二级沙波水流特性的大涡模拟  

Large-eddy simulation of flow characteristics over secondary dunes

作　　者：董伟良[1] 诸裕良[1] 马殿光[2] 徐俊锋[2] 

机构地区：[1]河海大学港口海岸与近海工程学院,南京210098 [2]交通运输部天津水运工程科学研究所,天津300456

出　　处：《水道港口》2016年第2期154-158,共5页Journal of Waterway and Harbor

基　　金：中央级公益性科研院所基本科研业务费专项资金项目(TKS150102;TKS130105)

摘　　要：采用FLuent软件平台大涡模拟方法(LES)对二级沙波水流特性进行数值模拟,进出口边界采用周期性条件以模拟一系列沙波。通过与水槽试验数据对比发现,模拟计算结果与试验数据吻合较好,在此基础上对3种不同水平位置处的二级沙波进行模拟。计算结果表明:当二级沙波距一级沙波波峰较远时,二级沙波对一级沙波起遮掩作用,使得一级沙波回流区范围减小,垂向负流速区更加接近一级沙波波峰,同时二级沙波背流面的水流会对一级沙波迎流面形成侵蚀,进而减小一级沙波尺度;当一、二级沙波接近融合或融合时,两者之间的非线性相互作用使得回流区范围扩大,紊动增强。Q准则等值面显示,二次沙波的叠加增强了沙波涡旋结构的尺度和强度。Based on the Fluent software, the large eddy simulation（LES） technique was used to model the flowcharacteristics over secondary dunes. Periodic boundary condition was imposed at the inlet and outlet to simulate aseries of dunes. Good agreement was obtained between the simulation and experimental data, and secondary dunesat three different positions were simulated. The results show that the secondary dune has a shelter effect on the pri-mary dune when far from the crest of the primary dune, which reduces the range of recirculation zone and makes ver-tical negative velocity zone more close to the primary dune crest. Additionally, the current at the lee side of second-ary dunes can cause erosion at the upstream side of the primary dune, thus diminish the dimension of the primarydunes. However, recirculation zone becomes large and turbulence intensities increase due to nonlinear interactionbetween current and dunes when secondary dunes approach and merge with the primary dune. The size and strengthof vortex structures, visualized by the isosurface of Q-criterion, were strengthened by the secondary dune.

关 键 词：二级沙波 大涡模拟 水平位置 Q准则 

分 类 号：TV135[水利工程—水力学及河流动力学] O35[理学—流体力学]