基于泥沙异重流稳定性与衰减过程的床面淤积特性研究  

Study on bed deposition characteristics based on the stability and decay processes of sediment density current

作　　者：温志超 石林平 黄哲[4] 白玉川[4] WEN Zhi-chao;SHI Lin-ping;HUANG Zhe;BAI Yu-chuan(Yellow River Engineering Consuling Corporation,Zhengzhou 450003,China;Key Laboratory of Water Management and Water Security for Yellow River Basin,Ministry of Water Resources(Under Construction),Zhengzhou 450003,China;Shenzhen East Water Resources Management Center,Shenzhen 518000,China;State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin300350,China)

机构地区：[1]黄河勘测规划设计研究院有限公司,河南郑州450003 [2]水利部黄河流域水治理与水安全重点实验室(筹),河南郑州450003 [3]深圳市东部水源管理中心,广东深圳1518000 [4]天津大学水利工程安全与仿真国家重点实验室,天津300350

出　　处：《泥沙研究》2024年第3期33-40,32,共9页Journal of Sediment Research

基　　金：国家自然科学基金项目(52109097,U22A20237)。

摘　　要：泥沙异重流在稳定分层和不断衰减的过程中,伴随着床面淤积特征的变化。通过水槽试验观测异重流“稳定-衰减”过程,结合异重分层流运动理论模型,探究该过程对床面淤积特征的影响。研究结果表明,增加异重流层密度或厚度,形成稳定分层形态的时间明显缩短,同时延长了分层形态的维持时间;计算得到的临界雷诺数与扰动波数虚部相应增加,分层形态稳定性得以增强。异重流的稳定行进对于减小床面淤积具有重要作用,试验中临界雷诺数增加568~820,平均淤积厚度降低了42%~46%。因此,提高异重流稳定性并延缓衰减速率,有助于提高输沙率,可以达到减淤的目的。During the process of the stable stratification and continuous attenuation of sediment density current, it is accompanied by changes in the characteristics of sediment deposition on the bed. Based on the observed process of stable stratification and attenuation of density current in the flume experiment, and combining with the theoretical model of sediment density current movement the influence of the “stability-attenuation” process of density current on the bed deposition has been explored. Research results show that: with the increase of the density or thickness of lower density current, the formation time of stable stratification of density current is significantly shortened, and the maintenance time of stratification is prolonged. Thetheoretical results also show that the critical Reynolds Re_(cr) and the imaginary part of the disturbance wave number α_i increase under these conditions, which indicates that the stability of stratification is enhanced and the stabe movement of density current plays an important role in reducing bed deposition. In the experiment, the critical Reynolds number Re_(cr) increased by 568~820, the average deposition thickness decreased by 42%~46%. Therefore, improving the stability of density flow and delaying the deceleration rate can help improve the sediment transport rate and achieve the goal of reducing sediment deposition.

关 键 词：泥沙异重流 分层流稳定性 扰动增长率 衰减过程 淤积 

分 类 号：TV145.2[水利工程—水力学及河流动力学]