[Nek5000-users] Pipe with expansion

[nek5000-users at lists.mcs.anl.gov]

Hi Kamal,

For the geometry you describe, I would apply mesh morphing
to a standard straight pipe.  You can create such a pipe
using a subset of the mkmesh script provided in the expansion
example.

If your transition region is conical, then I woud make
certain that the change in slope occurs at element boundaries,
i.e., as in the half cross-section depicted below:

                               _______________
                              /|      |      |
                            /  |      |      |
                          /|   |      |      |
        ________________/  |   |      |      |
        |     |     |   |  |   |      |      |
        |     |     |   |  |   |      |      |
        +-----+-----+---+--+---+------+------+---->  z


Paul



On Wed, 15 Jan 2014, nek5000-users at lists.mcs.anl.gov wrote:

> Hi Paul,
>
> I looked at the example and it looks very helpful, but for a sudden expansion 
> we have only two parts (i.e) the inlet pipe and the outlet pipe. Whereas in a 
> diverging pipe we have three section (i.e,) The inlet pipe, Diverging section 
> and the outlet pipe.
>
>
> Is it possible for me to create a 2D diverging section using mesh 
> modification and revolve it around the centre axis to get a 3d diverging pipe 
> ?
>
>
> or should I apply the mesh modification directly to the 3d sudden expansion 
> pipe using usrdat2() ?
>
> Thanks,
> Kamal
>
>
> On 14/01/2014 21:09, nek5000-users at lists.mcs.anl.gov wrote:
>> Hi Paul,
>> 
>> Thanks a lot for the update. I will take a look at as soon as possible and 
>> keep you updated with it.
>> 
>> Thank you,
>> 
>> Kamal
>> 
>> On Jan 14, 2014, at 9:04 PM, nek5000-users at lists.mcs.anl.gov wrote:
>> 
>>> Kamal,
>>> 
>>> I've added an example for a step-type expansion in a pipe.  New example 
>>> directory
>>> is nek5_svn/examples/expansion, with a README.
>>> 
>>> If you want a standard diffuser, I would use mesh-morphing, as outlined in 
>>> the
>>> nek primer, which can be found on this page:
>>> 
>>> http://nek5000.mcs.anl.gov/index.php/UG#Documentation
>>> 
>>> I've also automated our turbulent outflow bc treatment -- one simply 
>>> provides an
>>> expansion factor (typically ~ 1.5) and two persistent arrays to 
>>> turb_outflow(), which
>>> is now in navier5.f.    This can be useful when very strong vortices are 
>>> leaving the
>>> domain, which is possible for certain diffuser flow conditions (and 
>>> others).
>>> 
>>> Paul
>>> ________________________________________
>>> From: nek5000-users-bounces at lists.mcs.anl.gov 
>>> [nek5000-users-bounces at lists.mcs.anl.gov] on behalf of 
>>> nek5000-users at lists.mcs.anl.gov [nek5000-users at lists.mcs.anl.gov]
>>> Sent: Monday, January 13, 2014 3:35 AM
>>> To: nek5000-users at lists.mcs.anl.gov
>>> Subject: [Nek5000-users] Creating a Mesh
>>> 
>>> Hi
>>> 
>>> Can some one please help me in this because I am new to nek
>>> 
>>> 1) How can I create a .rea for a specific geometry say ' A sudden
>>> expansion pipe ' or a ' Diverging pipe '
>>> 
>>> 2) What tool I should use to create that mesh.
>>> 
>>> 
>>> Thank you
>>> 
>>> 
>>> kamal
>>> _______________________________________________
>>> Nek5000-users mailing list
>>> Nek5000-users at lists.mcs.anl.gov
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