In many cases, a set of obstacles, such as bridge piers and abutments, are located in the river waterway. Bridge piers disrupt river’s normal flow, and the created turbulence and disturbance causes diversion of flow lines and creates rotational flow. Geometric shape and position of the piers with respect to flow direction and also number of piers and their spacing are effective on changing the ...

Flow visualisation using tracer and particle techniques is well known to be susceptible to fallacious interpretation for unsteady shear flows. Recent experimental observations using these types of techniques have led to the conclusion that even for low Reynolds number flows, the vortex breakdown bubble in a torsionally driven cylinder is not closed and has an inflow/outflow asymmetry at its tai...

A highly accurate Fourier-Chebyshev spectral collocation method has been used to simulate flow in the wake of a sphere in the Reynolds number range from 350 to 650. Flow visualizations and frequency spectra provide a glimpse of the complex vortex dynamics that are observed in the sphere wake. It is found that in addition to the vortex shedding frequency which corresponds to the shedding of larg...

This study aims to develop an alternative vortex analysis method by measuring structure ofIntracranial aneurysm (IA) flow vortexes across the cardiac cycle, to quantify temporal stability of aneurismal flow. Hemodynamics were modeled in "patient-specific" geometries, using computational fluid dynamics (CFD) simulations. Modified versions of known λ2 and Q-criterion methods identified vortex reg...

The flow of a polystyrene Boger fluid through axisymmetric contraction–expansions having various contraction ratios (2 ≤ β ≤ 8) and varying degrees of re-entrant corner curvatures are studied experimentally over a large range of Deborah numbers. The ideal elastic fluid is dilute, monodisperse and well characterized in both shear and transient uniaxial extension. A large enhanced pressure drop a...

a brass vortex tube (vt) with interchangeable parts is used to determine the optimum cold end orifice diameter, main tube length and diameter. experiments were carried out to study the effects of operating pressure as well. it is shown that there is an optimum value for cold end orifice diameter, which is equal to 4mm and there is an optimum value for cold and hot exit temperature difference at...

Much effort has been undertaken for the estimation of propulsive force of swimmers in the front crawl. Estimation is typically based on steady flow theory: the so-called quasi-steady analysis. Flow fields around a swimmer, however, are extremely unsteady because the change direction of hand produces unsteady vortex motions. To evaluate the force correctly, it is necessary to know the unsteady p...