- Nektar-users - imperial.ac.uk

direct solver adjoint advection?
by A.P. 01 Aug '21

01 Aug '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. ******************* Hello, does the direct solver support adjoint advection: <I PROPERTY="SolverType" VALUE="CoupledLinearisedNS" /> <I PROPERTY="EQTYPE" VALUE="SteadyLinearisedNS" /> <I PROPERTY="EvolutionOperator" VALUE="Adjoint" /> Alex Proskurin Altai state technical university

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Question about the flow stability computation of a moving body
by 朝黎明 22 Jul '21

22 Jul '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, Sorry for my interruption. I want to use Netkar++ to investigate the flow stability around a flapping plate. However, I found there are no tutorials about the moving body. Would someone kindly give me some suggestions or share your tutorials about the moving body? With best wishes! Li-Ming

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Fieldconvert question
by Vidhi Zala 19 Jul '21

19 Jul '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 am wondering if there is a way to specify the number of points and basis type while converting chk -> vtu? I notice that irrespective of the quadrature points specified in the session file, the resulting vtu always has nummodes points. Any advice would be appreciated. Thanks V -- ,-~~-.___._. / | ' \ | |--------. Vidhi Zala ( ) 0 | | | School of Computing \_/-, ,----' | | | Scientific Computing and Imaging Institute ==== !_!-v---v--. University of Utah / \-'~; .--------. / __/~| ._-""|| | vidhi.zala(a)utah.edu =( _____|_|____||________| http://sci.utah.edu/people/vidhi.html I support Ruff Haven Crises Shelter for Homeless Pets <https://www.ruffhaven.org/donate>. Consider a donation today :)

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Transient Growth Analysis
by gongminjiang＠hrbeu.edu.cn 16 Jul '21

16 Jul '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 Sir or Madam, I have two questions when using transient analysis: 1. The transient growth analysis in Nektar++ is only useful for steady or periodic base flow, right? 2. The CFL when processing the backward equation maybe much large. Is it OK for linearised operator? Regards Gong

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Can Nektar++ filter architecture work for my filter application?
by Vidhi Zala 15 Jul '21

15 Jul '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 am implementing an algorithm that takes an intermediate solution [image: {U}_n] at time n and transforms it to [image: \tilde{U}_n]. Inside SolverUtils/UnsteadySystem.cpp, I want to feed this transformed value back to the TimeIntegrate() call at the beginning of the time loop, so [image: {U}_{(n+1)}] will be formed using [image: \tilde{U}_n]. I wrote a Nektar++ filter that takes the m_fields object and modifies its phys and coeffs attributes using my filter's update() method. Upon return, I verify that m_fields indeed have [image: \tilde{U}] , which are different from the [image: U]. But the change is not passed to the next integration timestep. I tried to update the local variable "fields" used to initialize the integration scheme from [image: {U}_n] to [image: \tilde{U}_n]. The integration object is still unaware of the change to the intermediate solution. I suspect that the time integration object does not expose a *setter *method for the solution vector objects. I checked all the existing Nektar++ filters, but from my understanding, none of those change the values of the intermediate solutions. The only way I could get my filter to work is by calling the initializer of the time integration scheme at every timestep with the modified "fields" object. While it works for my experiments, I need advice about where architecture-wise, should I put my *filter *such that I don't need to modify UnsteadySystem.cpp at all. Thanks much! V -- ,-~~-.___._. / | ' \ | |--------. Vidhi Zala ( ) 0 | | | School of Computing \_/-, ,----' | | | Scientific Computing and Imaging Institute ==== !_!-v---v--. University of Utah / \-'~; .--------. / __/~| ._-""|| | vidhi.zala(a)utah.edu =( _____|_|____||________| http://sci.utah.edu/people/vidhi.html

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Regarding online Nektar++ workshop
by Abhishek Kumar 12 Jul '21

12 Jul '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. ******************* Hello all, I hope everyone is doing well. I wanted to suggest about Nektar++ workshop. Unfortunately, due to COVID, this workshop was postponed. Still, it looks that it will be hard to organise a regular workshop. Will it be possible to organise an online Nektar++ workshop this year. With regards Abhishek -- --------------------------------------------------------------------------------------- Abhishek Kumar Assistant Professor (Research) Centre for Fluid and Complex Systems Coventry University, Coventry CV15FB The United Kingdom Phone: +44 24 7765 9150 Mobile: +44 7464026494 ---------------------------------------------------------------------------------------

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3D mesh with all element types and periodic boundaries
by Vidhi Zala 10 Jul '21

10 Jul '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 all, For the 3D experiment, how important it is to do periodic bcs? Is time-dependent dirichlet okay? I have perfect composite mesh in 3D but still struggling with periodic bcs. V -- ,-~~-.___._. / | ' \ | |--------. Vidhi Zala ( ) 0 | | | School of Computing \_/-, ,----' | | | Scientific Computing and Imaging Institute ==== !_!-v---v--. University of Utah / \-'~; .--------. / __/~| ._-""|| | vidhi.zala(a)utah.edu =( _____|_|____||________| http://sci.utah.edu/people/vidhi.html

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why is PhysDeriv not a linear function
by Martin Wilfried Hess 24 Jun '21

24 Jun '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. ******************* Hello, I am calling PhysDeriv from an Expansion Class Object. Why is this not linear? In the sense that if I call PhysDeriv for any linear combination of vectors it should be the same as computing the linear combination of the PhysDeriv of the vectors. Martin Hess -- -- Martin Hess, Ph.D., Post-doctoral research fellow SISSA mathLab, International School for Advanced Studies Office A-434 (4th floor), via Bonomea 265, I-34136 Trieste, Italy phone: +39 040 3787 491 email: mhess(a)sissa.it

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Fix for addfld module
by Abhishek Kumar 21 Jun '21

21 Jun '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 detected a bug with addfld module of FieldConvert in master branch. This error is coming as the expansion is not initialised. It works if we add m_f->SetUpExp(vm); at the beginning of "ProcessAddFld::Process(po::variables_map &vm) " function, and also remove "boost::ignore_unused(vm);". I hope this can be corrected in the master branch. With regards Abhishek -- --------------------------------------------------------------------------------------- Abhishek Kumar Assistant Professor (Research) Centre for Fluid and Complex Systems Coventry University, Coventry CV15FB The United Kingdom ---------------------------------------------------------------------------------------

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Aerodynamic forces
by Alessandro Alberto de Lima 18 Jun '21

18 Jun '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 Guys, I would like to know how the aerodynamic forces are calculated in nektar, the dimensions of the values on the .fce output file and its relation with the aerodynamic coefficients. Thank you. Alessandro

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