高速磁浮列车气动阻力性能数值模拟与参数化评估

基于粘性流体力学理论,按三维可压缩粘性流对具有流线型头部形状的TR08列车以及通过变化流线型头部纵剖面高度或流线型头部长度设计出的4种新头型列车的周围流场进行了数值模拟。为评估不同流线型头部外形的气动阻力性能,定义了表示其形状特征的整体长细比作为评估依据,综合考虑了流线型头部水平投影形状和纵向对称面投影形状对气动阻力性能的影响。通过对5种不同头型列车的模拟结果进行对比分析,得出了流线型头部外形对气动阻力性能影响的规律:随着流线型头部长度增加,气动阻力降低,而中间车阻力变化不大;在头部流线型长度相当的情况下,纵剖面轮廓线上凸的头车气动阻力比下凹的小,而尾车气动阻力大。计算得到的不同流线型列车的整体长细比大小排序与其气动阻力系数排序完全一致。分析结果表明,增加流线型头部长度是减小气动阻力的有效途径;整体长细比能较好地反映流线型头部对列车气动阻力性能的影响。

Numerical simulation and parameterized investigation of aerodynamic drag performances of high-speed maglev trains

The flow fields around streamlined high-speed maglev trains,including train TR08 and four new trains designed by changing the profile or length of longitudinal projection,were simulated with 3-D compressible viscous fluid theory.In order to evaluate the aerodynamic drag performances of different nose configurations,a non-dimensional parameter defined as total slenderness ratio,which indicated the configuration features,was brought forward as evaluating criterion,the influences of the horizontal and longitudinal projections of train streamlined noses on the drag performances were taken account.Simulation result shows that when other parameters are same,the aerodynamic drag decreases with the length increase of the streamlined nose,while the drag of middle car varies within a small range,when the length of streamlined nose is almost same,the aerodynamic drag of front car with protruding longitudinal profile is less than that of the concave,while that of the rear car is contrary.The order of total slenderness ratios of the five trains is as same as that of aerodynamic drag coefficients.Investigation result shows that increasing the length of streamlined nose is one of the effective ways to decrease train aerodynamic drag,and the total slenderness ratio can well reflect the streamlined configuration influence on train drag.2 tabs,13 figs,8 refs.