高速列车受电弓上下臂杆气动降噪大涡模拟研究OA北大核心CSTPCD

As an important current receiving device exposed on the top of a high-speed train,the pantograph radiates aerodynamic noise and thus has become one of the main noise sources of high-speed trains.In order to suppress the aerodynamic noise radiated from pantograph and its components,large eddy simulation(LES)of air flow was carried out around a simplified on-roof-pantograph via replacing original circular cross-section straight rods of the upper and lower arms with elliptical cross-section straight rods and elliptical cross-section longitudinal torsion rods,respectively,combined with the sound analogues of Ffowcs Williams and Hawkings(FW-H).The flow characteristics and aerodynamic noise radiation were analyzed to study the effect of the new type of pantograph arms on the flow and the aerodynamic noise characteristics in the near and far fields.The results show that the aerodynamic noise in the near and far fields radiated by pantographs with elliptical cross-section longitudinal torsion arms appears to be weaker at different speeds of high-speed train,implying some kind of noise reduction effect.Specifically,when the speed is 300 km/h,the peak of sound pressure level at 25 m in the far field can be reduced by about 4.3 dB(A),or about 4.4%.When the speed is 400 km/h,the peak of sound pressure level at 7.5 m in the near field can be reduced by about 5 dB(A),or about 5.5%.