Secondary flow vortices and flow separation of 2-D turning diffuser via particle image velocimetry

International Research and Innovation Summit 2017

Nordin, N.^1 ; Seri, S.M.^1 ; Taib, I.^1 ; Mohammed, A.N.^1 ; Abdullah, M.K.^1 ; Sapit, A.^1

Flow Analysis, Simulation and Turbulence Research Group, Center for Energy and Industrial Environment Studies, Faculty of Mechanical and Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia, Johor, Malaysia^1

关键词: Core flow;    Flow charac-teristics;    Flow uniformity;    Flowthrough;    Inner walls;    Longitudinal section;    Particle image velocimetries;    Stereoscopic PIV;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/226/1/012149/pdf
DOI  :  10.1088/1757-899X/226/1/012149

来源: IOP

【 摘 要 】

It is often necessary in fluid flow systems to simultaneously decelerate and turn the flow. This can be achieved by employing turning diffusers in the fluid flow systems. The flow through a turning diffuser is complex, apparently due to the expansion and inflexion introduced along the direction of flow. In the present work, the flow characteristics of 2-D turning diffuser by means of varying inflow Reynolds number are investigated. The flow characteristics within the outlet cross-section and longitudinal section were examined respectively by the 3-D stereoscopic PIV and 2-D PIV. The flow uniformity is affected with the increase of inflow Reynolds number due to the dispersion of the core flow throughout the outlet cross-section. It becomes even worse with the presences of secondary flow of 22% to 28%. The secondary flow vortices occur almost the same scale at both left and right sides of the outlet. The flow separation takes place within the inner wall region early on half of the inner wall length and is gradually resolved with the increase of inflow Reynolds number.