黄河下游滩区村台绕流特性研究

Characteristic Research on Flow around Village Platform in the Downstream Yellow River Bottomland

黄河下游滩区村台是滩区居民常用的避洪工程结构形式,不同的矩形村台结构、村台辅道布置及辅道坡度,在不同夹角洪水作用下村台周围流场的特性差异很大.本文采用数值模拟方法,对不同方向来水、长宽比、村台辅道布置及辅道坡度作用下的滩区村台三维绕流特性,进行了数值模拟研究;揭示了村台来流方向角、长宽比、村台辅道布置及辅道坡度对村台周围绕流特性的影响;研究发现:当村台长宽比K<1时,来流方向角α=0°时,村台阻力较大;而当村台长宽比K>1时,来流方向角α=0°时,村台阻力最小;村台建设的最佳长宽比为1.5—2.0;相同的辅道坡度下,垂直来流方向时村台的时均阻力明显大于平行于来流方向时村台的时均阻力;村台最佳辅道坡度为1∶10—1∶15.

Village platform is an important structure to avoid flooding for residents in the downstream Yellow River bottomland.Characteristics of flow field around village platform with different rectangle structures,auxiliary road locations and road slopes vary a lot under the effects of various flow angles.Numerical simulation was carried out on three dimensional flow patterns around village platform under the effects of different inflow directions,platform aspect ratios,auxiliary road locations and road slopes.The influence of the inflow angle,aspect ratio,auxiliary road location and road slope on flow characteristics around village platform was discovered.Research conclusions include：the village platform resistance is big when the platform aspect ratio is less than 1 and the inflow angle is 0°;the village platform resistance is the smallest when the platform aspect ratio is greater than 1 and the inflow angle is 0°;the optimal platform aspect ratio is 1.5—2.0;time averaged resistance of platform when vertical to the inflow is greater than that when parallel to the inflow under the same auxiliary road slope;the optimal platform auxiliary road slope is 1∶10—1∶15.