Influence of ribs on train aerodynamic performances  

作　　者：苗秀娟 高广军 

机构地区：[1]College of Automobile and Machinery Engineering, Changsha University of Science and Technology [2]Key Laboratory of Traffic Safety on the Track of Ministry of Education (Central South University)

出　　处：《Journal of Central South University》2015年第5期1986-1993,共8页中南大学学报（英文版）

基　　金：Projects(51075401,U1134203,U1334205)supported by the National Natural Science Foundation of China;Project(NCET-10-083)supported by the Program for New Century Excellent Talents in University of Ministry of Education,China;Project(2013J004-8)supported by the Science and Technology Research and Development Program of China Railway Corporation

摘　　要：The influence of ribs on the train aerodynamic performance was computed using detached eddy simulation(DES), and the transient iteration was solved by the dual-time step lower-upper symmetric Gauss-Seidel(LU-SGS) method. The results show that the ribs installed on the roof have a great effect on the train aerodynamic performance. Compared with trains without ribs, the lift force coefficient of the train with convex ribs changes from negative to positive, while the side force coefficient increases by 110%and 88%, respectively. Due to the combined effect of the lift force and side force, the overturning moment of the train with convex ribs and cutting ribs increases by 140% and 106%, respectively. There is larger negative pressure on the roof of the train without ribs than that with ribs. The ribs on the train would disturb the flow structure and contribute to the air separation, so the separation starts from the roof, while there is no air separation on the roof of the train without ribs. The ribs can also slow down the flow speed above the roof and make the air easily sucked back to the train surface. The vortices at the leeward side of the train without ribs are small and messy compared with those of the train with convex or cutting ribs.The influence of ribs on the train aerodynamic performance was computed using detached eddy simulation（DES）, and the transient iteration was solved by the dual-time step lower-upper symmetric Gauss-Seidel（LU-SGS） method. The results show that the ribs installed on the roof have a great effect on the train aerodynamic performance. Compared with trains without ribs, the lift force coefficient of the train with convex ribs changes from negative to positive, while the side force coefficient increases by 110%and 88%, respectively. Due to the combined effect of the lift force and side force, the overturning moment of the train with convex ribs and cutting ribs increases by 140% and 106%, respectively. There is larger negative pressure on the roof of the train without ribs than that with ribs. The ribs on the train would disturb the flow structure and contribute to the air separation, so the separation starts from the roof, while there is no air separation on the roof of the train without ribs. The ribs can also slow down the flow speed above the roof and make the air easily sucked back to the train surface. The vortices at the leeward side of the train without ribs are small and messy compared with those of the train with convex or cutting ribs.

关 键 词：TRAIN RIB detached eddy simulation(DES) aerodynamic performance CROSSWIND 

分 类 号：U270.1[机械工程—车辆工程]