September 2021 - Nektar-users

variable coeffient in Helmholtz solver
by mohammadreza rouhanian 29 Sep '21

29 Sep '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. ******************* Dear all I want to solve a two-phase flow with Nektar++. The governing equations lead to div(viscosity(grad) - factor)u=RHS that should solve with Helmholtz solver in the velocity correction scheme. As the flow is two-phase the viscosity varied across the domain. To solve the above equation, I set eVarCoeff D00=D11=D22=viscosity, but it doesn't work. Would you say how can I set the above equation in helmsolve? best regards, Rouhanian

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FieldConvert
by Alessandro Alberto de Lima 21 Sep '21

21 Sep '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'm trying to convert a field to some specific points. I tried to use: mpirun -np 32 FieldConvert-rg -m interppoints:fromxml=1cylQ3D_msh2.xml:fromfld=1cylQ3D_msh2.fld:box=400,200,300,-1.0,3.0,-1.0,1.0,0.001,3.0 1cylQ3D_msh2_2059.dat and i get a "Segmentation fault" as result. Then I tried as a simple test: FieldConvert -m interppoints:fromxml=1cylQ3D_msh2.xml:fromfld=1cylQ3D_msh2.fld:topts=file.csv file2.dat The file.csv: # x, y, z 5.0,-2.0,1.0 7.5,2.0,1.0 8.0,5.0,1.0 And had the same "Segmentation fault" as result. Before all of that, i was converting my fields to paraview and then converting to csv files. I'm spanding to much time. There is a method to generate a csv field direct from nektar? Thank you for your support. Alessandro

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Acoustics of Laminar Flow Cylinder
by Paul Liu 21 Sep '21

21 Sep '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, I am a current masters student trying to work on some acoustics. I was wondering if anyone has any experience with trying to calculate the acoustic perturbation pressure of a simple stationary cylinder in laminar flow. Specifically, I am trying to use the -dp/dt (time derivative of pressure) from a DNS (direct numerical simulation) of the flow solution for the laminar flow of the cylinder (Re=200). This term seems quite large up to 200+ in magnitude which perplexes me. I am trying to insert -dp/dt as a source in the pressure/energy equation. If anyone has any tips or thoughts please let me know. Thank you all so much. *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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Elastodynamic solver
by Lozano Duarte, Daniel Hernando 01 Sep '21

01 Sep '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. ******************* Dear all, Receive a warm greeting from Berlin, I am a PhD student and currently, I am working in elastodynamic models for the study of guided waves propagation. My framework is a semi-analytical method called the Scaled Boundary Finite Element Method. However, I have been exploring other possibilities and ended up finding Nektar++. So as you might notice I am new with Nektar, but there is no solver for the equations of elastodynamics. I would like to know if some of you have some experience with this, I'd really appreciate your support. I thank you in advance! Looking forward to hearing from you soon! Regards, Daniel. Bundesanstalt für Materialforschung und -prüfung (BAM) Daniel Hernando Lozano Duarte 8.4 Division/Section (Acoustic and Electromagnetic Methods) Unter den Eichen 87 12205 Berlin GERMANY P: + 49 30 8104-4538 + 39 3382621636 Daniel-Hernando.Lozano-Duarte(a)bam.de<mailto:Daniel-Hernando.Lozano-Duarte@bam.de> www.bam.de<http://www.bam.de/> _______________________________________________________ Die BAM ist eine Bundesoberbehörde im Geschäftsbereich des Bundesministeriums für Wissenschaft und Energie.

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