[zhengjg]

Hello friends,
I have a problem on the specification of periodic boundary conditions in SU2.

I am using SU2 6.2 to simulate an 3D external flow around a 2D wing.

The spanwise direction is in z direction.

A 3D C-type grid is used, which is generated by translating a 2D mesh in x-y plane in z direction with uniform spanwise grid spacing.

On the front and back surface of the resulting 3D mesh that are normal to z axis, the peridoic boundary (BC) conditions should be imposed.

My question is: how can I specify the peridoic BC?

According to the template configuration file, the peridoic BCshould be specified in the following way:

% Periodic boundary marker(s) (NONE = no marker)
% Format: ( periodic marker, donor marker, rotation_center_x, rotation_center_y,
% rotation_center_z, rotation_angle_x-axis, rotation_angle_y-axis,
% rotation_angle_z-axis, translation_x, translation_y, translation_z, ... )
MARKER_PERIODIC= ( ... )


But I do not understand the physical meaning of the above parameters.
It would be greatly appreciate if anyone can help me resolve this problem.

[nitish_anand]

Originally Posted by zhengjg

Hello friends,
I have a problem on the specification of periodic boundary conditions in SU2.

I am using SU2 6.2 to simulate an 3D external flow around a 2D wing.

The spanwise direction is in z direction.

A 3D C-type grid is used, which is generated by translating a 2D mesh in x-y plane in z direction with uniform spanwise grid spacing.

On the front and back surface of the resulting 3D mesh that are normal to z axis, the peridoic boundary (BC) conditions should be imposed.

My question is: how can I specify the peridoic BC?

According to the template configuration file, the peridoic BCshould be specified in the following way:

% Periodic boundary marker(s) (NONE = no marker)
% Format: ( periodic marker, donor marker, rotation_center_x, rotation_center_y,
% rotation_center_z, rotation_angle_x-axis, rotation_angle_y-axis,
% rotation_angle_z-axis, translation_x, translation_y, translation_z, ... )
MARKER_PERIODIC= ( ... )


But I do not understand the physical meaning of the above parameters.
It would be greatly appreciate if anyone can help me resolve this problem.

Hey Jianguo,

I have only used Periodic Boundary for turbomachinery simulations and should not be much different for your case.

Use the following format

MARKER_PERIODIC = (front_marker, back_marker, 0,0,0,0,0,0, translation_x, translation_y, translation_z)

where front_marker and back_marker are your Mesh Markers. And rest defines where the doner markers lie with respect to the receiver marker. So if you have rotation you specify them in place of <0,0,0,0,0,0> but in your case, you want in terms of translation so you specify <translation_x, translation_y, translation_z>.

This should solve your problem.

Remember that you have to do SU2_PER to obtain the mesh with SEND RECEIVE marker and then run SU2_CFD to run CFD.

Thanks
Nitish

[zhengjg]

Hi Nitis,
Thank for your help.
I have implement the periodic BC with your method.

An update is that in SU2 6.2, the SU2_MSH is used to generate the new mesh with periodic BC setting.

JG

[nitish_anand]

Indeed !!

I am still using some older version hence SU2_PER.

Glad that you figured it out already.

Cheers,
Nitish