高速列车气动性能的尺度效应分析

采用数值模拟方法，研究高速列车在不同运行工况（明线运行、明线交会、隧道通过以及隧道交会）下的尺度效应，探析模型缩比对列车气动力及表面压力的影响规律.结果表明：模型缩比越小，头车及整车的阻力系数越大，升力系数越小.对于单车过隧道以及隧道内交会，模型缩比的变化不影响车体表面测点的压力幅值在车体长度方向的分布特性.当列车全尺寸交会时，车体表面压力变化幅值最小.在不同运行工况下，当模型缩比为1/20时，车体壁面的压力变化幅值最大，相对全尺寸工况，幅值增加最多可达6%.研究结果可为将列车小尺度模型缩比试验外推到全尺寸时的数据修正提供理论依据，同时为模型缩比的风洞试验以及动模型试验的方案设计提供指导.
Abstract: Calculation simulation was used to explore the scale effect in the aerodynamic performance of high-speed train under various working conditions (trains on open track, passing each other on open track, through a tunnel and passing each other in tunnel). Results show that, with decreasing model scale, the drag coefficient of the head and the whole train decreases, while the lift coefficient increases. For a single train passing through a tunnel and two trains passing each other in tunnel, the model scale does not change the surface pressure distribution properties along the train's longitudinal direction. When the train passing each other in full size, the pressure change amplitude of train surface is minimum. Under different working conditions, when the model scale is 1/20, the pressure change amplitude of wall surface is maxinmum; the increase of amplitude is up to 6%, compared with full-scale working condition. The experimental results can provide guidance for program design of data correction, wind tunnel test and moving model test when the test results of scaled models are extrapolated to the full-scale condition.