BACKGROUND CT perfusion (CTP) is an important diagnostic tool for the imaging of cerebral hemodynamics. To obtain quantitative values of cerebral blood volume (CBV), blood flow (CBF), and mean transit time (MTT), measurement of the arterial input function (AIF) is required. To correct for partial volume effects (PVEs), it is common to normalize the AIF with respect to the venous output function...

Additional to a behavior switching between solid-like and liquid-like, dense granular flows also present propagating grain size-dependent effects called non-local effects. Such behaviors cannot be efficiently modeled by standard rheologies such as µ( I )-rheology but have dealt with advanced models. Unfortunately, these models are still new used easily nor for various configurations. We propose...

in this paper, direct numerical simulation of two-phase incompressible gas-liquid flow for simulation of bubble motion in a microtube is presented. microtube radius is 10 µm. the interface is tracked using volume of fluid (vof) method with continuous surface force (csf) model. the flow is solved using a finite volume scheme, based on piso algorithm. numerical simulation is performed on a axisym...

The Moment-of-Fluid (MOF) method is a new volume-tracking method that accurately treats evolving material interfaces. The MOF method uses moment data, namely the material volume fraction, as well as the centroid, for a more accurate representation of the material configuration, interfaces and concomitant volume advection. In contrast, the Volume-of-Fluid (VOF) method uses only volume fraction d...

Volume of fluid (VOF) method is a sharp interface employed for simulations two phase flows. Interface in VOF usually represented using piecewise linear line segments each computational grid based on the volume fraction field. While cartesian coordinates conserve mass exactly, existing algorithms do not show machine-precision conservation axisymmetric coordinate systems. In this work, we propose...

Forced convective condensation in vertical channel is investigated numerically. The condensation boundary layers that occur due to temperature difference between the walls and saturation temperature of steam is simulated by the volume of fluid (VOF) method. The effect of variations in the hydraulic diameter, steam velocity, Re number and temperature difference between the wall and saturation te...

Subcooled flow boiling in multi-microchannels can be used as an efficient thermal management approach in compact electrical devices. Highly subcooled flow boiling of HFE 7100 is studied in two microchannel heat sinks to choose a proper numerical model for simulating boiling flows in microchannels. Results of five different numerical models, including Volume of Fluid (VOF), Eulerian boiling, Eul...

free surface sloshing of liquid in a rectangular tank induced by lateral excitation has been studied numericallyand experimentally in this paper. the numerical simulation is carried out based on the volume of fluid (vof) method that provides free surface extraction in such problem. a tank with transparent walls is used to free surface tracking in experimental study while the movement amplitude ...

A mathematical model to describe the globular transfer in gas metal arc welding is developed. This work is both theoretical and experimental. Using the volume-of-fluid (VOF) method, the fluid-flow and heat-transfer phenomena during the impingement of a droplet on a solid substrate, arc striking, the impingement of multiple droplets on the molten pool and finally the solidification after the arc...