In this paper, three-dimensional (3D) multi-relaxation time (MRT) lattice-Boltzmann (LB) models for multiphase flow are presented. In contrast to the Bhatnagar-GrossKrook (BGK) model, a widely employed kinetic model, in MRT models the rates of relaxation processes owing to collisions of particle populations may be independently adjusted. As a result, the MRT models offer a significant improveme...

Flow field in shallow waters, which is characterized by its complex mixing process and inherent dynamic nature, is interesting mainly due to its practical importance (e. g. in free flushing operation and sedimentation in large reservoirs). 3D numerical models make it possible to track two-dimensional large turbulence coherent structures, which are the dominant phenomenon in shallow reservoirs f...

the complete 3d nonlinear dynamic problem of extensible, flexible risers conveying fluid is considered. for describing the dynamics of the system, the newtonian derivation procedure is followed. the velocity field inside the pipe formulated using hydrostatic and bernoulli equations. the hydrodynamic effects of external fluids are taken into consideration through the nonlinear drag forces in var...

abstract one of the most important sources of drinking and agricultural water needs is rivers. one of the oldest methods of getting water from rivers that still has the greatest use is the gravity intake. in this type of intake, due to the disproportionate velocity at the upstream and downstream mouth of intake, occur flow separation and following sedimentation at the upstream mouth. in this st...

sediment flushing of reservoirs is an operational technique, whereby previously accumulated sediments in the reservoirs are hydraulically removed by accelerated flow when the bottom desiltingoutlets of the dam are opened. in this research, the process of sediment flushing is simulated by a three dimensional numerical model in which sediment and flow interaction are reflected in the reservoirs. ...

In this work, the triple convolution of Daubechies wavelet is used to solve the three dimensional (3D) microscale Dual Phase Lag (DPL) problem. Also, numerical solution of 3D time-dependent initial-boundary value problems of a microscopic heat equation is presented. To generate a 3D wavelet we used the triple convolution of a one dimensional wavelet. Using convolution we get a scaling function ...

Validation of 3D finite element model for free-surface flow is conducted using a high quality and high spatial resolution data set. The present research finds its motivation in the increasing need for efficient management of geophysical flows such as estuaries (multiphase fluid flow) or natural rivers with the complicated channel geometry (e.g. strong channel curvature). A numerical solution is...

The performance of water flooding can be investigated by using either detail numerical modeling or simulation, or simply through the analytical Buckley-Leverett (BL) model. The Buckley-Leverett analytical technique can be applied to one-dimensional homogeneous systems. In this paper, the impact of heterogeneity on water flooding performance and fractional flow curve is investigated. First, a ba...

Numerical simulation of the deformation process during flat rolling of multifilament HTS tapes has been investigated using a commercial FEM program, ELFEN. The numerical models were built up in 2D and 3D using a DruckerPragerKap model for the powder. Three different roll diameters (024 mm, 0 8 5 mm and 0126 mm) have been investigated. It is found that it is possible to perform numerical simulat...