[GiDlist] airfoil mesh

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Benjamin Sanderse

[GiDlist] airfoil mesh

Post by Benjamin Sanderse »

Hello all,

I just started some time ago meshing with GiD. I just have a simple airfoil
(2D) in a circular domain.
I want GiD to create a C or O-grid for my geometry. I tried several
possibilities, but I could not find a way to generate a good airfoil mesh.
My mesh is always very refined at the leading and trailing edge, but misses
refinement near the surface and in the wake.
As wing and airfoil meshing must be a common practice I am wondering if
anybody could help me with this.
For convenience I attached my geometry as .gid file.

Thank you so much,

Benjamin
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Jose Munoz

[GiDlist] Quadratic and linear elements

Post by Jose Munoz »

Hello all,

Is it possible to combine linear and quadratic elements in the same model?

Many thanks,

Jose
User avatar
abelcs
Posts: 146
Joined: Mon Oct 13, 2014 9:14 am

[GiDlist] Quadratic and linear elements

Post by abelcs »

Hello Jose,

By the moment this is not possible using GiD. The whole model must be linear
or quadratic.

Regards,

ABEL

__________________________________________________________

Abel Coll Sans

CIMNE - International Center for Numerical Methods in Engineering

Office C2 - C1Building - Campus Nord UPC

Gran Capità s/n, 08034 Barcelona

Tfn: 34 - 93 401 74 03 Fax: 34 - 93 401 65 17

abelcs at cimne.upc.edu

_________________________________________________________

-----Mensaje original-----
De: gidlist-admin at gatxan.cimne.upc.edu
[mailto:gidlist-admin at gatxan.cimne.upc.edu] En nombre de Jose Munoz
Enviado el: miércoles, 22 de noviembre de 2006 9:19
Para: gidlist at gatxan.cimne.upc.edu
Asunto: [GiDlist] Quadratic and linear elements

Hello all,

Is it possible to combine linear and quadratic elements in the same model?

Many thanks,

Jose
_______________________________________________
GiDlist mailing list
GiDlist at gid.cimne.upc.es
http://gid.cimne.upc.es/mailman/listinfo/gidlist
User avatar
miguel
Posts: 361
Joined: Thu Sep 25, 2014 9:04 am

[GiDlist] Quadratic and linear elements

Post by miguel »

Hello,
In postproces yes, it is posible to mix linear and quadratic elements, but
in preprocess, in the mesh generation the elements are restricted to have
the same order: all elements should be linear or quadratic.
Hope it helps,

Miguel

-----Mensaje original-----
De: gidlist-admin at gatxan.cimne.upc.edu
[mailto:gidlist-admin at gatxan.cimne.upc.edu] En nombre de Jose Munoz
Enviado el: miércoles, 22 de noviembre de 2006 9:19
Para: gidlist at gatxan.cimne.upc.edu
Asunto: [GiDlist] Quadratic and linear elements

Hello all,

Is it possible to combine linear and quadratic elements in the same model?

Many thanks,

Jose
_______________________________________________
GiDlist mailing list
GiDlist at gid.cimne.upc.es
http://gid.cimne.upc.es/mailman/listinfo/gidlist
User avatar
abelcs
Posts: 146
Joined: Mon Oct 13, 2014 9:14 am

[GiDlist] airfoil mesh

Post by abelcs »

Hello Benjamin,



To refine the mesh near any geometrical entity you must assign a prescribed
size of the mesh to the entity (Mesh-Unstructured-Assign sizes on
).



I recommend you to do the meshing tutorials available in the web site
(http://www.gidhome.com/support/su05.subst) to be able to take advantage of
all the GiD meshing possibilities.



Regards,



ABEL

__________________________________________________________

Abel Coll Sans

CIMNE - International Center for Numerical Methods in Engineering

Office C2 - C1Building - Campus Nord UPC

Gran Capità s/n, 08034 Barcelona

Tfn: 34 - 93 401 74 03 Fax: 34 - 93 401 65 17

mailto:abelcs at cimne.upc.edu abelcs at cimne.upc.edu

_________________________________________________________

_____

De: gidlist-admin at gatxan.cimne.upc.edu
[mailto:gidlist-admin at gatxan.cimne.upc.edu] En nombre de Benjamin Sanderse
Enviado el: martes, 21 de noviembre de 2006 23:24
Para: gidlist at gatxan.cimne.upc.es
Asunto: [GiDlist] airfoil mesh



Hello all,



I just started some time ago meshing with GiD. I just have a simple airfoil
(2D) in a circular domain.

I want GiD to create a C or O-grid for my geometry. I tried several
possibilities, but I could not find a way to generate a good airfoil mesh.

My mesh is always very refined at the leading and trailing edge, but misses
refinement near the surface and in the wake.

As wing and airfoil meshing must be a common practice I am wondering if
anybody could help me with this.

For convenience I attached my geometry as .gid file.



Thank you so much,



Benjamin

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Benjamin Sanderse

[GiDlist] airfoil mesh

Post by Benjamin Sanderse »

Hello,

I did the tutorials and I prescribed the size of the mesh at the boundary of
the airfoil. However, that does not give me the expected result: the mesh
near the leading and trailing edge is still much finer, and the elements
close to the surface look quite bad (in terms of aspect ratio and corner
angles).
I tried now to use structured elements instead, but somehow that only works
if your surface is the topological equivalent of a rectangle...so that means
that I will never be able to create a structured mesh in 2D inbetween an
airfoil surface and a boundary?? Sounds strange to me.


Benjamin


On 11/22/06, Abel Coll abelcs at cimne.upc.edu wrote:



Hello Benjamin,



To refine the mesh near any geometrical entity you must assign a
prescribed size of the mesh to the entity (Mesh-Unstructured-Assign sizes
on…).



I recommend you to do the meshing tutorials available in the web site (
http://www.gidhome.com/support/su05.subst) to be able to take advantage of
all the GiD meshing possibilities.



Regards,



ABEL

__________________________________________________________

*Abel Coll Sans*

*CIMNE - *International Center for Numerical Methods in Engineering

Office C2 - C1Building - Campus Nord UPC

Gran Capità s/n, 08034 Barcelona

Tfn: 34 - 93 401 74 03 Fax: 34 - 93 401 65 17

abelcs at cimne.upc.edu

_________________________________________________________
------------------------------

*De:* gidlist-admin at gatxan.cimne.upc.edu [mailto:
gidlist-admin at gatxan.cimne.upc.edu] *En nombre de *Benjamin Sanderse
*Enviado el:* martes, 21 de noviembre de 2006 23:24
*Para:* gidlist at gatxan.cimne.upc.es
*Asunto:* [GiDlist] airfoil mesh



Hello all,



I just started some time ago meshing with GiD. I just have a simple
airfoil (2D) in a circular domain.

I want GiD to create a C or O-grid for my geometry. I tried several
possibilities, but I could not find a way to generate a good airfoil mesh.

My mesh is always very refined at the leading and trailing edge, but
misses refinement near the surface and in the wake.

As wing and airfoil meshing must be a common practice I am wondering if
anybody could help me with this.

For convenience I attached my geometry as .gid file.



Thank you so much,



Benjamin

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User avatar
abelcs
Posts: 146
Joined: Mon Oct 13, 2014 9:14 am

[GiDlist] airfoil mesh

Post by abelcs »

Hi,



In relation with the quality of the elements, if your meshes are obtained
using Rfast mesher, you can set Rsurf mesher (in
Preferences-meshing-Surface mesher) and probably the elements would be
better.



ABEL

__________________________________________________________

Abel Coll Sans

CIMNE - International Center for Numerical Methods in Engineering

Office C2 - C1Building - Campus Nord UPC

Gran Capità s/n, 08034 Barcelona

Tfn: 34 - 93 401 74 03 Fax: 34 - 93 401 65 17

mailto:abelcs at cimne.upc.edu abelcs at cimne.upc.edu

_________________________________________________________

_____

De: gidlist-admin at gatxan.cimne.upc.edu
[mailto:gidlist-admin at gatxan.cimne.upc.edu] En nombre de Benjamin Sanderse
Enviado el: miércoles, 22 de noviembre de 2006 15:54
Para: gidlist at gatxan.cimne.upc.edu
Asunto: Re: [GiDlist] airfoil mesh



Hello,



I did the tutorials and I prescribed the size of the mesh at the boundary of
the airfoil. However, that does not give me the expected result: the mesh
near the leading and trailing edge is still much finer, and the elements
close to the surface look quite bad (in terms of aspect ratio and corner
angles).

I tried now to use structured elements instead, but somehow that only works
if your surface is the topological equivalent of a rectangle...so that means
that I will never be able to create a structured mesh in 2D inbetween an
airfoil surface and a boundary?? Sounds strange to me.




Benjamin




On 11/22/06, Abel Coll abelcs at cimne.upc.edu wrote:



Hello Benjamin,



To refine the mesh near any geometrical entity you must assign a prescribed
size of the mesh to the entity (Mesh-Unstructured-Assign sizes on
).



I recommend you to do the meshing tutorials available in the web site (
http://www.gidhome.com/support/su05.subst
http://www.gidhome.com/support/su05.subst ) to be able to take advantage
of all the GiD meshing possibilities.



Regards,



ABEL

__________________________________________________________

Abel Coll Sans

CIMNE - International Center for Numerical Methods in Engineering

Office C2 - C1Building - Campus Nord UPC

Gran Capità s/n, 08034 Barcelona

Tfn: 34 - 93 401 74 03 Fax: 34 - 93 401 65 17

mailto:abelcs at cimne.upc.edu abelcs at cimne.upc.edu

_________________________________________________________

_____

De: gidlist-admin at gatxan.cimne.upc.edu
[mailto:gidlist-admin at gatxan.cimne.upc.edu] En nombre de Benjamin Sanderse
Enviado el: martes, 21 de noviembre de 2006 23:24
Para: gidlist at gatxan.cimne.upc.es
Asunto: [GiDlist] airfoil mesh



Hello all,



I just started some time ago meshing with GiD. I just have a simple airfoil
(2D) in a circular domain.

I want GiD to create a C or O-grid for my geometry. I tried several
possibilities, but I could not find a way to generate a good airfoil mesh.

My mesh is always very refined at the leading and trailing edge, but misses
refinement near the surface and in the wake.

As wing and airfoil meshing must be a common practice I am wondering if
anybody could help me with this.

For convenience I attached my geometry as .gid file.



Thank you so much,



Benjamin



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Benjamin Sanderse

[GiDlist] airfoil mesh

Post by Benjamin Sanderse »

Hello,

Is it possible to make a transition from an structured quadrilateral mesh (boundary layer) to an unstructured quadrilateral mesh (far field)?
I tried this, but I get the following error:

Quadrilaterals cannot be meshed. All contour lines must have an even number of sides

I even tried it with a simple example of two rectangles that have one side in common, and it doesn't work to put structured quads in the first and unstructured in the second. Please help...

Thank you,

Benjamin

----- Original Message -----
From: Abel Coll
To: gidlist at gatxan.cimne.upc.edu
Sent: Thursday, November 23, 2006 4:43 AM
Subject: RE: [GiDlist] airfoil mesh


Hi,



In relation with the quality of the elements, if your meshes are obtained using Rfast mesher, you can set Rsurf mesher (in Preferences-meshing-Surface mesher) and probably the elements would be better.



ABEL

__________________________________________________________

Abel Coll Sans

CIMNE - International Center for Numerical Methods in Engineering

Office C2 - C1Building - Campus Nord UPC

Gran Capità s/n, 08034 Barcelona

Tfn: 34 - 93 401 74 03 Fax: 34 - 93 401 65 17

abelcs at cimne.upc.edu

_________________________________________________________


------------------------------------------------------------------------------

De: gidlist-admin at gatxan.cimne.upc.edu [mailto:gidlist-admin at gatxan.cimne.upc.edu] En nombre de Benjamin Sanderse
Enviado el: miércoles, 22 de noviembre de 2006 15:54
Para: gidlist at gatxan.cimne.upc.edu
Asunto: Re: [GiDlist] airfoil mesh



Hello,



I did the tutorials and I prescribed the size of the mesh at the boundary of the airfoil. However, that does not give me the expected result: the mesh near the leading and trailing edge is still much finer, and the elements close to the surface look quite bad (in terms of aspect ratio and corner angles).

I tried now to use structured elements instead, but somehow that only works if your surface is the topological equivalent of a rectangle...so that means that I will never be able to create a structured mesh in 2D inbetween an airfoil surface and a boundary?? Sounds strange to me.




Benjamin




On 11/22/06, Abel Coll abelcs at cimne.upc.edu wrote:



Hello Benjamin,



To refine the mesh near any geometrical entity you must assign a prescribed size of the mesh to the entity (Mesh-Unstructured-Assign sizes on.).



I recommend you to do the meshing tutorials available in the web site ( http://www.gidhome.com/support/su05.subst) to be able to take advantage of all the GiD meshing possibilities.



Regards,



ABEL

__________________________________________________________

Abel Coll Sans

CIMNE - International Center for Numerical Methods in Engineering

Office C2 - C1Building - Campus Nord UPC

Gran Capità s/n, 08034 Barcelona

Tfn: 34 - 93 401 74 03 Fax: 34 - 93 401 65 17

abelcs at cimne.upc.edu

_________________________________________________________


------------------------------------------------------------------------------

De: gidlist-admin at gatxan.cimne.upc.edu [mailto:gidlist-admin at gatxan.cimne.upc.edu] En nombre de Benjamin Sanderse
Enviado el: martes, 21 de noviembre de 2006 23:24
Para: gidlist at gatxan.cimne.upc.es
Asunto: [GiDlist] airfoil mesh



Hello all,



I just started some time ago meshing with GiD. I just have a simple airfoil (2D) in a circular domain.

I want GiD to create a C or O-grid for my geometry. I tried several possibilities, but I could not find a way to generate a good airfoil mesh.

My mesh is always very refined at the leading and trailing edge, but misses refinement near the surface and in the wake.

As wing and airfoil meshing must be a common practice I am wondering if anybody could help me with this.

For convenience I attached my geometry as .gid file.



Thank you so much,



Benjamin


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User avatar
escolano
Posts: 1918
Joined: Sun Sep 05, 1982 10:51 pm

[GiDlist] airfoil mesh

Post by escolano »

As said the error message:

"Quadrilaterals cannot be meshed. All contour lines must have an even number of sides"

You musn't assing an uneven number of divisions to the structured sides (when are connected to the unstructured quadrilaterals).

This is because a subdivision algorithm is used for unstructured quadrilaterals, then the number of subdivisions of its boundary lines
must be multiple of 2.

If you don't assign manually the number of divisions, GiD automatically generate an even number of sides for neighbor entities.

In any case, unstructured quadrilaterals generated by GiD, in general, doesn't have high shape quality.
It's more recommended to use unstructured triangles.

Enrique
----- Original Message -----
From: Benjamin Sanderse
To: gidlist at gatxan.cimne.upc.edu
Sent: Friday, November 24, 2006 8:11 PM
Subject: Re: [GiDlist] airfoil mesh


Hello,

Is it possible to make a transition from an structured quadrilateral mesh (boundary layer) to an unstructured quadrilateral mesh (far field)?
I tried this, but I get the following error:

Quadrilaterals cannot be meshed. All contour lines must have an even number of sides

I even tried it with a simple example of two rectangles that have one side in common, and it doesn't work to put structured quads in the first and unstructured in the second. Please help...

Thank you,

Benjamin

----- Original Message -----
From: Abel Coll
To: gidlist at gatxan.cimne.upc.edu
Sent: Thursday, November 23, 2006 4:43 AM
Subject: RE: [GiDlist] airfoil mesh


Hi,



In relation with the quality of the elements, if your meshes are obtained using Rfast mesher, you can set Rsurf mesher (in Preferences-meshing-Surface mesher) and probably the elements would be better.



ABEL

__________________________________________________________

Abel Coll Sans

CIMNE - International Center for Numerical Methods in Engineering

Office C2 - C1Building - Campus Nord UPC

Gran Capità s/n, 08034 Barcelona

Tfn: 34 - 93 401 74 03 Fax: 34 - 93 401 65 17

abelcs at cimne.upc.edu

_________________________________________________________


----------------------------------------------------------------------------

De: gidlist-admin at gatxan.cimne.upc.edu [mailto:gidlist-admin at gatxan.cimne.upc.edu] En nombre de Benjamin Sanderse
Enviado el: miércoles, 22 de noviembre de 2006 15:54
Para: gidlist at gatxan.cimne.upc.edu
Asunto: Re: [GiDlist] airfoil mesh



Hello,



I did the tutorials and I prescribed the size of the mesh at the boundary of the airfoil. However, that does not give me the expected result: the mesh near the leading and trailing edge is still much finer, and the elements close to the surface look quite bad (in terms of aspect ratio and corner angles).

I tried now to use structured elements instead, but somehow that only works if your surface is the topological equivalent of a rectangle...so that means that I will never be able to create a structured mesh in 2D inbetween an airfoil surface and a boundary?? Sounds strange to me.




Benjamin




On 11/22/06, Abel Coll abelcs at cimne.upc.edu wrote:



Hello Benjamin,



To refine the mesh near any geometrical entity you must assign a prescribed size of the mesh to the entity (Mesh-Unstructured-Assign sizes on.).



I recommend you to do the meshing tutorials available in the web site ( http://www.gidhome.com/support/su05.subst) to be able to take advantage of all the GiD meshing possibilities.



Regards,



ABEL

__________________________________________________________

Abel Coll Sans

CIMNE - International Center for Numerical Methods in Engineering

Office C2 - C1Building - Campus Nord UPC

Gran Capità s/n, 08034 Barcelona

Tfn: 34 - 93 401 74 03 Fax: 34 - 93 401 65 17

abelcs at cimne.upc.edu

_________________________________________________________


----------------------------------------------------------------------------

De: gidlist-admin at gatxan.cimne.upc.edu [mailto:gidlist-admin at gatxan.cimne.upc.edu] En nombre de Benjamin Sanderse
Enviado el: martes, 21 de noviembre de 2006 23:24
Para: gidlist at gatxan.cimne.upc.es
Asunto: [GiDlist] airfoil mesh



Hello all,



I just started some time ago meshing with GiD. I just have a simple airfoil (2D) in a circular domain.

I want GiD to create a C or O-grid for my geometry. I tried several possibilities, but I could not find a way to generate a good airfoil mesh.

My mesh is always very refined at the leading and trailing edge, but misses refinement near the surface and in the wake.

As wing and airfoil meshing must be a common practice I am wondering if anybody could help me with this.

For convenience I attached my geometry as .gid file.



Thank you so much,



Benjamin


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Benjamin Sanderse

[GiDlist] airfoil mesh

Post by Benjamin Sanderse »

Ok, I see. Problem is that my code needs quads...
----- Original Message -----
From: Enrique Escolano
To: gidlist at gatxan.cimne.upc.edu
Sent: Friday, November 24, 2006 4:36 PM
Subject: Re: [GiDlist] airfoil mesh


As said the error message:

"Quadrilaterals cannot be meshed. All contour lines must have an even number of sides"

You musn't assing an uneven number of divisions to the structured sides (when are connected to the unstructured quadrilaterals).

This is because a subdivision algorithm is used for unstructured quadrilaterals, then the number of subdivisions of its boundary lines
must be multiple of 2.

If you don't assign manually the number of divisions, GiD automatically generate an even number of sides for neighbor entities.

In any case, unstructured quadrilaterals generated by GiD, in general, doesn't have high shape quality.
It's more recommended to use unstructured triangles.

Enrique
----- Original Message -----
From: Benjamin Sanderse
To: gidlist at gatxan.cimne.upc.edu
Sent: Friday, November 24, 2006 8:11 PM
Subject: Re: [GiDlist] airfoil mesh


Hello,

Is it possible to make a transition from an structured quadrilateral mesh (boundary layer) to an unstructured quadrilateral mesh (far field)?
I tried this, but I get the following error:

Quadrilaterals cannot be meshed. All contour lines must have an even number of sides

I even tried it with a simple example of two rectangles that have one side in common, and it doesn't work to put structured quads in the first and unstructured in the second. Please help...

Thank you,

Benjamin

----- Original Message -----
From: Abel Coll
To: gidlist at gatxan.cimne.upc.edu
Sent: Thursday, November 23, 2006 4:43 AM
Subject: RE: [GiDlist] airfoil mesh


Hi,



In relation with the quality of the elements, if your meshes are obtained using Rfast mesher, you can set Rsurf mesher (in Preferences-meshing-Surface mesher) and probably the elements would be better.



ABEL

__________________________________________________________

Abel Coll Sans

CIMNE - International Center for Numerical Methods in Engineering

Office C2 - C1Building - Campus Nord UPC

Gran Capità s/n, 08034 Barcelona

Tfn: 34 - 93 401 74 03 Fax: 34 - 93 401 65 17

abelcs at cimne.upc.edu

_________________________________________________________


--------------------------------------------------------------------------

De: gidlist-admin at gatxan.cimne.upc.edu [mailto:gidlist-admin at gatxan.cimne.upc.edu] En nombre de Benjamin Sanderse
Enviado el: miércoles, 22 de noviembre de 2006 15:54
Para: gidlist at gatxan.cimne.upc.edu
Asunto: Re: [GiDlist] airfoil mesh



Hello,



I did the tutorials and I prescribed the size of the mesh at the boundary of the airfoil. However, that does not give me the expected result: the mesh near the leading and trailing edge is still much finer, and the elements close to the surface look quite bad (in terms of aspect ratio and corner angles).

I tried now to use structured elements instead, but somehow that only works if your surface is the topological equivalent of a rectangle...so that means that I will never be able to create a structured mesh in 2D inbetween an airfoil surface and a boundary?? Sounds strange to me.




Benjamin




On 11/22/06, Abel Coll abelcs at cimne.upc.edu wrote:



Hello Benjamin,



To refine the mesh near any geometrical entity you must assign a prescribed size of the mesh to the entity (Mesh-Unstructured-Assign sizes on.).



I recommend you to do the meshing tutorials available in the web site ( http://www.gidhome.com/support/su05.subst) to be able to take advantage of all the GiD meshing possibilities.



Regards,



ABEL

__________________________________________________________

Abel Coll Sans

CIMNE - International Center for Numerical Methods in Engineering

Office C2 - C1Building - Campus Nord UPC

Gran Capità s/n, 08034 Barcelona

Tfn: 34 - 93 401 74 03 Fax: 34 - 93 401 65 17

abelcs at cimne.upc.edu

_________________________________________________________


--------------------------------------------------------------------------

De: gidlist-admin at gatxan.cimne.upc.edu [mailto:gidlist-admin at gatxan.cimne.upc.edu] En nombre de Benjamin Sanderse
Enviado el: martes, 21 de noviembre de 2006 23:24
Para: gidlist at gatxan.cimne.upc.es
Asunto: [GiDlist] airfoil mesh



Hello all,



I just started some time ago meshing with GiD. I just have a simple airfoil (2D) in a circular domain.

I want GiD to create a C or O-grid for my geometry. I tried several possibilities, but I could not find a way to generate a good airfoil mesh.

My mesh is always very refined at the leading and trailing edge, but misses refinement near the surface and in the wake.

As wing and airfoil meshing must be a common practice I am wondering if anybody could help me with this.

For convenience I attached my geometry as .gid file.



Thank you so much,



Benjamin


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