June 2022 - Nektar-users - imperial.ac.uk

Nektar++ Workshop 2022
by Chris Cantwell 01 Sep '22

01 Sep '22

Dear all, We are planning to hold the next Nektar++ workshop on the 13th-15th September 2022 at Imperial College London. So please save the date! We are finalising the exact timing of the event, but will put more information online soon, including how to register. The event is planned to be primarily an in-person meeting. However, we are, at a minimum, aiming to accommodate viewing of the talks by remote attendees for those unable to travel. We look forward to seeing you in London in September. Kind regards, Chris -- Chris Cantwell Senior Lecturer in Aeronautics Department of Aeronautics Imperial College London South Kensington Campus London SW7 2AZ Tel: +44 (0)20 759 45050 Email: c.cantwell(a)imperial.ac.uk www.imperial.ac.uk/people/c.cantwell

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Mapped boundaries
by Marc Goldbach 11 Aug '22

11 Aug '22

******************* This email 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. ******************* Hi All, I would like to sample data from a plane within my domain (turbulent channel), and use those values as the inlet boundary. The plane at which data is sampled is in the middle of the domain, so a periodic boundary is not suitable. Is this possible, and if so how can I do this? So far I have looked at using the "HistoryPoints" filter to extract data from the simulation along a plane, but I cannot quite figure out how to read the time dependent boundary data from file: 88 <BOUNDARYCONDITIONS> 95 <REGION REF="0"> 96 <D VAR="u" FILE="periodicInlet_"/> 97 <D VAR="v" VALUE="0" /> 98 <D VAR="w" VALUE="0" /> 99 <N VAR="p" USERDEFINEDTYPE="H" VALUE="0" /> 100 </REGION> ... 185 </BOUNDARYCONDITIONS> ... 256 <FILTER TYPE="HistoryPoints"> 257 <PARAM NAME="OutputFile">periodicInlet</PARAM> 258 <PARAM NAME="OutputFrequency">1</PARAM> 259 <PARAM NAME="OutputOneFile">false</PARAM> 260 <PARAM NAME="plane"> 261 100, 100, 262 0, 0, 0, 263 0, 7, 0, 264 0, 0, 2, 265 0, 7, 2 266 </PARAM> 267 </FILTER> When using <PARAM NAME="OutputOneFile">false</PARAM>, the history point data is saved in files based on index (e.g. periodicInlet_0, periodicInlet_1, periodicInlet_2, etc.) Any suggestions are appreciated. Regards, *Marc Goldbach* PhD Student, Department of Mechanical Engineering University of North Carolina at Charlotte

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About the LBB condition
by shan xiangjun 13 Jul '22

13 Jul '22

******************* This email 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: When the continuous or discontinuous Galerkin method is used to solve the incompressible N-S equation, can the “checkerboarding” of the pressure field be avoided if the LBB (or inf-sup) condition is satisfied? Can anyone help me? Thank you very much. Best regards, Shan 从 Windows 版邮件<https://go.microsoft.com/fwlink/?LinkId=550986>发送

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Basic questions as a beginner
by Marc 11 Jul '22

11 Jul '22

******************* This email 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. ******************* Hi everyone, I came across Nektar++ and was very interested in it. As very new to it, I have tons of questions about Nektar++ of which I concerned the most: - The tutorials using Jupyter notebook on the website seem in completed. The mesh files and .xml configuration file are not available in most cases. Any suggestions how to fetch them somewhere else? - I basically play with Incompressible NS flow. Compared with finite volume method, e.g., OPENFOAM and ANSYS FLUENT, how is the efficiency of Nektar++? - Any suggestions how to begin with Nektar++? Marc Ph.D. student

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Parallel FieldConvert output in one single vtu file ?
by Debbahi Saad 15 Jun '22

15 Jun '22

******************* This email 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. ******************* Hi All, I'm on Nektar version 5.1.0, ending with datasets composed of moderate size files in numbers reaching few hundreds using the Incompresible Navier-Stokes Solver, I just want to use parallel FieldConvert to speed up the conversion process (which actually provide a real gain in speed) and produce a single vtu file, since opening *.pvtu format datasets gave an error in paraview-openmpi-5.9.1 , The command I'm using for parallel FieldConvert looks like this: mpirun -n 16 FieldConvert -m mapping model.xml model_i.chk model_i.vtu this creates n .vtu files under a .pvtu header, which as I reported earlier gives rise to this error: > ERROR: In > /builddir/build/BUILD/ParaView-v5.9.1/VTK/IO/XML/vtkXMLPDataReader.cxx, > line 315 > > vtkXMLPUnstructuredGridReader (0x55ffb1431450): File for piece 0 cannot be > read. > Is it possible to produce one single .vtu file out of parallel FieldConvert ? Thanks in advance, any help on this or workaround will be really appreciated, Kind regards, Saad

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Question regarding the compatibility of Ubuntu 22.04 LTS
by 董智康 07 Jun '22

07 Jun '22

******************* This email 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. ******************* Hi, I’m using Ubuntu 22.04 LTS now. I would like to study Nektar++, but I’m not sure if my OS is eligible for Nektar++. If it’s true, how could I install it? Best, Zhikang Dong

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Nektar Floquet Analysis
by Matt Duran 07 Jun '22

07 Jun '22

******************* This email 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. ******************* Hello Nektar users, I have been experiencing some issues running a floquet analysis in Nektar. I was wondering if anyone could send me some files I could use as an example. I have followed the userguide but still have had issues. If I could see some case files for example it would be very helpful. Thanks, Matt Duran

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