November 2020 - Nektar-users

Outflow BC for buoyant flows
by Sartaj Tanweer 13 Dec '20

13 Dec '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 am using Nektar++(4.4.1) for computations of the flow past a square cylinder placed near a moving wall under the influence of buoyancy. I have used *"HOutflow*" boundary condition at the outlet as suggested by the user guide, but I got the wrong result. Could someone please suggest a right BC at the outlet? I have attached the mesh and condition files and the resultant streamlines. with best regards, Sartaj Tanweer

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Help MESHGEN
by Octavio Morales 13 Dec '20

13 Dec '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 again, I am trying to use the Mesh Generation option by setting the NEKTAR_USE_MESHGEN option to ON but when I try to compile it this pops up

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Boundary layer splitting
by Vishal Saini 13 Dec '20

13 Dec '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 all, Quick question: The user guide (v5.0) states: " To split a prism boundary layer on surface 11 into 3 layers with a growth rate of 2 and 7 integration points per element use the following: NekMesh -m bl:surf=11:layers=3:r=2:nq=7 MeshOnePrismLayer.xml Mesh3PrismsLayers.xml " What would be the correct nq when using, say, <E COMPOSITE="C[1]" NUMMODES="5" FIELDS="u,v,w" TYPE="MODIFIED" /> <E COMPOSITE="C[1]" NUMMODES="4" FIELDS="p" TYPE="MODIFIEDQUADPLUS1" />? I am confused because (a) different poly order in *u* and p and (b) I am using dealiasing and not sure if the "integration points" above would include the extra integration points or not. Thank you for your time. --- *Vishal SAINI*

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Error in installation: version `GLIBCXX_3.4.26' not found (required by /lib/x86_64-linux-gnu/libapt-pkg.so.6.0)
by Hamed Faghanpourganji 01 Dec '20

01 Dec '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 tried to install Nektar++ on Ubuntu, but I got the noted error in subject of this Emial. I already google it, but following links didn't help https://unix.stackexchange.com/questions/456918/how-do-i-install-glibcxx https://github.com/ufo-project/ufochain/issues/3 https://askubuntu.com/questions/1166292/version-glibcxx-3-4-26-not-found-ev… Anyone can help me with the installation? Thank you very much in advance. Kind regards, Hamed <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> Virusvrij. www.avast.com <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campai…> <#DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2>

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Regarding parallelisation of Nektar++
by Abhishek Kumar 24 Nov '20

24 Nov '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 am trying to understand the parallelisation of Nektar++. I have a question on the use of Row and Column communicator. Is both the communicators are used in the 2D mesh? Can I also get some reference of Nektar++ parallelisation strategy? 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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discontinuous results when using ariable polynomial order
by 王昭予 09 Nov '20

09 Nov '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 Prof. Sherwin Thanks for your reply. There is a problem is when I use variable polynomial order in the field, the results near the boundary between 2 domains with different polynomial order cant be smoothed by C0projection module. So how can I handle the discontinuous results in this case? Many thanks, Zhaoyu Wang Shanghai Jiao Tong University

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Nektar compile error - development version.
by Debbahi Saad 03 Nov '20

03 Nov '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, After a lot of trial and error, this is what I end up with trying to compile the fresh development version of Nektar. Here I reproducing the compile error since I encountered the same error on an hpc cluster rhel6 and Gcc-8.2.0, same thing on my workstation Gcc-8.2.0 running Centos 6.10 64bits. nevertheless, release version 5.0 does compile fine. I've been trying to compile the development version with nektar-error-on-warnings set OFF, with full build for all thirdparty packages, I also had the same error using cxxflags=-std=c++11 trying to limit the compiler features to c++11. Would you please check out the compile error output attached hereafter. Thanks to all of you. Saâd [22%] Building CXX object library/LibUtilities/CMakeFile s/LibUtilities.dir/LinearAlgebra/blas.cpp.o [ 22%] Building CXX object library/LibUtilities/CMakeFile s/LibUtilities.dir/LinearAlgebra/BlockMatrix.cpp.o In file included from /softroot/nektar++/library/Lib Utilities/Communication/CommCwipi.cpp:37: /softroot/nektar++/library/LibUtilities/Communication/CommCwipi.h:73:18: error: virtual function ‘virtual void Nektar::LibUtilities::CommCwipi::v_Finalise()’ overriding final function virtual void v_Finalise(); ^~~~~~~~~~ In file included from /softroot/nektar++/library/Lib Utilities/Communication/CommCwipi.h:41, from /softroot/nektar++/library/Lib Utilities/Communication/CommCwipi.cpp:37: /softroot/nektar++/library/LibUtilities/Communication/CommMpi.h:114:18: note: overridden function is ‘virtual void Nektar::LibUtilities::CommMpi: :v_Finalise()’ virtual void v_Finalise() final; ^~~~~~~~~~ /softroot/nektar++/library/LibUtilities/Communication/CommCwipi.cpp: In constructor ‘Nektar::LibUtilities::CommCwipi::CommCwipi(int, char**)’: /softroot/nektar++/library/LibUtilities/Communication/CommCwipi.cpp:52:55: error: no matching function for call to ‘Nektar::LibUtilities::CommMpi ::CommMpi()’ CommCwipi::CommCwipi(int narg, char *arg[]) : CommMpi() ^ In file included from /softroot/nektar++/library/Lib Utilities/Communication/CommCwipi.h:41, from /softroot/nektar++/library/Lib Utilities/Communication/CommCwipi.cpp:37: /softroot/nektar++/library/LibUtilities/Communication/CommMpi.h:112:14: note: candidate: ‘Nektar::LibUtilities::CommMpi::CommMpi(MPI_Comm)’ explicit CommMpi(MPI_Comm pComm); ^~~~~~~ /softroot/nektar++/library/LibUtilities/Communication/CommMpi.h:112:14: note: candidate expects 1 argument, 0 provided /softroot/nektar++/library/LibUtilities/Communication/CommMpi.h:103:26: note: candidate: ‘Nektar::LibUtilities::CommMpi::CommMpi(int, char**)’ LIB_UTILITIES_EXPORT CommMpi(int narg, char *arg[]); ^~~~~~~ /softroot/nektar++/library/LibUtilities/Communication/CommMpi.h:103:26: note: candidate expects 2 arguments, 0 provided /softroot/nektar++/library/LibUtilities/Communication/CommMpi.h:91:7: note: candidate: ‘Nektar::LibUtilities::CommMpi::CommMpi(const Nektar::LibUtilities::CommMpi&)’ class CommMpi : public Comm ^~~~~~~ /softroot/nektar++/library/LibUtilities/Communication/CommMpi.h:91:7: note: candidate expects 1 argument, 0 provided [ 23%] Building CXX object library/LibUtilities/CMakeFile s/LibUtilities.dir/LinearAlgebra/MatrixBase.cpp.o make[2]: *** [library/LibUtilities/CMakeFiles/LibUtilities.dir/Communication/CommCwipi.cpp.o] Error 1 make[2]: *** Waiting for unfinished jobs.... make[1]: *** [library/LibUtilities/CMakeFiles/LibUtilities.dir/all] Error 2 make: *** [all] Error 2

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