跌扩式消力池临底流速及水流流态分析

Analysis on Near-bottom Flow Velocity and Flow Regime of Drop-Expansion Stilling Basin

摘要:

基于模型试验和数值模拟,研究了一定水力条件、突扩比分别为1.0、1.3、1.6的跌坎消力池内临底流速分布规律及水流流态。结果表明:突扩使跌坎消力池内各纵断面临底流速分布发生较大变化,出现流速分层现象。不同突扩比对各纵断面上最大临底流速的影响有所不同,中线上的临底流速因突扩的存在而降低,中线两侧的临底流速随突扩比的增大而增大。临边墙处的最大临底流速因突扩的存在而大大降低,且随突扩比的增大而持续降低,但降低幅度随突扩比的增大而明显减小。研究成果可为跌扩式消力池设计及运行提供参考。

Abstract:

Based on model tests and numerical simulation, this paper discusses the investigation of the distribution law of near-bottom flow velocity and flow regime in the drop-expansion stilling basin under certain hydraulic conditions with sudden expansion ratios of 1.0, 1.3 and 1.6. The results indicate that sudden expansion greatly changes the distribution of near-bottom flow velocity at each longitudinal section of the drop-expansion stilling basin and causes flow velocity stratification. The influence of different sudden expansion ratios on the maximum near-bottom flow velocity of each longitudinal section varies. The near-bottom flow velocity on the center line decreases due to sudden expansion. The near-bottom flow velocity on both sides of the center line increases with the growth of sudden expansion ratio. The maximum near-bottom flow velocity near the side wall is greatly reduced by sudden expansion and continues to decline with the increase of sudden expansion ratio, whereas the reduction range decreases obviously. The research results can provide a reference for the design and operation of drop-expansion stilling basins.