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A generalized thermal/dynamic wall function: Part 2

Posted October 17, 2016 at 09:24 by sbaffini (NuTBox)
Updated April 28, 2022 at 08:50 by sbaffini

In the first part of this post we left with the problem of computing the following integral:

$f^+\left(y^+,\frac{Pr}{Pr_t}\right)=\int_0^{y+}{\frac{1}{\left[1+\left(\frac{Pr}{Pr_t}\right)\left(\frac{\mu_t}{\mu}\right)\right]}dz^+}$

with:

$\frac{\mu_t}{\mu}\left(y^+,a,k\right)=\frac{\left(ky^+\right)^3}{\left(ky^+\right)^2+\left(ka\right)^3-\left(ka\right)^2}$

I added all the explicit functional dependencies here because we know $f^+\left(y^+,1\right)$ ...

sbaffini

Senior Member

Posted in Basic Fluid Mechanics and CFD

Views 1729 Comments 0 sbaffini is offline

A generalized thermal/dynamic wall function: Part 1

Posted October 14, 2016 at 13:27 by sbaffini (NuTBox)
Updated December 21, 2016 at 10:07 by sbaffini

In a previous post i wrote about an extension of the Reichardt law of the wall to pressure gradient effects. That was derived by assuming the Reichardt profile as a solution for the case without pressure gradient and using integration by parts. In particular, given the the Reichardt function (

is the Von Karman constant):

$f^+\left(y^+\right) = \frac{1}{k}\log\left(1+ky^+\right) +A\left(1-e^{-\frac{y^+}{B}}-\frac{y^+}{B}e^{-\frac{y^+}{C}}\right)$

with:
...

sbaffini

Senior Member

Posted in Basic Fluid Mechanics and CFD

Views 2349 Comments 0 sbaffini is offline

pimpleFoam vs simpleFoam vs pisoFoam vs icoFoam?

Posted October 14, 2016 at 12:27 by kindle
Updated October 24, 2016 at 12:37 by kindle

Quite confusing sometime !

But, why is that a problem needs boundary condition for U and p and all the other possible variables?

pisoFoam has relaxation coef while icoFoam does not have this.

Quote:

UEqn.relax();

Quote:

Originally Posted by ata

Hi
icoFoam is transient solver for incompressible, laminar flow of Newtonian fluids.

pimpleFoam is large time-step transient solver for incompressible, flow using the PIMPLE(merged PISO-SIMPLE) algorithm.

...

kindle

New Member

Posted in Solver

Views 1519 Comments 0 kindle is offline

Viscoelastic Fluid Flows using OpenFOAM The solver viscoelasticFluidFoam

Posted October 14, 2016 at 12:27 by kindle

This guy use Openfoam and FENE-P !!!

Quote:

Originally Posted by mmasoudian

Dear ata
I appreciate your quick answer

I compiled everything and I changed fvSolutions as you mentioned in forum but when I want to run a case (FENE-P): the error is:

mam@ubuntu:~/OpenFOAM/mam-2.0.0/RUN/tutorials/incompressible/viscoelasticFluidFoam/FENE-P$ viscoelasticFluidFoam
/*---------------------------------------------------------------------------*\
| ========= |

...

kindle

New Member

Posted in Viscoelastic

Views 807 Comments 0 kindle is offline

PyFoam

Posted October 12, 2016 at 12:41 by kindle
Updated October 14, 2016 at 11:03 by kindle

4.8 GUI-Tools

4.8.1 pyFoamDisplayBlockMesh.py

Graphically displays a blockMesh and helps highlights selected blocks and patches. It is not a blockMesh-editor, but it helps to find errors in the order of vertices etc (editing of the blockMesh is still done in a text editor).
This needs an installation of the VTK with Python-bindings. The ways to get this are very different on various systems. But usually you have to compile it from the sources. Sorry.
Since...

kindle

New Member

Posted in PyFoam

Views 710 Comments 0 kindle is offline