I Research on fundamentals for multiphase pipelining ................................................... 1 II Accomplishments of our previous DOE/DE-FG02-87ER 13798, 9/1/98--8/31/01...... 2 III Lubricated transport of viscous oils. Friction factor efficiency ratio......................... 5 IV Numerical simulation of laminar wavy core flow...........................................................

in this paper, a new analytical method is proposed to study the effect of crack and axial load on vibration behavior and stability of the cracked columns. using the local flexibility model, the crack has been simulated by a torsional spring with connecting two segments of column in crack location. by solving governing eigenvalue equation, the effect of crack parameters and axial load on the nat...

Plane Couette flow of viscoelastic fluids is shown to exhibit a purely elastic subcritical instability at a very small-Reynolds number in spite of being linearly stable. The mechanism of this instability is proposed and the nonlinear stability analysis of plane Couette flow of the Upper-Convected Maxwell fluid is presented. Above a critical Weissenberg number, a small finite-size perturbation i...

The onset of instability induced by impulsively started rotating cylinder was first investigated experimentally by Chen and Christensen [1]. The initial laminar flow evolves into a secondary flow pattern which consists of a series of Taylor-like vortices. In this transient boundary-layer system the critical time tc to mark the onset of secondary motion becomes an important question. This proble...

Electrokinetic flow instabilities occur under high electric fields in the presence of electrical conductivity gradients. Such instabilities are a key factor limiting the robust performance of complex electrokinetic bio-analytical systems, but can also be exploited for rapid mixing and flow control for microscale devices. This paper reports a representative flow instability phenomenon studied us...

The KelvinHelmholtz (KH) instability is a fundamental wave instability that is frequently observed in all kinds of shear layer (jets, wakes, atmospheric air currents etc). The study of KH-instability, coherent flow structures has a major impact in understanding the fundamentals of fluid dynamics. Therefore there is a need for methods that can identify and analyse these structures. In this Final...

Transport of angular momentum is one of the thrust areas of astrophysical flows. Instabilities and hence the turbulence generated by it has been invoked to understand its role in angular momentum transport in hydrodynamic and magnetohydrodynamic regime. Investigation of an unexplored region described by the parameter space Ω e < 0, Ωe being the epicyclic frequency, resulted in a powerful magnet...

Front tracking has proved to be an accurate and efficient algorithm in the sense that tracking the interface can reduce the error significantly [9,10]. By applying this algorithm, we conduct numerical simulations of Richtmyer–Meshkov (RM) instabilities in spherical geometry for axisymmetric flow. We demonstrate scaling invariance with respect to shock Mach number for fluid mixing statistics, su...