Pre-sedimentation basins are among the most important elements of the conventional water treatment process. In pre-sedimentation basins, due to different velocity gradients, secondary and rotational flows are formed that will create short paths and increase dead and still flow zones as well as changes in the flow mixing. This will prevent laminar flow conditions for sedimentation and will reduc...

In this paper, the Al2O3-water nanofluid flow in laminar and turbulent flows inside tubes fitted with diamond-shaped turbulators is numerically modeled. The nanofluid flow is modeled by employing a two-phase mixture method and applying the constant heat flux boundary condition at tube walls. In the results, the effects of different parameters such as the geometry of turbulators, volume fraction...

This paper describes the conditions for initiation and maintenance of secondary currents in open channel flows. By analyzing the Reynolds equation in the wall-normal and wall-tangent directions, this study reveals that, like other types of vortices, the secondary currents are originated in the near-boundary region, and the magnitude (or strength) of secondary flow is proportional to the lateral...

this paper presents a numerical simulation of developing flow and heat transfer of a viscoelastic fluid in a rectangular duct. in fully developed flow of a viscoelastic fluid in a non-circular duct, secondary flows normal to the flow direction are expected to enhance the rate of heat and mass transfer. on the other hand, properties such as viscosity, thermal conductivity, specific heat and rela...

The results from a steady, viscous flow simulation of the main flowpath of a modern jet engine transonic highpressure turbine, transition duct, and first vane of the low-pressure turbine, coupled with the secondary-air system under the high-pressure turbine, is presented. The secondary-air system configuration includes the lower cavity near the centerline, the mid-cavity with the tangential onb...