软体排模型垂直水流铺排水流时均特性研究

Experimental analysis for laying of flexible mattresses quasi-perpendicular to flow direction

针对水深或流速较大时软体排沉排一直存在浮排、撕排等现象,为了解不同方位放置软体排的水流结构特性,采用透明的有机玻璃板模拟铺排船钢滑板和排布,利用高分辨率PIV对排布区域进行二维流速测量。分析垂直水流铺排时平水、迎水和逆水等3个方案的水面线、平均速度、紊流度等变化特性。结果表明:迎水铺排时,排头易形成滑排与撕排;逆水铺排时,水流顶托软体排易形成浮排;平水铺排时,水流条件最有利于软体排下沉。研究为进一步解决深水沉排问题提供了理论依据。

The revetments ,such as flexible mattresses ,in the long‐term riverbank and riverbed protection are commonly used . When in the larger velocity and water depth ,however ,the associated failure mechanisms of flexible mattresses ,tearing and float‐ing mattress are still not well understood yet .To enhance the fundamental understanding of the performance of flow among the pensile mattress at diffident direction placed ,a laboratory experimental program was undertaken using high‐resolution particle im‐age velocimetry (PIV) to measure the 2‐D velocity field of mimetic mattress ,where transparent organic glass was used to repre‐sent the flexible mattress .The characteristics of water surface profiles ,mean velocity profiles and turbulence intensity were ana‐lyzed ,on the condition that geotextiles laying direction was quasi‐perpendicular to the flow .The results indicated that slipping and tearing can easily occur for the beginning mattress and floating can easily occur for the middle mattress ,when the upper sur‐face respectively faced and was back to the flow .Besides ,when the upper surface was parallel to the flow ,it was of the best ad‐vantage for the sinking of flexible mattress .The results provided a theoretical basis for solving the sinking for flexible mattress in deep w ater .