列车交会篷布气动力分析

Crossing aerodynamic force analysis of tarpaulin for trains

为解决目前一车苫盖2张货车篷布(简称X型篷布)存在的严重兜风现象与货物湿损问题,并检验新型篷布(简称D型篷布)的使用效果,基于不同装载与加固方案,通过实车试验,针对D型篷布与X型篷布在有绳网和无绳网12种情况下,测试了列车交会压力波和货车蓬布绳索拉力。测试结果表明:当80～120km·h-1速度下的货车与200～210km·h-1速度下的动车组交会时,动车组上感受的最大压力波幅值仅为577Pa,货车感受到的最大压力波幅值为715Pa;绳索最大值为1055N,出现在无网X型篷布的角绳上,满足相关规定要求;没有苫盖篷布绳网时,2种篷布兜风现象均较严重,同等速度下无绳网X型篷布逆向压缝篷布绳索拉力比顺向压缝的大40%左右;篷布绳网在降低篷布绳索气动力中发挥了重要作用,大部分工况下无绳网篷布绳索受到的气动力比有网的大50%～80%。可见,在相同工况下,D型篷布比X型篷布使用性能优良。

In order to solve catching wind badly and goods being soaked and damaged easily for two-piece freight tarpaulin（X-type tarpaulin）, and to test the using effect of new freight tarpaulin （Dtype tarpaulin）, defferent loading and reinforcing projects were considered, twelve using conditions with and without cord net were confirmed, the crossing pressure waves of trains and the tensile forces of tarpaulin cord and net cord were tested by full-scale train test. The result shows that when freight car at 80-120 km · h^-1 passes by multiple unites at 200-210 km · h^-1 , the maximal magnitudes of air pressure waves are 577 Pa and 715 Pa separately for multiple unites and freight car; the maximal tensile force of cord is 1 055 N, and it appears at the corner cord of X-type tarpaulin without net, which satisfies the demand of correlative standards; catching wind of two kinds of tarpaulins without net is seriously, and at the same speed, the tensile force of X- type tarpaulin against wind is about 40 % greater than that down wind; cord net has an important role, and the tensile force of cord without net is 50%-80% greater than that with net. Thus, D- type tarpaulin has better using performance than X-type tarpaulin under the same instance. 4 tabs, 7 figs, 9 refs.