September 2015 - Nektar-users

Figuring out biglobal floquet stability analysis of flow over cylinder
by Arfan Uddin 25 Sep '15

25 Sep '15

Hi all, I am trying to do Biglobal floquet stability analysis of flow over a cylinder. My base flow has converged and I am getting the Strouhal numbers correctly for different Reynolds numbers. Then I tried to do the stability analysis, but I am not getting the desired results for floquet multipliers. I think there are some wrong settings in my input file that I am not able to figure out. Can anyone look at my input files and help me figuring out the possible source of error? Please check the attached files. Here are the steps I am following:1. Solve for the 2D base flow using UnsteadyNavierStokes equations. (Input file Cylinder.xml)2. Get the base flow (.bse files) by taking 32 time slices over one period. (Input file Cylinder-base.xml)3. Use the base flow to set up stability simulation for a specified LZ (Input fie Cylinder-Stability.xml) The output .evl file is also attached. General data: Re=220, LZ=2.4166, Expected floquet multiplier=0.45. I am new to the solver. Any help will be greatly appreciated. Regards,Arfan Uddin

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ctest fails when compiling nektar++-4.2.0
by Sharma, Manish (sharmamh) 25 Sep '15

25 Sep '15

Hello All, I am trying to compile the nektar++-4.2.0 on a Linux machine. When I run the ctest at the end, all the tests fail. I have also tried to use the info from the FAQ's in the userguide4.2.0, but it didn't help. Any help to resolve this issue will be greatly appreciated. Thank you, Manish Sharma

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High order boundary representation of cylinder
by Jian Yu 25 Sep '15

25 Sep '15

Dear all, I have generated a mesh of the gmesh format around a 3D cylinder(radius=0.5). When I perform the following command: ./MeshConvert -m cyl:surf=16,17:r=0.5:N=10 cylinder_straightlines.xml cylinder_highorder.xml The following error message is generated: Fatal : Level 0 assertion violation This function is only valid for shape type geometries terminate called after throwing an instance of 'ErrorUtil::NekError' what(): Level 0 assertion violation This function is only valid for shape type geometries Can anybody tell me how to solve this problem? The msh and cylinder_straightlines.xml files are attached. Thank you! Best Jian Yu

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Re: [Nektar-users] Filter History Point output error
by Sherwin, Spencer J 24 Sep '15

24 Sep '15

Hi Douglas, Thanks for confirming. Chengwang you could try writing out all the data a the history point you are considering on every plane. This information would then be sufficient to do a backwards transform and get the point anywhere along the span you wish. Actually it might be worth us putting in an option to do this from the filter since this is what will be required anyway even if we search for the physical point. Cheers, Spencer. On 24 Sep 2015, at 17:55, Serson, Douglas <d.serson14(a)imperial.ac.uk<mailto:d.serson14@imperial.ac.uk>> wrote: Hi Spencer, I don't use this filter, but this seems to be the case. I think this is intentional, since the output file in the 3DH1D case contains the information "(in Wavespace)". Cheers, Douglas ________________________________________ From: Sherwin, Spencer J Sent: 24 September 2015 17:17 To: Chengwang Xiong Cc: nektar-users; Serson, Douglas Subject: Re: [Nektar-users] Filter History Point output error Hi I wonder if it might be outputting the Fourier coefficient on the plane rather than the physical value. Douglas is this something you can help Chengwang with? Thanks Spencer Sent from my iPhone On 24 Sep 2015, at 17:15, Chengwang Xiong <21358955(a)student.uwa.edu.au<mailto:21358955@student.uwa.edu.au><mailto:21358955@student.uwa.edu.au>> wrote: Hi All, I want to output the history points of a 3D1H simulation using the parameter OutputPlane . But I found only the result at z=-1 (OutputPlane=0) is correct, while the values at other points are much smaller than what they should be. I have already updated to version 4.2.0. Has anyone encoutered the same problem? Thank you for any suggestion! ________________________________ Best regards, Chengwang Xiong From: David Moxey<mailto:d.moxey@imperial.ac.uk> Date: 2015-09-24 18:19 To: Sharma, Manish (sharmamh)<mailto:sharmamh@mail.uc.edu> CC: nektar-users(a)imperial.ac.uk<mailto:nektar-users@imperial.ac.uk><mailto:nektar-users@imperial.ac.uk> Subject: Re: [Nektar-users] ctest fails when compiling nektar++-4.2.0 Hi Manish, We'll need a few more details in order to assist you. Can you run ctest --output-on-failure and forward a sample of the error messages you're getting? Thanks, Dave On 23 Sep 2015, at 19:05, Sharma, Manish (sharmamh) <sharmamh(a)mail.uc.edu<mailto:sharmamh@mail.uc.edu><mailto:sharmamh@mail.uc.edu>> wrote: Hello All, I am trying to compile the nektar++-4.2.0 on a Linux machine. When I run the ctest at the end, all the tests fail. I have also tried to use the info from the FAQ’s in the userguide4.2.0, but it didn’t help. Any help to resolve this issue will be greatly appreciated. Thank you, Manish Sharma _______________________________________________ Nektar-users mailing list Nektar-users(a)imperial.ac.uk<mailto:Nektar-users@imperial.ac.uk><mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users -- David Moxey (Research Associate) d.moxey(a)imperial.ac.uk<mailto:d.moxey@imperial.ac.uk><mailto:d.moxey@imperial.ac.uk> | www.imperial.ac.uk/people/d.moxey<http://www.imperial.ac.uk/people/d.moxey><http://www.imperial.ac.uk/people/d.moxey> Room 363, Department of Aeronautics, Imperial College London, London, SW7 2AZ, UK. _______________________________________________ Nektar-users mailing list Nektar-users(a)imperial.ac.uk<mailto:Nektar-users@imperial.ac.uk><mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users _______________________________________________ Nektar-users mailing list Nektar-users(a)imperial.ac.uk<mailto:Nektar-users@imperial.ac.uk> https://mailman.ic.ac.uk/mailman/listinfo/nektar-users Spencer Sherwin McLaren Racing/Royal Academy of Engineering Research Chair, Professor of Computational Fluid Mechanics, Department of Aeronautics, Imperial College London South Kensington Campus London SW7 2AZ s.sherwin(a)imperial.ac.uk<mailto:s.sherwin@imperial.ac.uk> +44 (0) 20 759 45052

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(no subject)
by Soumya Dutta 20 Sep '15

20 Sep '15

Hi All, I have successfully installed the library is able to run some solvers and generate .fld data. However in order to visualize I want them to be converted to vtk format but I can not find the *fldtovtk* executable file. I compiled nektar 4.2 in ubuntu 12.04 with vtk and qt support. Am I missing something? Any help would be greatly appreciated. -- *mindbender*

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Heat transfer
by Stanisław Gepner 13 Sep '15

13 Sep '15

Dear all, Is it possible to solve a heat transfer problem using Nektar? I found this: http://wwwf.imperial.ac.uk/ssherw/spectralhp/nektar/demonstrations/isoconto… Best regards, Stan Gepner

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