开口式风洞高速列车头车气动实验模型选取方法

Selection of Head Car Model for High Speed Train in Open-section Wind Tunnel Test

摘要:

合理的风洞高速列车实验模型对其气动评估和研究十分重要。采用计算流体力学方法，以开口式风洞和高速列车头车为对象，研究风洞实验头车最短尾部模型和合理缩比模型的选取方法。结果表明：无侧风时头车阻力系数随着尾部模型缩短而增加，尾部负压前移使得车厢连接处压力降低，头车+0.4L尾部模型的头车阻力与3车编组头车偏差为2.8%，可作为头车气动最短实验模型。头车最大缩比模型选取受风洞边界效应、雷诺数效应和地面效应共同影响，其中雷诺数效应使得摩擦阻力减小，地面效应使压差阻力增大，1：8、1：4缩比模型与1：1模型头车的压差阻力偏差为12.7%和7.2%，压差阻力分别占头车总阻力63.9%、67.2%和72.5%。结果表明，对于开口式风洞选取1：4的头车气动实验模型更为合理。

Abstract:

Reasonable scaled model of high-speed train is very important for aerodynamic evaluation and research in wind tunnel. Based on the computational fluid dynamics method， the selection method of the shortest tail model and the reasonable scale model of the head car in wind tunnel test was studied. The results reveals that： the drag coefficient of the head car increases with the shortening of the tail model， and the negative pressure of the tail moves upstream， which reduces the pressure at the inter-coach space. The deviation between the drag of the head car +0.4L tail model and that of the three cars model is 2.8%， which can be used as the shortest model of the head car. The selection of the scale model of the head car is affected by the wind tunnel boundary effect， Reynolds number effect and ground effect. The Reynolds number effect reduces the frictional drag， while the ground effect increase the pressure drag. The 1：8， 1：4 scale model and full-scale model's head car pressure drag deviation are 12.7% and 7.2%， which account for 63.9%， 67.2% and 72.5% of the head car's total drag respectively. The result shows that， it’s more reasonable to choose the 1：4 scale model as high-speed train experiment model in open-section wind tunnel.