软体排沉排水流结构与排体动力特性数值模拟

Numerical simulation of flow structure and dynamic characteristics of sinking flexible mattress

针对软体排沉排施工时容易出现撕排和断排的问题,本文基于k-ωSST湍流模型,采用分区耦合算法对顺水沉排过程进行双向流固耦合模拟。分析了不同水流条件下绕流流场、涡流结构与排体动力特性,并结合室内水槽试验验证模型计算精度。结果表明:水流流经排体后发生流动分离,导致沿排宽中轴线形成对称的回流区。排体迎水面流速随水深增加呈指数型递增,排体后方高速尾流带的最大流速相较平均流速可增大40%~50%。当雷诺数增加,主体涡流结构由靠近床面侧逐步向水面处发展。此外,排体所受应力沿横向呈条带状分布,峰值集中于排体与翻板交界处及排头梁附近。研究结果可为完善排体结构设计、改进沉排施工工艺提供理论指导。

Inspired by the tearing and splitting of flexible mattresses during sinking construction,the k-ωSST tur-bulence model and partitioned coupling method were used to simulate the downstream sinking process in two-way coupling.The flow field around the flow,vortex structure,and dynamic response of the mattress were analyzed un-der different flow conditions,and the calculation accuracy of the model was validated through flume experiments.Results revealed that after the water flowed through the mattress,the flow separation occurred,resulting in a sym-metrical reflux zone along the central axis of the row width.The upstream surface velocity of the mattress increased exponentially with increasing water depth,and the maximum velocity in the high-speed wake zone behind the mat-tress was 40%~50%higher than the average velocity.As the Reynolds number increased,the main vortex struc-ture gradually developed from the side near the bed surface to the water surface.Moreover,stress on the mattress was distributed transversely as a strip,with peak stress concentration observed near the junction between the mat-tress,rotating plate,and head beam.This study provides theoretical guidance to improve the structural design of the mattress and techniques for sinking construction.