There are different methods for setting the inlet boundary condition (IBC) in large eddy simulation (LES). However, applied same result results. In this study, influence of IBC LES with Lund method, divergence-free synthetic eddies method (DFSEM), and digital filter (DFM) on layer over a flat plate was investigated. For DFM DFSEM, input parameters such as turbulent length scales constant values...

The influence of the exit boundary conditions (vanishing first derivative of the velocity components and constant pressure) on the large eddy simulation of the fully developed turbulent channel flow has been investigated for equidistant and stretched grids at the channel exit. Results show that the chosen exit boundary conditions introduce some small disturbance which is mostly damped by the gr...

This paper provides a method of preliminary design for a two-dimensional, mixed compression, two-ramp supersonic inlet to maximize total pressure recovery and match the mass flow demand of the engine. For an on-design condition, the total pressure recovery is maximized according to the optimization criterion, and the dimensions of the inlet in terms of ratios to the engine face diameter are cal...

Numerical Simulation of three dimensional wave equation is conducted in a cubic domain which contains two parts, part A and part B. Part A of the domain is a I -shaped empty channel, containing air, and part B, containing a solid medium, is the difference between the whole cubic domain and part A. A Dirichlet type boundary condition is specified at the inlet boundary. At all other boundaries of...

The fiber spinning process of a viscoelastic liquid modeled by the constitutive theory of the Maxwell fluid is analyzed. The governing equations are given by one-dimensional mass, momentum and constitutive equations which arise in the slender body approximation by cross-sectional averaging of the two-dimensional axisymmetric Stokes equations with free boundary. Existence, uniqueness and regular...

The implementation and the combination of advanced boundary conditions and subgrid scale models for Large Eddy Simulations are presented. The goal is to perform reliable cold flow LES simulations in complex geometries, such as cylinder engines. In the paper, an inlet boundary condition for synthetic turbulence generation is combined with a fully non reflecting Navier Stokes Characteristic Bound...

Methods We propose a numerical framework for determining pressure field in large arteries, the main components of which are: axi-symmetric 1-D unsteady wave-propagation model with elastic walls and an optimization framework for model personalization via parameter estimation from measured flow and anatomical data (Fig 1). 4D PC MRI data was acquired using a multi-slice phase contrast FLASH cine ...

Today, whereas aeronautical CFD applications are mainly based on Reynolds Average Navier-Stokes modeling, Large Eddy Simulation (L.E.S.) is becoming more used for some of them. LES needs the instantaneous inlet velocity as turbulent inflow boundary conditions which motivates the implementation and validation of a synthetic turbulent inflow condition for LES. The so called "Synthetic Eddy Method...

where the symbols ∆, ∇, and ∇· stand for the Laplacian, gradient, and divergence operators, respectively (∆u is the vector of components ∆ui); the number μ is a viscous constant; f is a given vector function; β = (U,V)t is a given C1 function. The system (1.1) may be obtained by linearizing the steady-state barotropic compressible viscous Navier-Stokes equations without an ambient flow (see [8,...