We study the dynamics of two-dimensional Poiseuille flow. Firstly we check our calculations with previous results concerning the laminar solution and the minimum Reynolds number such that it becomes unstable. Next we studied time periodic solutions which, because of the imposed periodicity in the stream-wise direction, are rotating waves, what allow us to treat them as stationary flows in a mov...

Numerical solutions of 2-D laminar flow over a backward-facing step at high Reynolds numbers are presented. The governing 2-D steady incompressible Navier–Stokes equations are solved with a very efficient finite difference numerical method which proved to be highly stable even at very high Reynolds numbers. Present solutions of the laminar flow over a backward-facing step are compared with expe...

We determine the initial condition on the laminar-turbulent boundary closest to the laminar state using nonlinear optimization for plane Couette flow. Resorting to the general evolution criterion of nonequilibrium systems we optimize the route to the statistically steady turbulent state, i.e., the state characterized by the largest entropy production. This is the first time information from the...

In the primate visual cortex, the birthdate of neurons in homologous layers differ on either side of the 17-18 border suggesting that there might be different timetables of laminar histogenesis in these two areas (Dehay et al. [1993] Nature 366:464-466 and Kennedy et al. [1996] Soc. Neurosci. Abst. 22:525). Because of the potential importance of these findings for understanding mechanisms that ...

Alternating laminar and turbulent helical bands appearing in shear flows between counterrotating cylinders are accurately computed and the near-wall instability phenomena responsible for their generation identified. The computations show that this intermittent regime can only exist within large domains and that its spiral coherence is not dictated by endwall boundary conditions. A supercritical...

In this paper we introduce k-laminar graphs a new class of graphs which extends the idea of Asteroidal triple free graphs. Indeed a graph is k-laminar if it admits a diametral path that is k-dominating. This bio-inspired class of graphs was motivated by a biological application dealing with sequence similarity networks of reads (called hereafter read networks for short). We briefly develop the ...

OBJECTIVE Evaluate the surgical results of axis screw instrumentation. METHODS Retrospective evaluation of the clinical and radiological data of patients submitted to axis fixation using screws. RESULTS Seventeen patients were surgically treated. The mean age was 41.8 years (range: 12-73). Spinal cord trauma was the most common cause of instability (8 patients - 47%). Bilateral axis fixatio...

1st of november 2005 2 Contents 1 Introduction 1 2 Estimation of temperature gradients in laminar flow through a cylindrical pipe-the assumption of a linear change in wall temperature with axial distance 1 2.1 Temperature distribution in a pipe with circular cross-section assuming a linear wall temperature variation with distance. .. .. 2 3 A ray-tracing analysis of the flow-meter error in the ...

A problem of great concern in aviation and submarine propulsion is the control of the boundary layer and, in particular, the methods to extend the laminar region as a means to decrease noise and fuel consumption. In this paper we study the flow of air along an airfoil when a layer of ionized gas and a longitudinal electric field are created in the boundary layer region. By deriving scaling solu...

Laminar and turbulent pipe flow of a ferrofluid with an imposed linearly polarized, oscillating, magnetic field is examined here. Experimental results show a fractional pressure drop dependence on flow rate, magnetic field strength, and oscillation frequency. Calculations are presented, which show that ferrofluid theory can explain the flow phenomena in laminar and turbulent pipe flow. The mode...