刚性淹没双层植被明渠水流紊流特性研究  

Turbulence Structure of Open Channel Flow Through Double Layer Rigid Submerged Vegetation

作　　者：王雯[1] 槐文信[1] 

机构地区：[1]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072

出　　处：《四川大学学报（工程科学版）》2014年第1期61-67,共7页Journal of Sichuan University (Engineering Science Edition)

基　　金：国家自然科学基金资助项目(51079102;11372232);高等学校博士点基金资助项目(20130141110016)

摘　　要：采用标准k-ε紊流模型,结合雷诺平均Navier-Stokes方程,对刚性淹没双层植被明渠水流特性进行研究。计算所得的流速值与实测值吻合良好,表明计算方法可行。进而根据空间及时间的双平均理论,给出了双平均条件下的明渠流速、雷诺应力及紊动能分布,并对紊动能平衡方程中的各项进行了分析。结果可以看出,刚性双层淹没植被作用下,垂向流速分布曲线由3个拐点将其划分为4个区域;雷诺应力及紊动能分布在植被顶端明显增强,高植被顶端各项值均大于低植被顶端相应值;紊动能平衡方程中的紊动耗散项及压力耗散项在紊动能平衡方程中起着主导作用;植被顶端区域产生的涡,通过喷射和扫掠作用使其附近水体发生质量及动量交换。Standard turbulence model, combined with Reynolds-averaged Navier-Stokes （RANS） equations,was used to study the turbu- lence structure of open channel flow through double layer rigid submerged vegetation. The calculated velocity distributions are in good a- greement with test data,which proves the validity of the computational method. The velocity distribution, Reynolds stress, and turbulent energy distribution were derived by using the double-averaged（ in space and in time） hydrodynamic equations. The vertical velocity dis- tribution was divided into four regions by three turning points. The results showed that Reynolds stress and turbulent energy distribution dramatic increases at each top of the vegetation layer, and maximum value can be found near the taller vegetation. Turbulent dissipation and pressure dissipation play a leading role in the balance of turbulent energy equation. The vortex that generated at the top of vegetation results in a massive mass and momentum transfer through ejection and sweeps.

关 键 词：明渠流 植被 紊流模型 紊动能 双平均理论 紊动能平衡 

分 类 号：TV133.1[水利工程—水力学及河流动力学]