[Tom]

Need help in creating a cgrid around an airfoil with structured mesh using Ansys workbench, CFX Mesh.

Something that looks like that.

http://upload.wikimedia.org/wikibook...ca0015grid.png

Anyone has done it before or can it be done at all. I cant find any tutorials on it.

[PSYMN]

CFX users usually use ICEM CFD Hexa to create meshes like that... The "CFX" version of the product is often called "CAD2Mesh" and includes CFX-Mesh and ICEM CFD Tetra, but you can add on ICEM CFD Hexa...

The CFX-Mesh tool is an unstructured Tetra/Prism mesher.

You may be able to create something similar using ANSYS Meshing, if you can create mapped surface mesh regions and sweep them...

Simon

[SUNSHINE]

Hi Tom,

Mind to give me your email address. I am doing something similiar as you. I got some problems with meshing. I am unable to mesh the aerofoil shape with inflated boundary layer. I have tried many time yet it still fails me.
and i cant upload the photo. Possible i send to you and hope you can help me.

Thank you.

Originally Posted by Tom

Need help in creating a cgrid around an airfoil with structured mesh using Ansys workbench, CFX Mesh.

Something that looks like that.

http://upload.wikimedia.org/wikibook...ca0015grid.png

Anyone has done it before or can it be done at all. I cant find any tutorials on it.

[SUNSHINE]

Hi Guys,

I managed to further improve the Quad Grids around my C-Domain and aerofoil. The domain is 10times the size of foil in scale relation. I've done the following in CFX 2D Extrude Meshing:


http://www.cfd-online.com/Forums/mem...+07-10-09.html

In Inflation settings:
1. Y+ = 1.
2. set ref. Length = 15.34 (equivalent to Prism Height of 9.757e-4)
3. Expansion factor = 1.2
4. set Max Layer to 100.

This is what i've got and this is the best quad quantity i've attained. And its still not perfect to the C-grid posted as a sample in the start of this forum thread.

Hence, the underlying question is what can i do to further increase the quads in my mesh?

If not, should I seriously consider ICEM CFD to generate such mesh?

[PSYMN]

I admit I am biased, but yes, ICEM CFD Hexa could sort this out quickly and give you unparalleled control and quality.

It is also parametric and scriptable making it easy to generate a series of these...

[SUNSHINE]

Hi Simon,

Cheers. Anyplace i can get to download ICEM tutorials please? All the links to tuts in CFD-Online are not relevant.

Regards.

[PSYMN]

You will find tutorials in the help and the example files are included with the install.

Other tutorials and demos can be found on the customer portal.

The training book and tutorials are another set that can be purchased or included with training.

Simon

[PSYMN]

It actually occurs to me that there isn't a tutorial for this simple concept of blocking an airfoil...

I will try to make one (as a movie) and then post it for you (and on www.ansys.com).

Simon

[PSYMN]

In the mean time, there are several 2D hexa tutorials, including the 2D pipe junction and the 2D sedan that will get you headed in the right direction.

Simon

[Sudharshani]

hai...
As a part of my supersonic CD nozzle simulation (after exit the divergent portion of the nozzle)..using
i would like to also see whats happening at the jet plume area of the nozzle exit( to c how the expansion +oblique shocks are being created)....etc
how do i set the boundary condition of the exit of the nozzle as it will also be the (kind of the inlet )of the jet plume section..?
iam using CFX-mesh11.0....so how would i set up
my model contain two sections: (using ANSYS WB i drew two sketches)
(1)sketch1(convergent part+divergent part)
(2)sketch 2(jet plume region)
as the whole section is extruded in Z diection , i cannot select the outlet on my model(as a "opening" B.C) in CFX Mesh for labeling the regions..
....
how should i set the above geometry initially in WB as 2 skeches while it will not appear as a one solid model in CFX-mesh (once the z direction extrudig is done).....?
i hope u understood the question....some help would a very much appreciated.
thank u
sudharshani

[PSYMN]

Do you mean you want a plane for post processing on?

Just put a line (in 2D) and mesh it just as you would any wall... But choose the boundary condition that lets flow just go thru it. THen, when it is time to post process, you can select that component to plot your contours on, etc.

I don't understand why you want to split the model in two... Do you need to solve the two halves separately? Is that what you want? to solve the first part and then use its output profile as the input for the downstream section?

[PSYMN]

Do you mean you want a plane for post processing on?

Just put a line (in 2D) and mesh it just as you would any wall... But choose the boundary condition that lets flow just go thru it. Then, when it is time to post process, you can select that component to plot your contours on, etc.

I don't understand why you want to split the model in two... Do you need to solve the two halves separately? Is that what you want? to solve the first part and then use its output profile as the input for the downstream section?

[rwryne]

Originally Posted by PSYMN

It actually occurs to me that there isn't a tutorial for this simple concept of blocking an airfoil...

I will try to make one (as a movie) and then post it for you (and on www.ansys.com).

Simon

Let us know when you get this, I am sure it'll be of interest to more than just the OP.

I would love it it would also include steps on importing XYZ points in the creation of the airfoil!

[kingjewel1]

Originally Posted by PSYMN

It actually occurs to me that there isn't a tutorial for this simple concept of blocking an airfoil...

I will try to make one (as a movie) and then post it for you (and on www.ansys.com).

Simon

hoi! This is excellent! There are a few movie tutorials on ANYS.com/customer, do you know where I can find more? I'm interested in infection spread within hospitals

Thanks

[PSYMN]

You can find movies on www.ansys.com/demoroom/

We have also recently setup a youtube channel. It doesn't have much up there yet, but more is on the way...

http://www.youtube.com/user/ansysinc

We have also started including movies with each tutorial uploaded in the customer portal...

On the other hand, I still haven't found the time to make that 2D airfoil movie ;^(

[nik]

Hi Simon,

i know that you just said that you haven't found time for the airfoil tutorial, but can you give any directions how to do the meshing around an airfoil using ICEM.

I tried but i am stack and i don't know whats the problem. I created the geometry, meshed the edges but i can't get the c-drid shape. I attached an image of what i have managed to do.

Thanks
Nicolas

[nik]

Eventually after a lot of trial and error I managed to get the mesh. The problem was to match the nodes and the spacing between the connecting edges ( i think ).

[kingjewel1]

Originally Posted by nik

Eventually after a lot of trial and error I managed to get the mesh. The problem was to match the nodes and the spacing between the connecting edges ( i think ).

Cracking job! Would you post a summary/tutorial of the steps you followed? I think that would be really great!

[nik]

Originally Posted by kingjewel1

Cracking job! Would you post a summary/tutorial of the steps you followed? I think that would be really great!

For the geometry and the mesh spacing i used the directions from the following link. http://courses.cit.cornell.edu/fluent/airfoil/step1.htm
It is for GAMBIT but it helped a lot.

I used the "Curve Mesh Setup" to define the number of nodes and the spacing for the curves. For the spacing i used the Advanced Bunching parameters. For the airfoil edges i had to define the 'num. of layers' and the ratio they where increasing in order to match the node spacing of the connecting edges. I had to fiddle with that to get it right.

I don't know if this is the right way to do it, but it worked for me. I hope i helped!

Nicolas

[revanth]

Hi guys,

We have workbench 12 installed on our systems and I was using the analysis flow (fluent) ...I figured out how to draw a geometry and mesh it using cfx mesh method.The manual guides me how to apply boundary conditions by creating a composite 2D region and assigning a name to it..and after generating the volume mesh and when I exported it into fluent...the zone names are not specified in the boundary conditions and I was stuck here ...Can anyone help me and I would be more than happy if any one can provide some example tutorials....

I had another question regarding the ICEM CFD...Wii this s/w help me in meshing and setting the boundary conditions and export that into FLUENT as GAMBIT did ..

Thanks in advance