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A rotating mass of fluid is known as vortex and the motion of the rotating mass of fluid is known as vortex motion. Vorticity is the circulation per unit area. In this research simulation of a vortex chamber is to be carried out in ANSYS CFD taking water as fluid domain for generating a water vortex that is capable enough to move a turbine for electricity generation. The CAD modelling of the setup was set down and simulation was done in fine mesh by taking suitable wall function in the model of a cylindrical chamber along with a rectangular channel with a contraction portion at the end of it where good amount of vortex generation was acquired by observing velocity and pressure by setting different parameters. The results shows the pressure and velocity contours with 3D velocity streamline flow and the curve of the velocity and pressure curve shows the decrease of pressure and increase of velocity from inlet to outlet that leads to a decent vortex generation. [ABSTRACT FROM AUTHOR]

Much work has been conducted on the topic of forward osmosis (FO), but only a few studies have focused on mitigating external concentration polarization (ECP). This study introduced a simple structure, the corrugated wall channel, to the design of FO module, to induce vortex, and then mitigate ECP. In this study, the corrugated wall channel module (CWCM) was tested under given conditions, with a traditional flat membrane module (FMM) as control. CWCM could mitigate ECP and then enhance water flux. When deionized water was taken as feed solution (FS) and 2-M NaCl solution as draw solution (DS), the water flux enhancement was 16.49 and 18.51% in FO mode (active layer facing FS) and PRO mode (active layer facing DS), respectively. When 0.5-M NaCl solution was taken as FS, the corresponding values were 15.92 and 17.13%, respectively. Computational fluid dynamics (CFD) analysis showed that the CWCM could induce vortex, promote the mixing of the solution in the module, and further contribute to the increase of water flux. The specific shape of CWCM affected its performance on mitigating ECP. Also, the more tortuous CWCM exhibited higher water flux. In addition, CWCM could lessen membrane fouling. [ABSTRACT FROM AUTHOR]

The concepts and methods of the visual representation of fluid dynamics computations of vortical flows are studied. Approaches to the visualization of vortical flows based on the use of various definitions of a vortex and various tests for its identification are discussed. Examples of the visual representation of solutions to some fluid dynamics problems related to the computation of vortical flows in jets, channels, and cavities and of the computation of separated flows occurring in flows around bodies of various shapes are discussed. [ABSTRACT FROM AUTHOR]

The design of turbine blades is a critical issue in the performance of vertical-axis wind-turbines (VAWTs). In a previous study, it is discovered that a loss of thrust in VAWT blades with a wave-like leading edge can be attributed primarily to vortex distribution. This finding prompted us to apply the wave-like blade design to the trailing edge rather than the leading edge. In this study, computational fluid dynamics was used to observe the flow field on straight and tubercle blades in order to predict the resulting thrust and power performance. Increasing the amplitude and wavelength of the tubercle was shown to increase the maximum thrust by as much as 2.31% and the power coefficient by 16.4%, compared to a straight blade. Furthermore, the overall and maximum thrust performance of blades with a modified trailing edge was shown to exceed those of blades with a wave-like leading edge, due to a shift in the location of the vortices by the induced flow. [ABSTRACT FROM AUTHOR]

Wall deposition is one of the most conventional problems in the spray drying process. The operation of a spray dryer is affected by the wall deposition fluxes inside the equipment. In this study, computational fluid dynamic (CFD) simulation was used to investigate the effect of spray dryer geometry on wall deposition. A CFD model was developed for different geometries of spray dryer with a conical (case A) or a parabolic (cases B and C) bottom. The results implied that the parabolic geometry resulted in a lower deposition rate on the spray dryer walls. A comparison of results using the P-values (F-test) of the air velocity, in the conical and parabolic geometries, showed that there was a significant difference in air stability between them. The flow field in conical geometry case A was significantly more unstable, and parabolic geometry case C produced the most uniform airflow patterns. Moreover, the higher wall shear stress in case C, with lower values of the vorticity, would result in less wall deposition. [ABSTRACT FROM PUBLISHER]

For the new sandglass-type floating body with special shape, this paper mainly analyzes the characteristic of the heave damping and its corresponding components by computational fluid dynamics (CFD) method. Firstly, the convergence and accuracy of the CFD method to simulate the heave motion of sandglass-type floating body were validated along with the experimental data. Secondly, the numerical model of the floating body with forced heave motion was created, and then hydrodynamic forces versus different motion amplitudes were calculated and compared to discuss its nonlinear characteristics. Afterwards, based on time-history curves of the hydrodynamic force, heaving added mass and damping of the floating body versus various frequencies were achieved and found to be different from the potential results. In order to analyze the reasons that cause difference, numerical simulations using inviscid and k-ε turbulent models were performed respectively, and the results indicate that the effect of fluid viscosity on the hydrodynamic coefficients is small and not decisive. Then equivalent radiation damping based on CFD wave elevation was deduced to explore the relation between the inviscid CFD and potential models. Finally, local wave field and vorticity field near the body were mainly discussed, and quantitative analysis based on mechanical energy was performed to verify that the vortex due to the body shape is the essential cause of the heave damping for the sandglass-type floating body. • Numerical method to simulate the heave motion of the new sandglass-type FPSO were validated. • Equivalent radiation damping based on CFD solutions was deduced and discussed with the potential results. • Vortex generated by the non-viscous fluid separation was analyzed based on mechanical energy. [ABSTRACT FROM AUTHOR]