h EMU
In order to provide load boundary input conditions for the fatigue and static strength of the active train body during long-term operation,and to strengthen the long-term operation and evaluation of the air-tightness of the train body and the internal pressure comfort,the aerodynamic load and frequency characteristics of the CRH5A high-speed train were studied by actual train test,the internal and external pressure wave and the characteristics of the internal and external pressure comfort under tunnel conditions were obtained.Combining actual test data and the analysis method for the whole train dynamic air-tightness index,the dynamic air-tightness index of the whole train was calculated.The results indicate that the variation range of pressure difference on the train body in Shenyang—Chaoyang test section of the Beijing—Shenyang passenger dedicated line is-2.53-0.71 kPa.There is no obvious dominant frequency of pressure on both sides outside the train body.The aerodynamic load does not affect the vibration and overturning of the train body.The maximum internal pressures are 294 Pa and 383 Pa at the time interval of 1 s and 3 s,respectively.The interior pressure fluctuates the most in the rear car.The air-tightness indexes of the whole train passing through the Heishan,Xiawobao,Koumo,Sanlenshan Tunnels are 10.46,12.13,11.06 and 14.40 s,respectively.The dynamic air-tightness index does not have significant distinct characteristics due to the train passing through differences length tunnels.
CRH5A EMUtunnel pressure wavetrain aerodynamic loadinternal pressure comfortdynamic air-tightness indexvehicle field test