横流环境下振荡射流初始稀释规律  

Initial dilution characteristics of an oscillating jet in cross-flow environment

作　　者：徐振山[1] 黄振超 李蒙 陈永平[1] 张长宽[1] XU Zhenshan;HUANG Zhenchao;LI Meng;CHEN Yongping;ZHANG Changkuan(College of Harbor,Coastal and Offshore Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学港口海岸与近海工程学院,江苏南京210098

出　　处：《水科学进展》2022年第6期1000-1008,共9页Advances in Water Science

基　　金：国家自然科学基金资助项目(51979076)。

摘　　要：横流环境下振荡射流的运动和稀释特性研究对于提高排放工程稀释能力非常重要。利用三维大涡数学模型研究了横流环境下振荡射流的初始稀释规律,探讨了各参数对射流稀释效果的影响;通过引入射流特征速度与特征长度并进行量纲分析,得到了横流环境下振荡射流的断面最小稀释度和可视范围面积经验公式,并将其与波流环境下非振荡射流的稀释规律进行对比。研究表明:横流环境下振荡射流下游断面浓度极大值出现在反向对称漩涡(CVP)结构位置或“污染物云团”位置;振幅-射流速度比越大,最小稀释度越大,断面可视范围面积越大;随着斯特劳哈尔数的减小,断面可视范围面积增加,最小稀释度变化不明显;横流环境下振荡射流和波流环境下非振荡射流的初始稀释经验公式结构一致,射流振荡性产生的初始稀释促进作用与波浪效果类似。Study on the motion and dilution of oscillating jet in cross-flow environment is of great importance for sewage discharge engineering.The initial dilution characteristics of an oscillating jet in cross-flow environment were investigated using a three-dimensional large eddy simulation model.The impact of each jet parameter on the initial dilution effect of the jet was discussed.The empirical formula of minimum dilution and the visible area of oscillating jet were identified through dimensional analysis with characteristic velocity and characteristic length.The comparison between the oscillating jet in cross-flow environment and the non-oscillating jet in wave-current environment was also addressed in the study.It suggests that the maximum concentration on the downstream section of the oscillating jet in cross-flow environment occurs either at the position of the counter-rotating vortex pair(CVP)or the“effluent cloud”.The larger the oscillating amplitude ratio R_(aj),the larger the minimum dilution and the visible area;as S_(t) decreases,the visible area increases while the minimum dilution does not change significantly.The empirical formula for initial dilution of the oscillating jet in cross-flow environment have the same structure with those of non-oscillating jet in the wave-current environment,and the initial dilution promotion induced by jet oscillation is similar to the wave effect.

关 键 词：横流环境 振荡射流 初始稀释 经验公式 

分 类 号：TV132.1[水利工程—水力学及河流动力学]