November 2018 - Nektar-users

Mapping Variables from Different Solvers
by Khaled Younes 09 Nov '18

09 Nov '18

Hello, I am trying to map variables from the CompressibleFlowSolver to the baseflow in APESolver for a coupled simulation that I am running. I was successfully able to map the pressure and density using: ‘<F VAR="p0" FILE="File.fld:p" />’ ‘<F VAR="rho0" FILE="File.fld:rho" />’ However, the same syntax does not apply for the velocity field, as the CompressibleFlowSolver solves for the momentum directly: ‘rhou, rhov’. Is there a way I can convert these variables to ‘u,v’ by dividing by the density? Thanks, Khaled Younes

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Re: [Nektar-users] FW: Nektar++ installation in a cluster
by Amitvikram Dutta 05 Nov '18

05 Nov '18

Hi Nitish, Did you turn off the BUILD_THIRDPARTY options on the ccmake screen? I had a similar problem. I placed a ThirdParty folder containing the tarballs of all the thirdparty dependencies in the NEKTAR_SRC directory (which contains the build dir) and turned off the options that I mentioned above. That worked for me. Sincerely, On Tue, Oct 30, 2018 at 9:23 AM Amitvikram Dutta < amitvikram.dutta(a)uwaterloo.ca> wrote: > > ------------------------------ > *From:* nektar-users-bounces(a)imperial.ac.ukOn Behalf OfNitish Arya > *Sent:* October 30, 2018 8:21:04 AM (UTC-05:00) Eastern Time (US & Canada) > *To:* nektar-users(a)imperial.ac.uk > *Subject:* [Nektar-users] Nektar++ installation in a cluster > > Hello. > > I am planning to use APE solver included in the nektar framework. I have > to configure the MPI using Intel MPI which is available in the cluster, > while dependencies are installed using an internet connection. The internet > connection is only available at the head node in which I am unable to > invoke the Intel MPI. So it means that I have to compile the dependencies > separately. I tried compiling the ThirdParty dependencies separately but > when I compiled Nektar, it was again searching for the dependencies via > http or https ( both of the protocols are also not working ). > > Is there any way I can install Nektar without the installer searching for > the dependencies in the internet. > > > Sincerely, > Nitish > -- *Amitvikram Dutta* Graduate Research Assistant Fluid Mechanics Research Lab Multi-Physics Interaction Lab University of Waterloo

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Re: [Nektar-users] FW: Questions regarding APE Solver
by Amitvikram Dutta 04 Nov '18

04 Nov '18

Thanks a lot Killian, Is there a tentative release date for Nektar 5? On Fri, Oct 26, 2018, 3:58 AM Amitvikram Dutta < amitvikram.dutta(a)uwaterloo.ca> wrote: > > > > ________________________________________ > From: nektar-users-bounces(a)imperial.ac.ukOn Behalf OfKilian Lackhove > Sent: October 26, 2018 3:58:07 AM (UTC-05:00) Eastern Time (US & Canada) > To: Amitvikram Dutta; nektar-users > Subject: Re: [Nektar-users] Questions regarding APE Solver > > Hi Amitvikram, > > 1. Yes, only the lamb vector was used, so the RHS of the pressure > equation is zero. > > 2. It seems the userguide is out of date. In Nektar++ 4.4 the RHS are > specified using forcings (see the userguide). See e.g. > APE_2DPulseAdv_WeakDG_MODIFIED.xml example how this is set up in the xml > file. In short, you would have something like this: > > <CONDITIONS> > ... > <FUNCTION NAME="Source"> > <E VAR="p" VALUE="0"/> > <E VAR="u" VALUE="define lamb vector here"/> > <E VAR="v" VALUE="define lamb vector here"/> > <E VAR="w" VALUE="define lamb vector here"/> > </FUNCTION> > </CONDITIONS> > <FORCING> > <FORCE TYPE="Field"> > <FIELDFORCE> Source <FIELDFORCE/> > </FORCE> > </FORCING> > > 3. The next Nektar++ major release will ship a fieldfromstring module, > which should be able to compute the source terms without the pts detour. > Until then you can just use "FieldConvert foo.xml foo.chk bar.pts" to > obtain a pts file with the values at the quadrature points. > > In general, Nektar++ 5.0.0 will contain many changes and improvements to > the acoustics solver, in particular with regard to hybdrid CAA > cosimulations, so you might want to give it a try once its released. > > Cheers, > > Kilian > > > Am 26.10.18 um 04:55 schrieb Amitvikram Dutta: > > Hi everyone, > > > > I'm trying to use the APE Solver in nektar++ to predict sound generation > > from a particular industrial flow. The work is similar in scope to that > > published in this recent paper : > > http://www.iccfd.org/iccfd10/papers/ICCFD10-248-Paper.pdf. > > I'm particularly interested in how to define the source term. If I > > understand the work correctly, in a flow dominated by coherent > > structures, the Lamb vector becomes the dominant source. > > This leads to my first question : > > 1.In the APE-4 formulation there are 2 coupled equations with seperate > > source terms - one for the pressure fluctuations and one for the > > velocity fluctuations. In the above paper when the authors state that > > only the lamb vector was considered as a source, was the source for the > > RHS of the pressure fluctuations set to zero? > > 2. If this was the case, how was this specified in the .xml file? The > > only example I have come across is in the user guide which shows > > > > <FUNCTION NAME="Source"> > > <E VAR="S" VALUE="0" /> > > </FUNCTION> > > > > If one wanted to specify the pressure and velocity source terms > > seperately how would one do it in the .xml file? > > > > 3. From older posts in the mailing list I have seen suggestions of a > > workflow where the .chk/.fld files are written into a .pts file and then > > post processed to obtain the acoustic source. Is there a relevant filter > > or an extension the FieldConvert module that allows direct conversion > > from a .fld/.chk to a .pts format? I know of the interppoints extension > > that allows export to a .dat format but not the .pts? > > > > Sorry for the lengthy post. > > Thanks in advance! > > -- > > > > *Amitvikram Dutta* > > > > Graduate Research Assistant > > > > Fluid Mechanics Research Lab > > > > Multi-Physics Interaction Lab > > > > University of Waterloo > > > > > > _______________________________________________ > > Nektar-users mailing list > > Nektar-users(a)imperial.ac.uk > > https://mailman.ic.ac.uk/mailman/listinfo/nektar-users > > > > -- > Dr.-Ing. Kilian Lackhove > Fachgebiet für Energie- und Kraftwerkstechnik > L1|08 114 > Technische Universität Darmstadt > Otto-Berndt-Straße 3 > D-64287 Darmstadt > Germany > > Tel.: +49 6151 16 - 28915 > Fax: +49 6151 16 - 6555 > e-mail: lackhove(a)ekt.tu-darmstadt.de > > _______________________________________________ > Nektar-users mailing list > Nektar-users(a)imperial.ac.uk > https://mailman.ic.ac.uk/mailman/listinfo/nektar-users > -- *Amitvikram Dutta* Graduate Research Assistant Fluid Mechanics Research Lab Multi-Physics Interaction Lab University of Waterloo

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