August 2016 - Nektar-users

what is the boundary condition for the first and second intermediate velocity field?
by 丁老师 19 Aug '16

19 Aug '16

Dear Nektar group: Could you please give me some suggestions about the boundary condition for the first and second intermediate velocity field? Does it use the same with the real velocity boundary conditions. Regards Your Sincerely Ding

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Team chat
by David Moxey 19 Aug '16

19 Aug '16

Hi all, One of the outcomes of our user group meeting way back in June was to trial the use of a chat-based system for developers to ask questions and collaborate on a bit more of an informal basis. The easiest option turned out to be Slack, at least for trialling this amongst our group. For those unfamiliar with Slack, you can see some of the functionality here: https://slack.com/is -- it's essentially a chat room, with apps for desktop and phone, searchable history and somewhere to put attachments. The Nektar++ signup page is here: https://nektarpp.slack.com/signup Right now you need an Imperial or Utah email address to sign up, so if you don't have this and would like an invite, just reply to this email and I will send one your way. I'd encourage as many of you to take part as possible since if this is going to be successful then it requires a critical mass of people to participate! Cheers, Dave -- David Moxey (Research and Teaching Fellow) d.moxey(a)imperial.ac.uk | www.imperial.ac.uk/people/d.moxey Room 364, Department of Aeronautics, Imperial College London, London, SW7 2AZ, UK.

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A milestone
by David Moxey 15 Aug '16

15 Aug '16

Hi all, Just another quick (and happy!) note -- I noticed that we've now passed 10,000 commits and 600 merge requests for Nektar++, which is (in my mind at least) a big milestone for us! I just wanted to say thanks to everyone that has contributed code, bug reports and their time to making this such a successful project. Cheers, Dave -- David Moxey (Research and Teaching Fellow) d.moxey(a)imperial.ac.uk | www.imperial.ac.uk/people/d.moxey Room 364, Department of Aeronautics, Imperial College London, London, SW7 2AZ, UK.

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HDF5 support
by David Moxey 15 Aug '16

15 Aug '16

Dear all, The latest master now contains a new parallel output format that is based on the HDF5 dataset format. It's hoped we can make our I/O more efficient at very large core counts as a consequence. The default format is still our directory-based structure. I'd appreciate it if you can test this out on your simulations and let me know (a) the speed difference in reading/writing and (b) any bugs you encounter. - To enable HDF5, configure CMake with the NEKTAR_USE_HDF5 setting, which also requires NEKTAR_USE_MPI. Note that most clusters have HDF5 modules available that are usually detected by the CMake configuration (e.g. on ARCHER: module load cray-hdf5-parallel) - To run a simulation using the new format: IncNavierStokesSolver --io-format Hdf5 session.xml or put <I PROPERTY="IOFormat" VALUE="Hdf5" /> into your <SOLVERINFO> section. - To convert from XML based format (either serial or parallel) to HDF5: FieldConvert in.fld out.fld:fld:format=Hdf5 Note you don't need the session file for this. - Or the other way around: FieldConvert in.fld out.fld:fld:format=Xml Thanks also to Rupert Nash and Michael Bareford at EPCC for helping get this done as part of our eCSE funding. Cheers, Dave -- David Moxey (Research and Teaching Fellow) d.moxey(a)imperial.ac.uk | www.imperial.ac.uk/people/d.moxey Room 364, Department of Aeronautics, Imperial College London, London, SW7 2AZ, UK.

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