横流环境湍射流涡动力学特性数值模拟  

Numerical simulation of vorticity dynamics for turbulent jet in crossflow

作　　者：姜国强[1] 任秀文[1] 李炜[2] 

机构地区：[1]环境保护部华南环境科学研究所,广东广州510655 [2]武汉大学水利水电学院,湖北武汉430072

出　　处：《水科学进展》2010年第3期307-314,共8页Advances in Water Science

基　　金：国家自然科学基金资助项目(59979022)~~

摘　　要：采用三维湍流模型及其混合有限分析解法进行横流中湍射流这一复杂三维流动的研究。在利用实验数据对模型及其计算方法验证的基础上,对多种喷口形式和流速比工况下的流速场和涡量场进行了数值计算,模拟得到了其旋涡结构发展演化特性。在射流初始阶段,横流在射流背流面形成绕流分离旋涡,其结构与射流喷口形式和流速比有关。射流主轴沿流向布置的窄缝射流产生的旋涡最为特殊和复杂,在喷口侧面存在4个分离点,从而形成4个旋涡。在射流远区,流动主要由反向旋转涡对所控制,并诱导出二次涡对。分析得出了射流喷口形式及流速比对反向旋转涡对涡核位置和旋转强度的影响。A three dimension（3-D） numerical turbulent model is used to study the flow characteristics of turbulent jets in crossflow which is characterized as a complex 3-D flow.The turbulent model is solved using the hybrid finite-element-analytic method,and is tested through the experimental data.The turbulent model is then applied to simulating flow and vorticity fields with different diffuser forms and velocity ratios,and the formation and development of vortex structures in these flow conditions are obtained.During the initial stage of vortex formation,the crossflow detours the jet and forms the counter-rotating vortex on the lateral edges of jet.The subsequent vortex evolution depends very much upon the use of diffuser forms and the use of velocity ratios.The most complex vortex structure is found with the case of using slot diffuser.The latter has its major jet axis distributed along the streamwise.There are four separating points around the diffuser,and the separated flows gradually form four vortices.In the far zone,the jet flow is dominated by counter-rotating vortex pairs,which induce the formation of secondary vortex pairs in the near-wall region.The relation between the core position of counter-rotating vortex pairs and the velocity ratio for all types of diffuser forms is established,and so do for the rotating strength.

关 键 词：横流 湍射流 旋涡结构 水动力特性 数值模拟 

分 类 号：TV143[水利工程—水力学及河流动力学]