About Symmetric Boundary Condition in 3D Simulation
******************* This email originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list https://spam.ic.ac.uk/SpamConsole/Senders.aspx to disable email stamping for this address. ******************* Dear Nektar++ users and developers: Sorry to bother everyone here, however, I need some help with boundary condition setting in the IncNS solver. My case is a 3D model with xz-symmetric plane: 1. Is there a boundary condition of symmetry surfaces in Nektar++ IncNS solver (such as symmetry boundary in Ansys Fluent), and is there an alternative scheme (if xz-plane is the symmetric plane how could I properly set [u v w p] bc-vector on the y=0 mid-plane? Neumann u=0, Dirichlet v=0, Neumann w=0, Dirichlet p=0?) 2. If there is a boundary condition such as a symmetry surface, whether the flow field of the full-model can be generated from the half-model fld files utilizing the FieldConvert tool. Could it be reliably implemented using pointwise file (calculate the half-mode (if possible), write out the DAT (tecplot) file, write the data symmetrically to a pointwise file, and then write the full-mode mesh)? Thank you for your help and look forward to your discussion and response. Thanks to the Nektar++ project team. Best Regards, Wang Zhouyang
Dear Wang, No problems at all: 1. The incompressible symmetry BCs may only be applied to cases with flat surfaces. Here is an example of a 3D x-z symmetry plane set of conditions: <N VAR="u" VALUE="0"/> <D VAR="v" VALUE="0"/> <N VAR="w" VALUE="0"/> <N VAR="p" VALUE="0"/> 1. I am not quite sure I understand your question. Do you want to reflect around the symmetry plane? Normally I convert the solution to csv, mirror it in Python and interpolate it to a mesh of the complete domain. Is that what you are asking? Thanks, Guglielmo ________________________________ From: nektar-users-bounces@imperial.ac.uk <nektar-users-bounces@imperial.ac.uk> on behalf of 王舟阳 <wangzhouyang@buaa.edu.cn> Sent: 29 March 2023 17:46 To: nektar-users <nektar-users@imperial.ac.uk> Subject: [Nektar-users] About Symmetric Boundary Condition in 3D Simulation This email from wangzhouyang@buaa.edu.cn originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list<https://spam.ic.ac.uk/SpamConsole/Senders.aspx> to disable email stamping for this address. Dear Nektar++ users and developers: Sorry to bother everyone here, however, I need some help with boundary condition setting in the IncNS solver. My case is a 3D model with xz-symmetric plane: 1. Is there a boundary condition of symmetry surfaces in Nektar++ IncNS solver (such as symmetry boundary in Ansys Fluent), and is there an alternative scheme (if xz-plane is the symmetric plane how could I properly set [u v w p] bc-vector on the y=0 mid-plane? Neumann u=0, Dirichlet v=0, Neumann w=0, Dirichlet p=0?) 2. If there is a boundary condition such as a symmetry surface, whether the flow field of the full-model can be generated from the half-model fld files utilizing the FieldConvert tool. Could it be reliably implemented using pointwise file (calculate the half-mode (if possible), write out the DAT (tecplot) file, write the data symmetrically to a pointwise file, and then write the full-mode mesh)? Thank you for your help and look forward to your discussion and response. Thanks to the Nektar++ project team. Best Regards, Wang Zhouyang
Hi Zhouyang, 1. There is no symmetry boundary in Nektar++. You need to assign a proper boundary condition for each variable. In your case, you need Neumann u=0; Dirichelet v=0; Nuemann w=0; Neumann p=0 on the y=0 plane. 2. This feature is not implemented, either. But you can do this in tecplot. Cheers Ankang -----Original Messages----- From:"王舟阳" <wangzhouyang@buaa.edu.cn> Sent Time:2023-03-30 00:46:34 (Thursday) To: nektar-users@imperial.ac.uk Cc: Subject: [Nektar-users] About Symmetric Boundary Condition in 3D Simulation | This email from wangzhouyang@buaa.edu.cn originates from outside Imperial. Do not click on links and attachments unless you recognise the sender. If you trust the sender, add them to your safe senders list to disable email stamping for this address. | Dear Nektar++ users and developers: Sorry to bother everyone here, however, I need some help with boundary condition setting in the IncNS solver. My case is a 3D model with xz-symmetric plane: 1. Is there a boundary condition of symmetry surfaces in Nektar++ IncNS solver (such as symmetry boundary in Ansys Fluent), and is there an alternative scheme (if xz-plane is the symmetric plane how could I properly set [u v w p] bc-vector on the y=0 mid-plane? Neumann u=0, Dirichlet v=0, Neumann w=0, Dirichlet p=0?) 2. If there is a boundary condition such as a symmetry surface, whether the flow field of the full-model can be generated from the half-model fld files utilizing the FieldConvert tool. Could it be reliably implemented using pointwise file (calculate the half-mode (if possible), write out the DAT (tecplot) file, write the data symmetrically to a pointwise file, and then write the full-mode mesh)? Thank you for your help and look forward to your discussion and response. Thanks to the Nektar++ project team. Best Regards, Wang Zhouyang -- Research Associate Department of modern mechanics University of Science and Technology of China
participants (3)
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ankanggao＠ustc.edu.cn
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Vivarelli, Guglielmo A
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王舟阳