February 2024 - Nektar-users

Issue with compressible flow solver
by Octavio Morales 26 Feb '24

26 Feb '24

******************* 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 am having some trouble with the compressible flow solver when I run the attached case. I am attaching the .xml file and the .out file This is the error I am getting and don't know how to solve it: Warning : Level 0 assertion violation # Nonlinear solver not converge in DoImplicitSolve * Newton-Its converged (RES=-nan Res/(DtRHS): -nan with 10 Non-Its) Steps: 672 Time: 6.72000e-01 CPU Time: 10.604s Fatal : Level 0 assertion violation NaN found during time integration. Fatal : Level 0 assertion violation NaN found during time integration. Fatal : Level 0 assertion violation NaN found during time integration. Fatal : Level 0 assertion violation NaN found during time integration. -------------------------------------------------------------------------- Primary job terminated normally, but 1 process returned a non-zero exit code. Per user-direction, the job has been aborted. -------------------------------------------------------------------------- -------------------------------------------------------------------------- mpirun detected that one or more processes exited with non-zero status, thus causing the job to be terminated. The first process to do so was: Process name: [[52564,1],2] Exit code: 1 -------------------------------------------------------------------------- Any Help or comment will be extremely appreciated. Kind regards, Octavio Morales. U-MOFABI, Facultad de Ingeniería UNAM

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Issue with compressible flow solver.
by Octavio Morales 25 Feb '24

25 Feb '24

******************* 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 am having some trouble with the compressible flow solver when I run the attached case. I am attaching the .xml file and the .out file This is the error I am getting and don't know how to solve it: Warning : Level 0 assertion violation # Nonlinear solver not converge in DoImplicitSolve * Newton-Its converged (RES=-nan Res/(DtRHS): -nan with 10 Non-Its) Steps: 672 Time: 6.72000e-01 CPU Time: 10.604s Fatal : Level 0 assertion violation NaN found during time integration. Fatal : Level 0 assertion violation NaN found during time integration. Fatal : Level 0 assertion violation NaN found during time integration. Fatal : Level 0 assertion violation NaN found during time integration. -------------------------------------------------------------------------- Primary job terminated normally, but 1 process returned a non-zero exit code. Per user-direction, the job has been aborted. -------------------------------------------------------------------------- -------------------------------------------------------------------------- mpirun detected that one or more processes exited with non-zero status, thus causing the job to be terminated. The first process to do so was: Process name: [[52564,1],2] Exit code: 1 -------------------------------------------------------------------------- Any Help or comment will be extremely appreciated. Kind regards, Octavio Morales. U-MOFABI, Facultad de Ingeniería UNAM

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NACA0012 @ M=0.8 file
by Octavio Morales 21 Feb '24

21 Feb '24

******************* 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 dear Nektar++ community. I am quite new with the Nektar software, I'm mainly working with compressible flows at high high subsonic, transonic and supersonic regimes. After reading the compressible flow solver section I noticed the case of a NACA0012 profile @ M=0.8, I looked for the file in the tutorial section but it's not there. ¿Is there any chance that you guys please share the .xml file that outcomes that exact same solution? Any information will be highly appreciated! Have a nice day, Octavio Morales U-MOFABI Facultad de Ingeniería UNAM

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new driver
by Ata ollah Mesgarnejad 20 Feb '24

20 Feb '24

******************* 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 new to this community and appreciate your help. I'd like to know if I can create a driver that runs the time integration scheme for a single time step. I can see that I can set the number of steps, but there's no setter for the final time. Thank you, Ata

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Question about restart file in Time-averaged fields filter
by 王舟阳 19 Feb '24

19 Feb '24

******************* 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 Nektar++ users and developers: Hi, everyone, I am sorry to disturb. My question is about the calculation of the "Time-averaged fields" in filters. One of the input options is: "RestartFile", how should I use this option correctly? For example: I have five checkpoints such as s_1.chk, s_2.chk, s_3.chk, s_4.chk, s_5.chk, and their time-mean field s_avg.fld, besides the final output file s.fld. Then, I want to continue my simulation, so I write s.fld as the initial condition function (in <FUNCTION NAME="InitialConditions">). At this time, I hope to use s_avg.fld as the restart file (in <PARAM NAME="RestartFile">s_avg.fld</PARAM>) of the time-average field filter to reduce the time consumption of the entire simulation process by utilizing all the results obtained. I would like to ask users and developers whether I understand RestartFile option correctly (might it be used to take the original time-average field as the first snapshot in my process)? How could I correctly fill the filter section of the xml document. Thank you very much and look forward to your reply. Best Regards, Wang Zhouyang

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FieldConvert fails to read Nek5000 output files
by Ajeesh Mohan T 16 Feb '24

16 Feb '24

******************* 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 nektar-users, I am trying to obtain tecplot readable formats from some Nek5000 outputs I already have; using the FieldConvert utility available in Nektar++ (It also supports the reading of data files from Nek5000 as claimed in the user guide). The command given to convert the nek5000 outputs to Nektar++ outputs is as follows; FieldConvert input.fld output.fld However, the output format (ASCII) of nek5000 is actually .fld followed by some numbers indicating the timesteps. The output for each timestep is written separately. FieldConvert fails to identify this format and listed the supported formats as .fld or .fld5000 while the second one is given specifically to read the Nek5000 outputs. I am not sure whether this is an old format of nek5000; anyway I did not find any information about this format online. I would like to kno if anyone tried this or have an idea whether FieldConvert still supports Nek5000 output files or not. Any help will be deeply appreciated. Thank you in advance. *Warm regards,* *Ajeesh Mohan T,* *Doctoral Research Scholar,* *IIT Bombay, Mumbai, India.*

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FieldConvert: command not found
by Ajeesh Mohan T 13 Feb '24

13 Feb '24

******************* 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 nektar-users, I am new to Nektar++ and just installed it in my Ubuntu 22.04 by compiling from the source obtained from GitHub as instructed in the user guide. The installation was successful without any errors and I tested it using *ctest* command where all of the 760 test cases passed successfully (screenshot is attached). My primary objective is to obtain tecplot readable formats from some Nek5000 outputs I already have; using the FieldConvert utility (It also supports the reading of data files from Nek5000 as claimed in the user guide). However, the problem I am encountering is that the terminal does not recognize the *FieldConvert* command. I am not able to find the issue anywhere on the internet. It will be very helpful if any of you can help me with this. Thank you in advance. *Warm regards,* *Ajeesh Mohan T,* *Doctoral Research Scholar,* *IIT Bombay, Mumbai, India.* [image: Nektar++_test.png]

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Issues with compilation
by Nico Clinco 08 Feb '24

08 Feb '24

******************* 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, Recently, i tried to compile nektar++ with mpi. And i'm facing some issues with the compilation. The problem seems to be that "MPI_SEND" is not found as shown in the figure. Therefore, when i try to launch my applications on multiple nodes on an HPC cluster i have problems. If someone can help me i will be glad. Thank you in advance, Nicola

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FieldConvert range option
by Selman BAYSAL 04 Feb '24

04 Feb '24

******************* 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 I try to run the FieldConvert range option in parallel (e.g., mpirun -np FieldConvert -r x1,x2,y1,y2 turb.xml turb.fld turb.plt) it gives the&nbsp;segmentation fault. This post-process takes a long time in serial run. Is there any point I'm missing? Many thanks in advance.Selman BaysalR. A. in HydraulicsDept. of Civil Eng'gÇanakkale Onsekiz Mart University--ITU Civil Eng., BSc.ITU Coastal Sci. &amp; Eng., MSc.

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Save the date - Nektar++ Workshop 2024
by Mohsen Lahooti 02 Feb '24

02 Feb '24

******************* 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, I am excited to inform you that the next Nektar++ workshop will be at Newcastle University during 11-13 June 2024 Please save the dates, I will be in touch with more details soon. Cheers, Mohsen Dr Mohsen Lahooti, PhD Lecturer in Fluid-Structure interaction Mechanical Engineering Newcastle University School of Engineering Room 4.28, Stephenson Building Claremont Road Newcastle-Upon-Tyne NE1 7RU United Kingdom Email: mohsen.lahooti(a)newcastle.ac.uk<mailto:mohsen.lahooti@newcastle.ac.uk> Webpage<https://www.ncl.ac.uk/engineering/staff/profile/mohsenlahooti.html>

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