[mrj301988]

hi,
plz tell me how can i get info about a cell, after meshing has been done.plz tell me as I am a beginner and using version 1.5 of OpenFoam

[tian]

Hi,

if you need information about your mesh without paraview you can use the "checkMesh".

Bye
Thomas

[mrj301988]

hi

thnkx for ur advice, I have tried that,
i wanted info abt cells on a particular patch.
if u know then plz inform me.

[mrj301988]

hi

if u know then plz tell me, how can i find magnitude of forces acting on a cell, in paraview or without it

[tian]

Hi,

a) in paraview there are some filters to show the mesh quality also. If you need only a particular patch than switch off the other patchs...

http://paraview.org/OnlineHelpCurrent/MeshQuality.html

b) If there is not a special filter for your case about forces (magnitude). You also can try to use the "calculator" in paraview and write down your own equation.

http://paraview.org/OnlineHelpCurrent/Calculator.html

Bye
Thomas

[mrj301988]

hi Tian

thnkx for ur advice
i will definetely try it

[mrj301988]

hi,

when I use calculator following message is shown,
plz do tell me how to rectify it?

ERROR: In /home/dm2/henry/OpenFOAM/ThirdParty/ParaView3.3-cvs/VTK/Common/vtkFunctionParser .cxx, line 1473
vtkFunctionParser (0x1e229a0): Syntax error: expecting a variable name; see position 0

[tian]

Hi,

you make some misstake in equation...

Excample:

you got from your solultion Scalars:

X_Velocity
Y_Velocity
Z_Velocity

Calculator Magnitude: sqrt((X_VELOCITY^2)+(Y_VELOCITY^2)+(Z_VELOCITY^2))

Result Arry Name: Result

Change the Display to: "Result"

Bye
Thomas

[mrj301988]

can u plz tell me the equation in right format, to find force on each cell

[mrj301988]

plz tell me equation for force on each cell in case of a lid driven cavity.

[tian]

Hi,

about forces have a look here:

http://www.cfd-online.com/cgi-bin/Op...how.cgi?1/8402

it seems there are some utilities about forces in OF...

Bye
Thomas

[mrj301988]

hi Tian
thnkx for ur advice,plz tell me for a lid driven cavity,for a particular patch e.g.moving wall how can i find the co-ordinates of face centre and the value of pressure at that point

[tian]

Hi,

if I remember well there was some information about coordinates of face centre in the forum:

"
const vectorField& c = patch().Cf();

Now in variable c you have a vector of each face centre for all faces in your patch.

vectorField will give you a list of vectors for each face centre, each element of which contains the (x y z) coordinates.
"

About the pressure should be working similar...

Bye
Thomas

[mrj301988]

hello, plz tell me

how to calculate the force and moment on a patch or set of patches, e.g. to calculate the lift, drag and moment of an object in the flow.
how to calculate the normalised force and moment on a patch or set of patches, e.g. to calculate the lift, drag and moment coefficients of an object in the flow.

[mrj301988]

hi,

thknx for advice, I could find all parameters,
plz do tell how can i find area of a cell

[henrik]

Hi Mat,

@ "area of a cell": This is not well defined.

Are you after the total area of all faces of a cell, the area of a specific face of a cell or a list of areas for all faces of a patch?

Henrik

[mrj301988]

hi Henrik
I am after list of areas for all faces of a patch.
if u know then plz tell me

[henrik]

Hi Mat,

Sure!

const scalarField& area = patch().magSf();

Henrik

[mrj301988]

hi Henrik,

plz tell me if there is any utility to find area of a patch(all cells in a patch)

[gschaider]

Hi Mat!

You could always abuse the patchIntegrate-utility. Set the boundary condition for some field on that patch to 1 and run the utility on it. The value of the integral should be the patch area.

Bernhard