Dear Stanislaw, (Oops, sorry incomplete message sent by error!) I was thinking of experimenting it by defining a narrow band of quads, assigning them to a composite to define a boundary and using it as an inlet, with a time dependent velocity profile, But if I intend to mimic the fluid blowing inside the channel it would require adding "fluid flux" through the active cells not only imposing, say, a normal fluid velocity over the blowing strip ie. ideally "injecting fluid" via a velocity inlet type Boundary condition, I hope you get a sense of the subtlety I hardly am trying to detail here. ideally fluid injection-mass flux Vs. imposed velocity profile at the wall strip Any comment or suggestion on the above aspect ? Thanks in advance, with gratitude, Saad Le mer. 6 juil. 2022 à 21:15, Debbahi Saad <saad.debbahi@gmail.com> a écrit :

Dear Stanislaw,

I was thinking of experimenting it by defining a narrow band of quads assign them to a

Le mer. 6 juil. 2022 à 01:41, Stanislaw Gepner <stanislaw.gepner@pw.edu.pl> a écrit :

...

Dear Saad,

You could experiment with the boundary conditions and applying it either from file or as an equation. If your case is fully 3D (not homogeneous expansion) you could design the mesh to have the ability to set required conditions only to the regions you choose. Cheers, Stan

<http://www.pw.edu.pl/> On 06.07.2022 00:54, Debbahi Saad wrote:

This email from saad.debbahi@gmail.com 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 all,

I use Nektar++ mainly to study time dependent 3D plane Poiseuille flow, using the Incompressible Navier-Stokes Solver (using a fully 3D configuration), I'm wondering what would be the best approach to add Blowin and/or Suction at the wall ? Looking into the user-guide version 5.1.0 section 3.5.1- XML-Session-File>Forcing>Absorption seems to be a usable feature in this context Is there an efficient and suitable approach to add these perturbations to the flow ?

Any general guidelines to achieve this are really appreciated,

Thanks in advance,

Kind regards,

Saad

_______________________________________________ Nektar-users mailing listNektar-users@imperial.ac.ukhttps://mailman.ic.ac.uk/mailman/listinfo/nektar-users

_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users

Dear Saad, I think I see your point. You would like to not sett the profile, but rather let it adjust to the surrounding flow. Have you considered setting Neuman conditions on velocity and fix the pressure with a Direchlet? Not exactly what you describe, but this is one way I would explore. You could also try with USERDEFINEDTYPE="HOutflow" and set a non-zero value to velocity components (see 11.1.4 of the Guide). But some care would need to be taken, as what exactly is the meaning of what you set. Cheers! Stan On 07.07.2022 05:32, Debbahi Saad wrote:

Dear Stanislaw,

(Oops, sorry incomplete message sent by error!)

        I was thinking of experimenting it by defining a narrow band of quads, assigning them to a composite to define a boundary and using it as an inlet, with a time dependent velocity profile,        But if I intend to mimic the fluid blowing inside the channel it would require adding "fluid flux" through the active cells not only imposing, say, a normal fluid velocity over the blowing strip ie. ideally "injecting fluid" via a velocity inlet type Boundary condition, I hope you get a sense of the subtlety I hardly am trying to detail here. ideally fluid injection-mass flux Vs. imposed velocity profile at the wall strip

      Any comment or suggestion on the above aspect ?

Thanks in advance,

with gratitude,

Saad

Le mer. 6 juil. 2022 à 21:15, Debbahi Saad <saad.debbahi@gmail.com> a écrit :

Dear Stanislaw,

        I was thinking of experimenting it by defining a narrow band of quads assign them to a

Le mer. 6 juil. 2022 à 01:41, Stanislaw Gepner <stanislaw.gepner@pw.edu.pl> a écrit :

Dear Saad,

You could experiment with the boundary conditions and applying it either from file or as an equation. If your case is fully 3D (not homogeneous expansion) you could design the mesh to have the ability to set required conditions only to the regions you choose.

Cheers, Stan

On 06.07.2022 00:54, Debbahi Saad wrote:

...

This email from saad.debbahi@gmail.com 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 all,

           I use Nektar++ mainly to study time dependent 3D plane Poiseuille flow, using  the Incompressible Navier-Stokes Solver (using a fully 3D configuration), I'm wondering what would be the best approach to add Blowin and/or Suction at the wall ? Looking into the user-guide version 5.1.0 section 3.5.1- XML-Session-File>Forcing>Absorption seems to be a usable feature in this context Is there an efficient and suitable approach to add these perturbations to the flow ?

           Any general guidelines to achieve this are really appreciated,

Thanks in advance,

Kind regards,

Saad

_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users

_______________________________________________ Nektar-users mailing list Nektar-users@imperial.ac.uk https://mailman.ic.ac.uk/mailman/listinfo/nektar-users