[Paraview] How to plot Surface StreamLines

[Richard GRENON]

Berk Geveci wrote:
> Hi Richard,
>
> If you have an example dataset you can share, I would like to play
> around a bit. The reason the streamlines are terminating prematurely
> is because streamlines are leaving the surface because of integration
> inaccuracy. Making sure that all of the velocity values are tangential
> to the surface would help but not necessarily fix the issue. What
> needs to happen is a change in the algorithm that move the points back
> to the surface when integration along the surface. I know someone who
> has done this in the past. I'll check with him to see if he would
> contribute his changes.
>
> -berk
>
> On Fri, Apr 10, 2009 at 5:35 AM, Richard GRENON <richard.grenon at onera.fr> wrote:
>   
>
Hi Berk,

My dataset is an Euler velocity field at the surface of an aircraft, so 
it's everywhere tangent to the surface. But the grid refinement is 
really an important parameter. The forebody has almost a constant 
section in the area where I put the seed points, but the mesh is coarse 
in the aircraft axis direction in this area, and the surface streamlines 
stop after crossing one or two cells. But at the wing root, the grid is 
well refined in all directions and I can obtain fuselage streamlines 
crossing many cells on a distance covering more than the wing root chord.

I am sorry but the datasets I am working on cannot be shared. But you 
can try the example for Custom filters in 
http://www.paraview.org/Wiki/Custom_Filters. The dataset is the 
disk_out_ref.ex2 from Sc07_paraview_tutorial_data.tar.gz.
In this example surface streamlines are plotted on a slice plane and I 
tried to replace the slice plane by a slice sphere. Of course this is 
not a good example as the vectors are not tangent to the plane or to the 
sphere before applying the "Surface Vectors" filter, but it works with a 
plane.

I agree with you concerning the fact that the point sould be moved back 
to the surface at each step of the integration. If such an improvement 
of the surface streamlines computation could be added in a future 
Paraview release, it would be really a nice feature. I am always keeping 
an eye on Paraview.

Best regards,

-- 
 Richard GRENON
 ONERA
 Departement d'Aerodynamique Appliquee - DAAP/ACI
 8 rue des Vertugadins
 92190 MEUDON - FRANCE
 phone : +33 1 46 73 42 17
 fax   : +33 1 46 73 41 46
 mailto:Richard.Grenon at onera.fr
 http://www.onera.fr