April 2021 - Nektar-users - imperial.ac.uk

Apply filer to a specified domain range
by Stanisław Gepner 03 May '21

03 May '21

******************* 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 was wandering if it is possible to program into a Filter a possibility to be applied onto a selected range of the domain. Much like what is possible using FieldConvert -r option. I looked at the code, and there is the DomainRange, but I am not sure there is a way to use it on ExpList through which I access coordinates, physical values from within the Filter. One solution I see is to just go through what is available through GetCoords() (at initialization) and create a mask to filter out values from outside the specified range. The filter I am working on is based on quantities integrated from the fields, So I think I could create the mask at initialization and than use it at updates to zero-out values outside. But might it be, that something like this is already implemented? Any suggestions are welcome. Cheers! Stan -- Best regards, Stanisław Gepner, Ph.D. *Faculty of Power and Aeronautical Engineering* Nowowiejska 21/25 Str. 00-665 Warsaw, Poland phone +48 (22) 234 51 70 <https://www.pw.edu.pl/engpw>

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Post-processing - Wall Shear Stress
by Paulo henrique Ferreira 03 May '21

03 May '21

******************* 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 ran a typical simulation of a circular cylinder at Re = 3900, but now I'm having to deal with a small issue in the post-processing. I'm unable to properly obtain the wall shear stress, some ripples appear along the span, as shown in the screenshot. The C0 projection (FieldConvert module) has not worked and I'm not sure if it should have worked to the surface mesh obtained from the XML file. Does anyone know what I should do to fix this problem or have any other suggestions in this case? Thank you! Regards, Paulo Henrique PhD StudentInstituto Tecnologico de Aeronautica - ITA 12228-900 - Sao Jose dos Campos - SP - BRAZIL

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Set up Help
by Paul Liu 28 Apr '21

28 Apr '21

******************* 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, Some really stupid questions. I managed to install Nektar++ from the source. The installation was successful as I managed to run "ctest" under the "build" folder and all the tests are passed. Then I tried to add the path of the solvers that I want "AcousticSolver" and " to my ".bashrc" file so that I can call the function/exectuable. ex: export PATH = "home/paul/nektar++/build/solvers/ADRsolver:$PATH". However when I tried to call the function to run the tutorial on the advection-convection equation I was getting segmentation errors. My tutorial files are located outside of the "build" folder where all the code was built, is that the reason? If not what should I do/try to debug this problem. Sorry I am completely new to linux haha. *YiLin Liu * *403-397-3457* *liuyilin.liu(a)gmail.com <liuyilin.liu(a)gmail.com>* MASc Student at CML <https://cml.mech.ubc.ca/> UBC

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Nektar++ 5.0.2 Released.
by Chris Cantwell 22 Apr '21

22 Apr '21

Dear all, We are pleased to announce the release of Nektar++ v5.0.2. This release includes a number of further bug fixes to the 5.0.1 release: **Library** - Fix bug in StdHexExp FillMode (!1192) **Documentation** - Updated Documentation to include HDF5 Mesh Output (!1230) **CI** - Add Debian Bullseye to CI system (!1181) - Removed Ubuntu Trusty (14.04) from CI and added Focal (20.04) (!1238) **BuildSystem** - Updated third party zlib version to 1.2.9 to resolve OCE source build issue (!1227) - Adding SolverUtils as a core library that is built by default (!1240) As always, if you encounter any problems please feel free to contact us on the mailing list nektar-users(a)imperial.ac.uk. Cheers, 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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Compressible flow solver
by Octavio Morales 17 Apr '21

17 Apr '21

******************* 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've been trying to work with this solver in a high sub-sonic compressible regime (Ma=0.87), however this appears: ======================================================================= EquationType: NavierStokesCFE Session Name: Cilindro Spatial Dim.: 2 Max SEM Exp. Order: 3 Num. Processes: 3 Expansion Dim.: 2 Riemann Solver: HLLC Advection Type: Projection Type: Discontinuous Galerkin Diffusion Type: Advection: explicit AdvectionType: WeakDG Diffusion: explicit Time Step: 1e-05 No. of Steps: 60000 Checkpoints (steps): 400 Integration Type: ClassicalRungeKutta4 ======================================================================= Initial Conditions: - Field rho: rhoInf - Field rhou: rhoInf * uInf - Field rhov: rhoInf * vInf - Field E: pInf / (Gamma - 1) + 0.5 * rhoInf * (uInf * uInf + vInf * vInf) Writing: "Cilindro_0.chk" (0.00527309s, XML) 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: [[28957,1],1] Exit code: 1 -------------------------------------------------------------------------- ************************************************************************************************************************************************************************ This is the input: ************************************************************************************************************************************************************************ <EXPANSIONS> <E COMPOSITE="C[0]" NUMMODES="3" FIELDS="rho,rhou,rhov,E" TYPE="MODIFIED" /> </EXPANSIONS> <CONDITIONS>  <PARAMETERS> TimeStep = 0.00001 FinTime = 0.6 NumSteps = FinTime/TimeStep IO_CheckSteps = 400 IO_InfoSteps = 400 GasConstant = 287.058 Gamma = 1.4 pInf = 22600 rhoInf = 0.364 Mach = 0.87 cInf = sqrt(Gamma * pInf / rhoInf) uInf = Mach*cInf vInf = 0.0 Twall = 258.5 Re = 400000 mu = 0.00001167 Pr = 0.72 </PARAMETERS> <SOLVERINFO> </SOLVERINFO> ************************************************************************************************************************************************************************** Is the problem related to the quality of the mesh or it is related to the Solver info module? Any help is extremely appreciated. Thanks for your time. Morales González Octavio Augusto. U-MOFABI Facultad de Ingeniería, Universidad Nacional Autónoma de México.

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Post-processing - Wall Shear Stress
by paulohferr＠yahoo.com 17 Apr '21

17 Apr '21

******************* 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 ran a typical simulation of a circular cylinder at Re = 3900, but now I'm having to deal with a small issue in the post-processing. I'm unable to properly obtain the wall shear stress, some ripples appear along the span, as shown in the screenshot. The C0 projection (FieldConvert module) has not worked and I'm not sure if it should have worked to the surface mesh obtained from the XML file. Does anyone know what I should do to fix this problem or have any other suggestions in this case? Thank you! Regards, Paulo Henrique PhD StudentInstituto Tecnologico de Aeronautica - ITA 12228-900 - Sao Jose dos Campos - SP - BRAZIL

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