高寒动车组槽型引流式结构的防积雪性能研究

Research on anti-snow performance of diversion-slot structure in bogie regions of alpine EMU

为了解决高寒动车组车载防转向架区域积雪难题,采用基于Realizable k−ε湍流模型的非定常雷诺时均方法(URANS)和离散相模型(DPM)研究槽型引流结构对高寒高速列车转向架区域风雪运动特性的影响。研究结果表明:高寒动车组安装槽型引流结构可促使车底剪切层提前分离,从而大幅度降低转向架区域内的风雪流向运动速度,并抑制转向架区域内风雪垂向速度的波动幅值,进而有效缓解转向架区域的积雪情况。相比于5.14°导流槽结构,10°导流槽结构明显改变了转向架入口位置的风雪流运动方向,进而有效降低了转向架下方风雪流的垂向分布范围,削弱了车底高速气流和高浓度雪粒对转向架发热部件迎风面的冲击作用;10°导流槽结构还显著抑制了风雪流在转向架中间区域和后端板位置的向上爬升运动,降低了转向架上方悬浮雪粒数量,进而减小了转向架上表面积雪分布;相比于原始高寒动车组,5.14°和10°槽型引流防积雪结构可使所有转向架积雪总质量分别降低19.6%和28.3%。

To solve the problematic issue of train-borne anti-snow technology around the bogie regions of the alpine electric multiple unit(EMU),the effects of the diversion-slot anti-snow structure on the snow accumulation in the bogie region of the alpine EMU were investigated using unsteady Reynolds-Averaged Navier-Stokes simulations(URANS)based on Realizable k−εturbulence model coupled with the discrete phase model(DPM).The results show that the installation of diversion slots can facilitate the separation of shear layers in advance,effectively decrease the stream-wise speed of wind-snow flow,weaken the fluctuation amplitude of the vertical velocity of the wind-snow flow beneath the bogies,and thereby relieve the snow accumulation issue in the bogie regions.Compared to the case with the installation of the 5.14°guide slots,the 10°diversion slots significantly change the moving direction of the wind-snow flow at the entrance of the bogie and compress the vertical distribution range of the wind-snow flow in the bogie region,which effectively weakens the strong impingement on the windward surfaces of the primary heat-producing components caused by the high-speed airflow and highconcentration snow.The 10°diversion slots also significantly inhibit the upward climbing movement of air flow in the vicinity of the middle bogie area and rear end plates,and therefore reduce the amount of the suspending snow particles over the bogies and decrease the snow accretion on the bogies'top surface.Compared with the original Alpine EMU,the 5.14°and 10°diversion-slot anti-snow structures can reduce the total snow mass accumulating on all bogies of the alpine EMU by 19.6%and 28.3%,respectively.