...Xiao-Dong Liu; Mohamed Farhat; Yao-Jun Li; Zhu-Qing Liu; Wei Yang The efficiency of centrifugal pumps drops sharply when the flowrate is reduced below a threshold value. This is due to a profound change in the flow structure, characterized by a large of portion flow separation near the impeller...

... model is used for the mass transfer due to cavitation. Moreover, the skin-friction coefficient and boundary-vorticity flux (BVF) are used to study the flow separation. Numerical results show that the attached shear layer separates from the boundary layer and then squeezes to form the separation line...

.... This study aims to investigate the flow separation characteristics in a PAT impeller under the BEP condition by numerical method. The hydraulic performance and transient pressure characteristics of PAT predicted numerically were verified through experimentation. The surface friction lines and flow...

... between the two disc h/d becomes larger, flow separation occurs more easily, and the influence of the Re becomes stronger. From the numerical result, it was also observed that at different h/d and varying Re , the influence of the entrainment field of the separation bubble is clearly seen...

.... Variation of structure frequency around the junction At the next level of frequency analysis, the difference in structure frequency after flow separation at the junction has been plotted against each other. The figure reveals an inevitable linear relationship. This linearity, therefore, offers yet...

... of excursion in the dynamic location of flow separation, particularly when characteristic flow frequencies couple with the mirror housing natural frequency. References 1 Achenbach , E. , 1974 , “ Vortex Shedding From Spheres ,” J. Fluid Mech. , 62 ( 2 ), pp. 209 – 221 . 10.1017...

... compressible flow flow separation flow simulation Mach number Navier-Stokes equations numerical analysis stagnation flow subsonic flow viscosity The stall of airfoils is a basic phenomenon in aerodynamics which refers to the significant and sudden loss of lift, increase of drag, and change...

... 01 01 2011 14 08 2011 15 09 2011 15 09 2011 boundary layer turbulence external flows flow separation flow visualisation jets pipe flow The jet was produced using a submerged vertical precision type 304 stainless steel tube placed on the cylinder centerline...

.... The visualization of the three-dimensional structures corresponding to the intermediate scales of the flow shows slightly elongated structures preferentially aligned with the jet centerline axis. 01 12 2010 27 07 2011 12 09 2011 12 09 2011 flow separation flow visualisation image...

..., Air-Cooled Heat Exchangers and Cooling Towers: Thermal-Flow Performance Evaluation, Pennwell Corp., Tulsa, OK), can be more than 20% of the total cooling tower flow losses. Flow separation at the lower edge of the shell results in a vena contracta with a distorted inlet velocity distribution...

... 07 06 2011 07 06 2011 boundary layer turbulence flow separation flow visualisation fractals jets shear turbulence wetting An offset jet is formed when a jet discharges into a medium above a wall parallel to the axis of the jet exit but offset by a certain height...

.... The findings of this study suggest that one stall cell rotates with the impeller at sub-synchronous velocity in the vaneless gap between the impeller and the guide vanes. It is the result of rotating flow separations developed in several consecutive impeller channels which lead to their blockage...

... around the cylinder, the current work modified pressure distribution, vortex-shedding characteristics, and aerodynamic forces. In order to reduce the drag and to suppress the periodic forces induced by the surface-flow separation and vortex shedding of the square cylinder, flow-control methods, which...

... pump-turbine turbine brake operation numerical simulation CFD measurement runaway speed no load variable boundary conditions flow separation Reversible pump-turbines utilize excess energy available in electrical grids for pump mode operation and produce peak energy in turbine mode...

... information useful to many practical situations. Many actual flows are characterized by the flow separation of the boundary layer and the subsequent reattachment of the flow downstream, which is a flow structure also seen in the backward-facing step. Backward-facing step geometry In this study...

..., which increase the unsteady loading on the propeller and generate significant noise ( 4 ). When the sail is yawed, a tip vortex is also formed, further complicating the flow in the wake and increasing its detection signature. boundary layer turbulence flow separation flow visualisation...

... 09 2010 29 11 2011 02 03 2011 02 03 2011 boundary layers flow separation flow simulation pipe flow turbulence Computational fluid dynamics (CFD) has been widely utilized in industry in the design of fluid devices. A continuing challenge in CFD, however...

... the JSFR cold-leg piping, are tested experimentally to confirm whether a scale effect in pressure fluctuation characteristics exists. A distinguishing peak can be seen in each power spectrum density (PSD) profile of pressure fluctuation obtained in and downstream of the flow separation region for both...

... configuration. Since the gap guides the volute flow back to the impeller flow field near the shroud high-curvature turning area, the low-momentum jet formed by the gap flow could prevent local flow from separation, reducing the local flow turning losses. However, this jet flow has enlarged flow separation...

...P. A. Gregory; P. N. Joubert; M. S. Chong; A. Ooi The ability of eddy-viscosity models to simulate the turbulent wake produced by cross-flow separation over a curved body of revolution is assessed. The results obtained using the standard k − ω model show excessive levels of turbulent kinetic energy...