We study flow scheduling to lightpaths in an optical flow switching network where flow arrivals are modeled as a time dependent Poisson process and their holding times are Pareto distributed. Scheduling decisions are taken at fixed time intervals (larger than 100 ms) in a central node and scheduled flows cannot be interrupted before their completion. The scheduling problem is represented as a d...

Transient natural convection is numerically investigated in an enclosure using variable thermal conductivity, viscosity, and the thermal expansion coefficient of Al2O3-water nanofluid. The study has been conducted for a wide range of Rayleigh numbers (103≤ Ra ≤ 106), concentrations of nanoparticles (0% ≤ ϕ ≤ 7%), the enclosure aspect ratio (AR =1), and temperature differences between the cold a...

Unstable mold flow could induce surface velocity and level fluctuations, and entrain slag, leading to surface defects during continuous casting of steel. Both argon gas injection and ElectroMagnetic Braking (EMBr) greatly affect transient mold flow and stability. Part I of this two-part article investigates transient flow of steel and argon in the nozzle and mold during nominally steady-state c...

OBJECTIVE Flow-pressure curves and vascular impedance are commonly used to investigate pulmonary circulation, but they may be affected at low flow by reflex neurohumoral activation. We therefore investigated the mechanical effects and the reflex effects of decreased flow on pulmonary vascular resistance and impedance. METHODS In ten anaesthetized dogs, we compared flow-pressure curves generat...

This article investigates a generalised solution approach for transient viscoelastic flows employing consistent dynamic boundary conditions. Such a procedure vaunts three key properties independence of reference frame, problem dimension and constitutive equation type. Three different boundary condition protocols have been investigated, two transient and one steady, through a time-dependent incr...

Understanding and modeling of three-phase transient flow in gas-condensate wells play a vital role in designing and optimizing dynamic kill procedure of each well that needs to capture the discontinuities in density, geometry, and velocity of phases but also the effect of temperature on such parameters. In this study, two-phase Advection-Upstream-Splitting-Method (AUSMV) hybrid scheme is extend...

Transient responses of sap flow to step changes in wind speed were experimentally investigated in a wind tunnel. A Granier-type sap flow sensor was calibrated and tested in a cylindrical tube for analysis of its transient time response. Then the sensor was used to measure the transient response of a well-watered Pachira macrocarpa plant to wind speed variations. The transient response of sap fl...

To improve the understanding of the unsteady behavior of supercavitating flows, the author used a three-dimensional Navier-Stokes code (CFDRC, 2000) to model the two-phase flow field around a hemisphere cylinder. The governing equations are discretized on a structured grid using an upwind difference scheme. For different body shapes and cavitation numbers, the cavity shape was determined over t...