The aim of this study is to investigate the effect of boundary conditions on the accuracy and stability of the numerical solution of fluid flows in the context of single relaxation time Lattice Boltzmann method (SRT-LBM). The fluid flows are simulated using regularized, no-slip, Zou-He and bounce back boundary conditions for straight surfaces in a lid driven cavity and the two-dimensional flow ...

By using the trigonometric uniform splines of order 3 with a real tension factor, a numericalmethod is developed for solving a linear second order boundary value problems (2VBP) withDirichlet, Neumann and Cauchy types boundary conditions. The moment at the knots isapproximated by central finite-difference method. The order of convergence of the methodand the theory is illustrated by solving tes...

Consider the Kähler-Ricci flow with finite time singularities over any closed Kähler manifold. We prove the existence of the flow limit in the sense of current towards the time of singularity. This answers affirmatively a problem raised by Tian in [23] on the uniqueness of the weak limit from sequential convergence construction. The notion of minimal singularity introduced by Demailly in the st...

The current study presents the results of the aerodynamic noise prediction of the flow field around a NACA 0012 airfoil at a chord-based Reynolds number of 100,000 and at 8.4 degree angle of attack. An incompressible Large Eddy Simulation (LES) turbulence model is applied to obtain the instantaneous turbulent flow field. The noise prediction is performed by the Ffowcs Williams and Hawkings (FW-...

A direct numerical simulation (DNS) of fully developed turbulent pipe flow is performed at Reτ ≈ 170 and 500 to examine the effect of the streamwise domain length on the convergence of turbulence statistics. Computational domain lengths vary from the πδ to 20πδ. Lower order statistics such as mean flow, turbulence intensities, Reynolds stress, correlations and higher order statistics including ...

In this paper a laminar flow of water on an ice layer subjected to a slip condition is considered numerically. The paper describes a parametric mathematical model to simulate the coupled heat and mass transfer events occurring in moving boundary problems associated with a quasi steady state steady flow process. The discretization technique of the elliptic governing differential equations of mas...

In this paper we prove stability of Robin solid wall boundary conditions for the compressible Navier-Stokes equations. Applications include the no-slip boundary conditions with prescribed temperature or temperature gradient and the first order slip-flow boundary conditions. The formulation is uniform and the transitions between different boundary conditions are done by a change of parameters. W...

Recent developments in computational fluid dynamics are enabling accurate simulations of full scale ship hydrodynamic flow. In particular, Cartesian-grid techniques such as volume-of-fluid and immersed boundary methods expedite computational simulations of unsteady breaking wave flows around complicated ship geometries. However, there are still a number of important numerical and modeling issue...

W e consider a series of simple calculations with a step-function change in thickness of the lithosphere and imposed, far-field boundary conditions to illustrate the influence of the lithosphere on mantle flow. We consider the effect of aspect ratio and far-field boundary conditions on the small-scale flow driven by a discontinuity in the thickness of the lithosphere. In an isothermal mantle, w...

Context. Most of our knowledge on the nonlinear development of the magneto-rotational instability (MRI) relies on the results of numerical simulations employing the shearing box (SB) approximation. A number of difficulties arising from this approach have recently been pointed out in the literature. Aims. We thoroughly examine the effects of the assumptions made and numerical techniques employed...