文章摘要
黄海,张红武,张磊,钟德钰.水沙两相浑水模型的紊流封闭及初步验证[J].水利学报,2020,51(1):69-80
水沙两相浑水模型的紊流封闭及初步验证
A two-phase mixture turbulence model for sediment-laden flows:theory and verification
投稿时间:2019-02-04  
DOI:10.13243/j.cnki.slxb.20190086
中文关键词: 紊流  固液两相浑水紊流模型  悬移质泥沙
英文关键词: turbulence  two-phase mixture turbulence model  suspended load
基金项目:国家自然科学基金项目(91547204,51379102,51609264);国家重点研发计划项目(2016YFC04022500,2017YFC0404303)
作者单位E-mail
黄海 清华大学 水沙科学与水利水电工程国家重点实验室, 北京 100084  
张红武 清华大学 水沙科学与水利水电工程国家重点实验室, 北京 100084  
张磊 中国水利水电科学研究院 泥沙研究所, 北京 100048  
钟德钰 清华大学 水沙科学与水利水电工程国家重点实验室, 北京 100084
青海大学 三江源生态与高原农牧业国家重点实验室, 青海 西宁 810016 
zhongdy@tsinghua.edu.cn 
摘要点击次数: 139
全文下载次数: 96
中文摘要:
      一些学者采用两相浑水模型模拟挟沙水流运动,但其紊流封闭仍借用经验公式、单相紊流模型或双流体紊流模型,未形成两相浑水理论框架下的紊流模式。本文基于双流体紊流模型推导出固液两相浑水紊动能和紊动耗散的偏微分方程,给出固相偏移紊动能的渐近解,以表示固相紊动能与固液两相浑水紊动能的相对差,继而推导出固相紊动耗散的代数表达式,完成对固液两相浑水模型的紊流封闭。固液两相浑水紊流模型能够考虑相间作用和颗粒碰撞等物理机制,保留了双流体紊流模型能够分别计算固、液相各自紊动信息的特点,又将偏微分方程数量减少一半。采用河流动力学绝对含沙量分布的计算方法,并引入各向紊动强度分配系数进行修正后,利用实验资料对两相浑水紊流模型进行验证,计算结果同实测值符合较好,结果表明本文模型能反映出随着泥沙浓度增加,挟沙水流紊动抑制加剧的现象。
英文摘要:
      Two-phase mixture models are used to reproduce the motion of sediment-laden flows. Empirical constitutive relations,modified single-phase k-ε models and two-fluid turbulence models are usually applied to close two-phase mixture models. However, the turbulence model under the framework of the two-phase mixture theory has not been formed yet. In this paper, a two-phase mixture turbulence model was derived based on a two-fluid turbulence model. The equations of turbulent kinetic energy and turbulent dissipation rate of solid-liquid mixtures were derived. A key variable,the dispersion turbulent kinetic energy,defined as the mean relative turbulent kinetic energy of sediment to that of mixtures,is introduced to close the two-phase mixture turbulence model. An algebraic expression of the turbulent dissipation rate of solid phase is proposed. The two-phase mixture turbulence model takes into account interphase interaction and particle collisions,inherits the capabilities of the two-fluid turbulence model to predict turbulent information of both phases separately,and reduces the number of partial differential equations in half. The function of the absolute concentration distribution was adopted to determine the bottom boundary condition of sediment concentration. The partition coefficient of turbulent intensity in each direction was introduced to consider the turbulent anisotropy. A set of experiments were selected to verify the two-phase mixture model closed by the turbulence model acquired in this paper. The results are in satisfactory agreements with the observations. In addition,the experimental observations that the turbulent intensity decreases with the increment of sediment concentration can be reproduced by this model.
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