Flow and sound fields of scaled high-speed trains with different coach numbers running in long tunnel

作     者：Qiliang Li Yuqing Sun Menghan Ouyang Zhigang Yang 

作者机构：School of Automotive StudiesTongji UniversityShanghai 201804China Shanghai Automotive Wind Tunnel CenterTongji UniversityShanghai 201804China School of Aerospace Engineering and Applied MechanicsTongji UniversityShanghai 200092China 

出 版 物：《Railway Engineering Science》 (铁道工程科学（英文版）)

年 卷 期：2024年第32卷第3期

页      面：401-420页

学科分类：0202[经济学-应用经济学] 02[经济学] 020205[经济学-产业经济学] 0823[工学-交通运输工程] 

基　　金：supported by the National Natural Science Foundation of China (Grant No. 52072267) Shanghai Key Lab of Vehicle Aerodynamics and Vehicle Thermal Management Systems (Grant No. 23DZ2229029) 

主　　题：Flow and sound fields Scaled high-speed trains Different coach numbers Long tunnel Proper orthogonal decomposition 

摘      要：Segregated incompressible large eddy simulation and acoustic perturbation equations were used to obtain the flow field and sound field of 1:25 scale trains with three,six and eight coaches in a long tunnel,and the aerodynamic results were verified by wind tunnel test with the same scale two-coach train ***-averaged drag coefficients of the head coach of three trains are similar,but at the tail coach of the multi-group trains it is much larger than that of the three-coach *** eight-coach train presents the largest increment from the head coach to the tail coach in the standard deviation(STD)of aerodynamic force coefficients:0.0110 for drag coefficient(Cd),0.0198 for lift coefficient(Cl)and 0.0371 for side coef-ficient(Cs).Total sound pressure level at the bottom of multi-group trains presents a significant streamwise increase,which is different from the three-coach *** walls affect the acoustic distribution at the bottom,only after the coach number reaches a certain value,and the streamwise increase in the sound pressure fluctuation of multi-group trains is strengthened by coach *** transform of the turbulent and sound pressures presents that coach number has little influence on the peak frequencies,but increases the sound pressure level values at the tail bogie ***,different from the turbulent pressure,the first two sound pressure proper orthogonal decomposition(POD)modes in the bogie cavities contain 90%of the total energy,and the spatial distributions indicate that the acoustic distributions in the head and tail bogies are not related to coach number.