In this study, the general transport equation was subjected to discretization by using the central difference, upwind, hybrid, power-law, exponential scheme and QUICK scheme methods and then solved by using a program prepared in Delphi programming software. In the solution, three different grid systems of 80x100, 160x200 and 320x400 from nodal points were used. The numerical results obtained fo...

2014 The free growth (at constant temperature) of a columnar hexagonal liquid crystal is described. The chosen material is the hexaoctyloxytriphenylene. Three growth regimes are observed depending upon the value of the supersaturation 0394: a petal-shape regime for 0394 0.2, a dendritic regime for 0.2 0394 0.6 and a dense branching regime for 0394 > 0.6. The first morphological transition ...

We use a lattice-Boltzmann based Brownian dynamics simulation to investigate the elongation of DNA at a convergent stagnation point trapped by a uniform attractive potential. The trapping rate of the DNA is not sensitive to the potential and, consistent with a mean field theory, scales as the Peclet number, Pe(1/3) . Surprisingly, we find that the coiled state is favored over the stretched stat...

The spatial Markov model is a Lagrangian random walk model, widely and successfully used for upscaling transport in heterogeneous flows across a broad range of problems. It is particularly useful at early or pre-asymptotic times when many other conventional upscaling approaches may not be valid. However, as with all upscaled models, it must have its limits. In particular, the question of what t...

In this paper we consider the convection-diffusion problem of a passive scalar in Lagrangian coordinates, i.e., in a coordinate system fixed on fluid particles. Both the convection-diffusion partial differential equation and the Langevin equation are expressed in Lagrangian coordinates and are shown to be equivalent for uniform, isotropic diffusion. The Lagrangian diffusivity is proportional to...

Crystallization during the sedimentation process of a binary colloidal hard spheres mixture is explored by Brownian dynamics computer simulations. The two species are different in buoyant mass but have the same interaction diameter. Starting from a completely mixed system in a finite container, gravity is suddenly turned on, and the crystallization process in the sample is monitored. If the Pec...

Linear stability analysis of double diffusive convection in a horizontal porous layer saturated with fluid is examined by considering the effects of viscous dissipation, concentration based internal heat source and vertical throughflow. The basic steady state solution for Governing equations is derived. Linear stability analysis has been implemented numerically by using shooting and Runge-kutta...

Investigation to evaluate axial wall heat conduction has been conducted for heat transfer in a laminar flow circular tube with two classical thermal boundary conditions at the outside wall. The tube ends are either adiabatic or with heat losses. The simulation is three-dimensional with various wall materials, wall thicknesses and tube lengths. A wide range of Peclet number from 7 to 14,000 is c...

In this thesis, mixed primitive variable based finite element formulations are developed to solve linear and nonlinear fluid-structure interaction problems involving incompressible (or almost incompressible) fluid models. The mixed elements are used according to the inf-sup condition. It is pointed out that along the fluid-structure interfaces, different coupling conditions can be used accordin...

Strength of axial mixing in the emulsion phase during progress extraction was evaluated using Peclet number under various flow conditions. The numbers were determined with established tracer technology which applies inert species for iodine extraction. Very little effect operating velocities either aqueous and organic phases found on numbers. This fact indicates that an almost constant degree k...