Hello Neks, I am trying to simulate the flow around an interpolated airfoil with curved boundaries. To do so I am generating the collocation points separately and writing them into an input file, which is read in the usrdat2 subroutine before geometry re-initialization. The only curved elements in the mesh are located at the airfoil boundary. I am not getting any errors during geometry re-initialization. However, the calculation starts off with a large courant number (around 7), which ends up diverging after 5 times steps. Along the element edges near the airfoil, there seems to be discontinuities in the flow which cause the solution to diverge. However, when inputting non-curvilinear collocation points, written in the exact same order to the input file, the simulation runs flawlessly. Are there any switches that must be activated in the rea file for curved elements? If not, are there any general guidelines to using curved elements in this manner? Thanks, Jeremie
Hi Jeremie, Try calling "fix_geom" in usrdat2 after you modify the sides... this might provide the requisite mesh clean up. Paul ________________________________ From: [email protected] [[email protected]] on behalf of [email protected] [[email protected]] Sent: Sunday, October 26, 2014 4:10 PM To: [email protected] Subject: [Nek5000-users] Curved GLL Points on Airfoil Hello Neks, I am trying to simulate the flow around an interpolated airfoil with curved boundaries. To do so I am generating the collocation points separately and writing them into an input file, which is read in the usrdat2 subroutine before geometry re-initialization. The only curved elements in the mesh are located at the airfoil boundary. I am not getting any errors during geometry re-initialization. However, the calculation starts off with a large courant number (around 7), which ends up diverging after 5 times steps. Along the element edges near the airfoil, there seems to be discontinuities in the flow which cause the solution to diverge. However, when inputting non-curvilinear collocation points, written in the exact same order to the input file, the simulation runs flawlessly. Are there any switches that must be activated in the rea file for curved elements? If not, are there any general guidelines to using curved elements in this manner? Thanks, Jeremie
Hi Paul, I tried calling fix_geom in usrdat2 and it did not fix the problem. Jérémie On Sunday, October 26, 2014, <[email protected]> wrote:
Hi Jeremie,
Try calling "fix_geom"
in usrdat2 after you modify the sides... this might provide the requisite mesh clean up.
Paul
------------------------------ *From:* [email protected] <javascript:_e(%7B%7D,'cvml','[email protected]');> [[email protected] <javascript:_e(%7B%7D,'cvml','[email protected]');>] on behalf of [email protected] <javascript:_e(%7B%7D,'cvml','[email protected]');> [ [email protected] <javascript:_e(%7B%7D,'cvml','[email protected]');>] *Sent:* Sunday, October 26, 2014 4:10 PM *To:* [email protected] <javascript:_e(%7B%7D,'cvml','[email protected]');> *Subject:* [Nek5000-users] Curved GLL Points on Airfoil
Hello Neks,
I am trying to simulate the flow around an interpolated airfoil with curved boundaries. To do so I am generating the collocation points separately and writing them into an input file, which is read in the usrdat2 subroutine before geometry re-initialization. The only curved elements in the mesh are located at the airfoil boundary. I am not getting any errors during geometry re-initialization. However, the calculation starts off with a large courant number (around 7), which ends up diverging after 5 times steps. Along the element edges near the airfoil, there seems to be discontinuities in the flow which cause the solution to diverge. However, when inputting non-curvilinear collocation points, written in the exact same order to the input file, the simulation runs flawlessly.
Are there any switches that must be activated in the rea file for curved elements?
If not, are there any general guidelines to using curved elements in this manner?
Thanks,
Jeremie
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