波流环境中污染物混合的分析  

Analysis on the mixing of pollutants in water current combining with waves

作　　者：袁丽蓉[1] 沈永明[2] 唐军[2] 

机构地区：[1]中山大学广东省近岸海洋工程重点实验室,广东广州510275 [2]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116023

出　　处：《水利学报》2007年第3期260-266,共7页Journal of Hydraulic Engineering

基　　金：国家自然科学基金项目(50579005);国家自然科学基金重点项目(10332050);国家重点基础研究发展计划(973)项目(2005CB724202)

摘　　要：本文根据垂向二维数值模型计算求解和分析了波流环境中的一维对流扩散方程中的混合系数。此二维数值模型采用非线性k-ε紊流模型封闭雷诺时均方程,应用VOF方法处理自由面。分析方法是用该二维模型计算波流环境中污染物瞬时源产生的浓度场,计算该浓度场的断面平均浓度,求此断面平均浓度的概率分布,由概率分布的方差随时间的导数得到一维对流扩散问题中的混合系数。通过算例分析,发现波流环境混合系数随着波浪周期和波高的不同,可能大于纯流和纯波的混合系数之和,也可能比纯流情况下小;波周期与混合系数呈正比。且存在一个使混合系数最大的波高。The nonlinear κ-ε turbulence model and VOF method is combined to numerically solve the vertical 2-D time average equation for pollution transportation. By using this method the spatial distribution and temporal variation of velocity field, diffusion coefficient and pollution concentration distribution due to waves, current or the combination of wave and current can be solved. The probability distribution of average pollutant concentration in cross section under the condition of current combining with waves is calculated based on the instant distribution of pollutants. The mixing coefficient for 1-D calculation is deduced from the derivative of variance of probability distribution. The calculation example shows that under the condition of current combining with waves the mixing coefficient varies with the period and height of waves and will larger than the sum of the mixing coefficients corresponding to the cases only current flow or only waves is existed. The mixing coefficient is positively proportion to wave period and a maximum related to wave height may exist.

关 键 词：混合 波流 紊流模型 VOF方法 污染物浓度 

分 类 号：X143[环境科学与工程—环境科学] TV131[水利工程—水力学及河流动力学]