Direct numerical simulation of turbulent flow behind a cylinder, wake flow, using the random vortex method for an incompressible fluid in two dimensions is presented. In the random vortex method, the primary variable is vorticity of the flow field. After generation on the cylinder wall, it is followed in two fractional time step in a Lagrangian system of coordinates, namely convection and diffu...

Vortex rings are one of the fundamental flow structures in nature. In this paper, the generation of circulation and vortex rings by a vortex generator with a static converging conic nozzle exit is studied numerically. Conic nozzles can manipulate circulation and other flow invariants by accelerating the flow, increasing the Reynolds number, and by establishing a two-dimensional flow at the exit...

BACKGROUND LV diastolic vortex formation has been suggested to critically contribute to efficient blood pumping function, while altered vortex formation has been associated with LV pathologies. Therefore, quantitative characterization of vortex flow might provide a novel objective tool for evaluating LV function. The objectives of this study were 1) assess feasibility of vortex flow analysis du...

Introduction: Characterization of turbulence phenomena in fluid transport systems is useful in understanding energy conservation, dissipation, and exchange. Vortices, structures exhibiting circular or swirling motion, are central in defining flow fields and flow structure. Formation of vortices and changes in their structure are determined by structural geometry of the system as well as other g...

this paper presents the results of numerical simulations of the laminar and turbulent flows inside diverging channels using random vortex methods (rvm). random vortex method is a mesh-free method which solves unsteady vorticity equation instead of solving navier-stokes equations directly to determine the velocity field. in this paper, the velocity potential, which is used as the initial conditi...

Dual turbocharger turbine is fed by an unequal out-of-phase mass flow charge almost all the time which have significant effects on its performance parameters and flow phenomena which are not well known. Besides fully understanding the flow behavior in the radial turbine suffers from lack of detailed information about the secondary flows. This article studies the secondary flow structure within ...

water conveyance through pumping takes a lot of energy and cost and therefore, its application should be accompanied by exact design of pumping station as well as correct positions of pumps and their subsidiary apparatus. sumps are designed for many pumping stations and often face the problems of vortex and irregular flows. therefore an investigation of the general flow pattern in sumps in diff...

Vortices can develop in intakes of turbojet and turbo fan aero engines during high power operation in the vicinity of solid surfaces. These vortices can cause catastrophic damage to the engine. The factors determining the formation of the vortex include both geometric dimensions as well as flow parameters. It was shown that the threshold at which the vortex forms or disappears is also dependent...

The sound generated by a vortex propagating across a two-dimensional duct section with flexible walls (membranes) in an infinitely long rigid duct conveying a flow is investigated numerically using the matched asymptotic expansion technique and the potential theory. The effects of the initial vortex position, the mechanical properties of the flexible walls, and the mean flow on the sound genera...