In this paper, we present a fast and accurate method for the combined detection and interactive visualization of vortex structures in 3D flow and their corresponding velocity field. Vortex surfaces are extracted by identifying vortex core lines in combination with isosurfaces of λ2. The velocity field on those vortex surfaces is visualized by a surface LIC method that works in image space. An e...

The sound generated by a vortex moving across a duct section lined with porous materials and the corresponding vortex dynamics are studied numerically in the present investigation. The combined effects of the effective fluid density, the flow resistance, the length, and the thickness of the porous linings on the vortex dynamics and sound generation are examined in detail. Results show that stro...

In our work we examine a high-dimensional, massive flow data set around an airfoil using a topology-based vortex analysis. The 3D time-dependent flow depends on two additional parameters which are introduced by an active flow control technique aiming at increasing the lift by periodic blowing and suction. In particular, we study the influence of the actuation parameters frequency and intensity ...

An anisotropic refinement criterion suitable for Finite-Volume methods is presented and Navier–Stokes solutions are reported for the lid-driven cavity flow configuration at Re 1⁄4 1000 with adaptive anisotropic meshes (h-refinement). The a posteriori error estimation criterion is based on the assessment of the goodness-of-fit of the least squares regression used to perform the variables profile...

This paper describes features in the structure of a laminar vortex ring ejected vertically from an elevated pipe into a uniform horizontal cross flow. Measurements are obtained by particleimage velocimetry (PIV) and flow-visualisation images are obtained by planar-laser-induced fluorescence (PLIF). Cross flow produces a shear layer over the open end of the elevated pipe. As a vortex ring is eje...

flow structure and heat transfer characteristics around two-equal in-tandem square cylinders in the two dimensional laminar and turbulent flow regimes are simulated numerically for reynolds and prandtl numbers, re=1-1×10 5 , pr=0.71, respectively. the investigation is based on an implicit finite volume scheme for integrating the unsteady navier-stokes equations and use of standard κ-ε model to ...

Numerical simulations of PTT fluids in axisymmetric sudden contractions were carried out to investigate the effect of contraction ratio on the flow patterns under conditions of negligible inertia. The PTT model selected has a linear stress coefficient, and contraction ratios (CR) in the range 4:1 to 100:1 were investigated. The simulations are based on a finite volume methodology using very fin...

The generation of vortices for the flow past a flat plate is calculated by the DSMC method. The new intermolecular collision scheme and the conventional one are compared with respect to their allowable cell dimension. In the condition of Re=50, when using the conventional scheme, the vortex behind an inclined flat plate becomes weak with increasing the cell dimension beyond the mean free path, ...

Streamlines, contour lines, vector plots, and volume slices (cutting planes) are commonly used for flow visualization. These techniques are sometimes referred to as instantaneous flow visualization techniques because calculations are based on an instant of the flow field in time. Although instantaneous flow visualization techniques are effective for depicting phenomena in steady flows, they som...

The influence of an external strain (or shear) field on the evolution of two identical vortices is investigated in a twodimensional incompressible fluid. Using point vortex modeling, two regimes of the vortex doublet (co-rotation and irreversible separation) are determined; the critical intensity of the large scale flow separating these two regimes for a given initial separation of vortices, is...