Shear flow near solids: Epitaxial order and flow boundary conditions

1990 ◽  
Vol 41 (12) ◽  
pp. 6830-6837 ◽  
Author(s):  
Peter A. Thompson ◽  
Mark O. Robbins
Keyword(s):  
Shear Flow ◽  
Boundary Conditions ◽  
Flow Boundary

ON BOUNDARY CONDITIONS IN THE FINITE VOLUME LATTICE BOLTZMANN METHOD ON UNSTRUCTURED MESHES

1999 ◽  
Vol 10 (06) ◽  
pp. 1003-1016 ◽  
Author(s):  
GONGWEN PENG ◽  
HAOWEN XI ◽  
SO-HSIANG CHOU
Keyword(s):  
Shear Flow ◽  
Boundary Conditions ◽  
Numerical Simulations ◽  
Lattice Boltzmann Method ◽  
Finite Volume ◽  
Simple Shear ◽  
Lattice Boltzmann ◽  
Unstructured Meshes ◽  
Simple Shear Flow ◽  
Boltzmann Method

Boundary conditions in a recently-proposed finite volume lattice Boltzmann method are discussed. Numerical simulations for simple shear flow indicate that the extrapolation and the half-covolume techniques for the boundary conditions are workable in conjunction with the finite volume lattice Boltzmann method for arbitrary meshes.

Slip-flow boundary conditions for non-Newtonian lubrication layers

1999 ◽  
Vol 24 (4) ◽  
pp. 211-217 ◽  
Author(s):  
Helge I Andersson ◽  
Ole Andreas Valnes
Keyword(s):  
Boundary Conditions ◽  
Slip Flow ◽  
Flow Boundary

Zero and negative entrainment in turbulent shear flow

1971 ◽  
Vol 46 (2) ◽  
pp. 385-394 ◽  
Author(s):  
M. R. Head ◽  
P. Bradshaw
Keyword(s):  
Boundary Layer ◽  
Shear Flow ◽  
Outer Part ◽  
Radical Change ◽  
The Other ◽  
Turbulent Shear ◽  
Turbulence Structure ◽  
Turbulent Shear Flow ◽  
Flow Boundary ◽  
Other Hand

In certain accelerated flows the entrainment in the boundary layer, as normally defined, may be either zero or negative; on the other hand, there is no reason to suppose, on physical grounds, that the spread of mean or fluctuating vorticity should cease or become negative in such flows. This paradox is resolved in the present paper. It is also shown that in the equilibrium turbulent sink-flow boundary layer, where the entrainment as normally defined is zero, the reduced advection along streamlines in the outer part of the layer comes about mainly through increased dissipation: there is no reason to assume any radical change in the turbulence structure.

scholarly journals COMPUTATIONAL FLUID DYNAMICS STUDY OF PULL AND PLUG FLOW BOUNDARY CONDITION ON NASAL AIRFLOW

2013 ◽  
Vol 25 (04) ◽  
pp. 1350044 ◽  
Author(s):  
Mohammed Zubair ◽  
Vizy Nazira Riazuddin ◽  
Mohammad Zulkifly Abdullah ◽  
Ismail Rushdan ◽  
Ibrahim Lutfi Shuaib ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Boundary Condition ◽  
Computational Fluid Dynamics ◽  
Boundary Conditions ◽  
Comparative Study ◽  
Flow Model ◽  
Plug Flow ◽  
Maximum Velocity ◽  
Nasal Valve ◽  
Flow Boundary

The recent advances in the computer based computational fluid dynamics (CFD) software tools in the study of airflow behavior in the nasal cavity have opened an entirely new field of medical research. This numerical modeling method has provided both engineers and medical specialists with a clearer understanding of the physics associated with the flow in the complicated nasal domain. The outcome of any CFD investigation depends on the appropriateness of the boundary conditions applied. Most researchers have employed plug boundary condition as against the pull flow which closely resembles the physiological phenomenon associated with the breathing mechanism. A comparative study on the effect of using the plug and pull flow boundary conditions are evaluated and their effect on the nasal flow are studied. Discretization error estimation using Richardson's extrapolation (RE) method has also been carried out. The study is based on the numerical model obtained from computed tomographic data of a healthy Malaysian subject. A steady state Reynold averaged Navier–Stokes and continuity equations is solved for inspiratory flow having flow rate 20 L/min representing turbulent boundary conditions. Comparative study is made between the pull and plug flow model. Variation in flow patterns and flow features such as resistance, pressure and velocity are presented. At the nasal valve, the resistance for plug flow is 0.664 Pa-min/L and for pull flow the value is 0.304 Pa-min/L. The maximum velocity at the nasal valve is 3.28 m/s for plug flow and 3.57 m/s for pull flow model.

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