侧风环境下行驶的直背式轿车气动力计算.pdfVIP

22 11 Vol. 22 No . 11 2007 11 Journal of Aerospace Power Nov . 2007 : 1000-8055 2007 11-1858-05 郑 昊, 康 宁, 蓝 天 , 100083 : , . , , ; , . , , . , , . : ; ; ; : U461. 1 : A Calculation of aerodynamic forces of a car with the eff ect of crosswind ZH ENG H ao, KA NG Ni g, LAN Tia Departme t of Automotive E gi eeri g, Beiji g U iversity of Aero autics a d Astro autics, Beiji g 100083, Chi a Abstract: The outflow field of a simplified fast back car w as simulated umerically w ith the effect of o cross w i d, steady cross w i d a d u steady cross w i d. The aerody amic forces a d coefficie ts were calculated. T he results show that, steady crossw i d w ill ge er- ate bigger lateral force, a d also i crease the drag a d lifti g force to a certai exte t; the cha ge tre d of aerody amic forces w as the same as that of lateral w i d speed. With the effect of u steady cross w i d, the drag i creases more slightly, a d the lateral force i crea- ses most sig ifica tly; the lifti g force remai s moderately . Whe cross w i d reaches a high level, the flow field w ill cha ge dramatically, a d the w ake vortex is tur ed i to side vortex . Key words: automobile aerody amics; aerody amic forces; crossw i d; u steady flow , . . 1 , , [ 1] . , 1. 1 , , 200 km/ h, . , 0. 3 , . . , CFD Flue t , . N- , , S : 2006-10-26; : 2007-01-18 : 1982- ,, , , 11 : 1859 y # V 0 1 7 , 3 , 4 5V yp 2 , 4 , 20 + V # y V - + v y V 2 5t Q mm. , V , y , p , Q, T. , . , . , , . , Spalart-Allmaras 2 , v t Fig . 2 Computatio al domai , : 5 1 5 5v t , Qv tv i Gv + L+ Lt + i v j 5xj 5x R 5x , 2 5v t , 3. Cb2 Q - Yv 3 5xj . , Gv , Yv , Rv , . Cb2 . 70 . QU ICK , . [ 2] , , . [ 2] , , Spa-l art-Allmaras , QUICK . 1. 2 1. 512 mm, 138 mm, 206 mm, 3 , , , Fig . 3 Grid i t he lo gitudi al sectio of symmetry , . 1. 3 1. 3. 1 , 3 -5 1. 205 kg/ m , 1. 81 @ 10 kg/ m # s . , X v 35 m/ s. , 1 Y , u 5 m/ s, Fig. 1 Sim plified car model [ 3]