August 2020 - Nektar-users

Absorption Forcing Function for Physiological Flow
by DEBSHANKAR GHOSH 25 Aug '20

25 Aug '20

******************* 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, In this presentation slides obtained from Nektar++ workshop 2015 (attached below), I see that an absorption forcing function is applied to account for the negative part of the physiological waveform (Slide 6 of 13). Can someone provide any insight into how the various parameters involved in the forcing function are calculated? Also, if there are any available session files using the forcing function, would it be possible to provide me these files? Regards, *Debshankar Ghosh* 2016A1TS0559P Mobile- +91-9874097561 Email: Personal <ghoshdeb97(a)gmail.com> || University <f2016559(a)pilani.bits-pilani.ac.in> ▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄▄ Birla Institute of Technology and Science, Pilani Vidya Vihar, Pilani Rajasthan - 333031, India

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error: "A parallel solver must be used when run in parallel"
by Professor Ding、 23 Aug '20

23 Aug '20

******************* 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 friends: I have select "use MPI" during the cmake process. but when i run incompressbile flow solver, it still gives me the error of "A parallel solver must be used when run in parallel". How to resolve this problem. Regards | | Professor Ding、 | | ztdepyahoo(a)163.com | 签名由网易邮箱大师定制

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Re: [Nektar-users] Problem in CWIPI
by Laughton, Edward 22 Aug '20

22 Aug '20

Hi Mahdi, Thanks for spotting this! It looks like something I broke while rewriting the DG MPI implementation. I’ve had a quick go at fixing it, please check if this works for you by trying the branch “fix/FixCWIPIVirtualFunctionSpecifiers” on GitLab. I haven’t tested it but I think this all that is required – if that doesn’t work then please let me know what the next error is! Alternatively try the v5.0.0 release which shouldn’t have this issue. Cheers, Ed From: <nektar-users-bounces(a)imperial.ac.uk> on behalf of Mahdi Erfanian Nakhchi <mahdi.nakhchi(a)northumbria.ac.uk> Date: Saturday, 22 August 2020 at 08:36 To: "nektar-users(a)imperial.ac.uk" <nektar-users(a)imperial.ac.uk> Subject: [Nektar-users] Problem in CWIPI CAUTION: This email originated from outside of the organisation. Do not click links or open attachments unless you recognise the sender and know the content is safe. This email from mahdi.nakhchi(a)northumbria.ac.uk 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://eur03.safelinks.protection.outlook.com/?url=https%3A%2F%2Fspam.ic.a…> to disable email stamping for this address. Dear NEKTAR users, I have successfully installed NEKTAR without CWIPI on our local HPC cluster and it works fine. Now, I want to build a new NEKTAR by including the CWIPI function. But, the installation is not successful. I am using Openmpi. I would be grateful if you have any idea how to resolve this issue. Many thanks. Best regards, Mahdi Postdoc Researcher Northumbria University [cid:image001.png@01D6787E.338624D0] This message is intended solely for the addressee and may contain confidential and/or legally privileged information. Any use, disclosure or reproduction without the sender’s explicit consent is unauthorised and may be unlawful. If you have received this message in error, please notify Northumbria University immediately and permanently delete it. Any views or opinions expressed in this message are solely those of the author and do not necessarily represent those of the University. Northumbria University email is provided by Microsoft Office365 and is hosted within the EEA, although some information may be replicated globally for backup purposes. The University cannot guarantee that this message or any attachment is virus free or has not been intercepted and/or amended.

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Problem in CWIPI
by Mahdi Erfanian Nakhchi 21 Aug '20

21 Aug '20

******************* 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, I have successfully installed NEKTAR without CWIPI on our local HPC cluster and it works fine. Now, I want to build a new NEKTAR by including the CWIPI function. But, the installation is not successful. I am using Openmpi. I would be grateful if you have any idea how to resolve this issue. Many thanks. Best regards, Mahdi Postdoc Researcher Northumbria University [cid:c8346266-de78-44c0-a439-7c5dc132130e] This message is intended solely for the addressee and may contain confidential and/or legally privileged information. Any use, disclosure or reproduction without the sender's explicit consent is unauthorised and may be unlawful. If you have received this message in error, please notify Northumbria University immediately and permanently delete it. Any views or opinions expressed in this message are solely those of the author and do not necessarily represent those of the University. Northumbria University email is provided by Microsoft Office365 and is hosted within the EEA, although some information may be replicated globally for backup purposes. The University cannot guarantee that this message or any attachment is virus free or has not been intercepted and/or amended.

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Simulation of convection in Nektar++.
by Edward Threlfall 21 Aug '20

21 Aug '20

******************* 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 users, I am trying to set up a simulation of Rayleigh-Benard convection in Nektar++. I have seen a poster by Hossein and Sherwin from last year's workshop which seems to do a similar sort of thing, but, based on my (limited) understanding of the framework, I am not sure how this was done or how to set up something similar myself (e.g. the system is coupled incompressible (?) Navier-Stokes and advection-diffusion; so, was it the case that the two solvers were run with coupling between them?). I note there is a separate thread running on convection at the moment; I could have emailed the poster's author directly, but perhaps a public discussion of how to set up this type of problem will benefit others too. Many thanks, Dr. Ed Threlfall (UKAEA).

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Does nektar support the computation of natural convection problem with Bouseness assumption.
by Professor Ding、 18 Aug '20

18 Aug '20

******************* 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. ******************* | | Professor Ding、 | | ztdepyahoo(a)163.com | 签名由网易邮箱大师定制

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Regarding BodyForce in Nektar 5
by Abhishek Kumar 15 Aug '20

15 Aug '20

******************* 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 Dave, I found one issue with Nektar 5 regarding the BodyForce. In Nektar 4.5, you included "EVARS" for a running problem like Rayleigh Benard Convection. Now, with Nektar 5, when I use EVARS, it gives sigmetation fault. Could you please check? I have attached the session file, which work perfectly with Nektar 4.5. 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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time-dependent model reduction
by Martin Wilfried Hess 14 Aug '20

14 Aug '20

******************* 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 would like to implement a time-dependent model reduction. To do that, I want to mirror some of the class structure in the reduced order setting. I would like to start with the UnsteadySystem class, since there the time-stepping takes place. Now I am not so familiar with this factory pattern scheme. What would I need to do to have a, say UnsteadySystem_ReducedOrder class, which (for a start) does the same as the UnsteadySystem class and can be called with a different EQTYPE identifier in the session file? I want to use it for UnsteadyNavierStokes, the incompressible case. Thanks for any help, 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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Restarting a simulation from last data
by Silvia Ceccacci (HDR) 13 Aug '20

13 Aug '20

******************* 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 understand Nektar has a restart capability which involves renaming the last .fld output file as a .rst file. Then, configure the FUNCTION 'InitialConditions' accordingly. In case of large files, the .fld file is partitioned in files with names P0000000.fld, P0000001.fld, etc and the Info.xml file is generated. How do we generate the start file from the parallel partition? I assume a single .fld file is needed for restarting a simulation. Thank you for your help. Kind regards, Silvia

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Isothermal wall boundary In CompressibleFlowSolver
by Wang, Zhicheng 13 Aug '20

13 Aug '20

******************* 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, I'm using the CompressibleFlowSolver to simulate nitrogen flow in a square cavity, where there are two isothermal walls with different temperatures, and the rest of the walls are adiabatic. After looking into the manual for quite a while, my understanding is that the wall temperature is uniquely defined by parameter "Twall", there is no straightforward way to set up a different wall temperature in the parameter file. Has anyone run into the same issue before ? Can you give a hint how to implement this? Best regards Zhicheng Wang

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