The vector wavelet multi-resolution technique based on the orthogonal wavelet transform was used to analyze the velocity vector data that were simultaneously obtained by sixteen X-wires in the turbulent near-wake of a circular cylinder at different streamwise positions. The instantaneous velocity vector field is decomposed into the multi-scale structures, and its sectional streamline of various...

This study experimentally investigated the instability of flow impingement in a cerebral aneurysm, which was speculated to promote the degradation of aneurysmal wall. A patient-specific, full-scale and elastic-wall replica of cerebral artery was fabricated from transparent silicone rubber. The geometry of the aneurysm corresponded to that found at 9 days before rupture. The flow in a replica wa...

For decades, researchers have worked towards developing a suitable model to represent turbulent boundary layers. Based on PIV experiments in the x − z planes of a turbulent boundary layer, Adrian et al. [1] proposed a model based on a packet of “hairpin vortices” as a primary feature in turbulence transport and production (In this paper, streamwise, spanwise and wall-normal directions are along...

This study explores experimentally the turbulent flow in a laboratory flume, interacting with waves propagated against the flow. It focuses a region of ‘wave-blocking’ for which there is a stream-wise location on the water surface, where the wave propagation velocity vanishes. The observations are corroborated by finding a critical wave frequency for a particular discharge above which the waves...

The aim of present study is to control the unsteady flow structure downstream of a circular cylinder by use of attached permeable plates. Particle image velocimetry (PIV) technique and dye visualization experiments were performed in deep water and the flow characteristics were evaluated by means of time-averaged streamlines, Reynolds Shear Stress and Turbulent Kinetic Energy concentrations. The...

This research presents a numerical simulation of an unsteady two-dimensional channel flow of Newtonian and some non-Newtonian fluids using the finite-volume method. The walls of the geometry oscillate sinusoidally with time. We have used the Cartesian curvilinear coordinates to handle complex geometries, i.e., arterial stents and bulges and the governing Navier–Stokes equations have been modifi...

A spectral element—Fourier method (SEM) for Direct Numerical Simulation (DNS) of the turbulent flow of non-Newtonian fluids is described and the particular requirements for non-Newtonian rheology are discussed. The method is implemented in parallel using the MPI message passing kernel, and execution times scale somewhat less than linearly with the number of CPUs, however this is more than compe...

The oscillatory flow of blood through a stenosed artery is investigated in this paper in presence of magnetic field. The laminar, incompressible, fully developed, Newtonian flow of blood in an artery having mild stenosis is numerically studied under the action of transverse magnetic field and the numerical results are obtained for the oscillatory flow of blood using Shooting method. It is assum...

Recent data on turbulent mixing suggest that the mixing transition, previously documented to occur in shear layers, also occurs in jets, as well as many other flows, and can be regarded as a universal phenomenon. The resulting, fullydeveloped turbulent flow requires a minimum Reynolds number of Re ≈ 104, or a Taylor Reynolds number of ReT ≈ 102, to be sustained. Turbulent mixing in this fully-d...

Submitted for the DFD08 Meeting of The American Physical Society Deformation of Elastic Particles in Viscous Shear Flow TONG GAO, HOWARD HU, University of Pennsylvania — The dynamics of two dimensional elastic particles in a Newtonian viscous shear flow is studied numerically. A constitutive equation is constructed for an incompressible “Neo-Hookean” elastic solid where the extra stress tensor ...