July 2014 - Nektar-users - imperial.ac.uk

Different Element Types
by Kamil ÖZDEN 30 Jul '14

30 Jul '14

Dear All, Is there any way to generate a problem in Nektar++ with a mesh including different element types (quads+hexas+prisms etc.)? Regards, Kamil

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Different Element Types in a Mesh
by Kamil ÖZDEN 29 Jul '14

29 Jul '14

Dear Dr. Comerford, For Nektar to solve a problem, do I have to generate the mesh with a single type of element? Because, when I try to convert a mesh (which is the combination of different type of elements quads+hexas+prisms) like the one below to an .xml file via MeshConvert, I'm getting such a warning message: *"Different Types of Elements in Same Composite".* I have to define the whole body as a single volume to solve my problem. Is there any way to define different types of elements in a single composite? Regards, Kamil

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MeshConvert Problem
by Kamil ÖZDEN 24 Jul '14

24 Jul '14

Dear All, I generated the mesh below in Gmsh by generating three volumes and defining them as a single physical volume. Then I tried to convert it to .xml by using MeshConvert, it did but I got the following messages. After that by using this .xml file I tried to convert it to .vtu file in XmlToVtk executer. However, I got warning messages like below and the following mesh in Paraview . Moreover when I tried to open the .dat file by using XmlToTecplot, Tecplot says "Aspect ratio exceeds ratio limit. The ratio has been just adjusted." and "Axis Mode has been reset to be XYDependent" and got the following view. Do you know how can I solve this problem? I'm sending the .msh and .xml files in the attachment. Regards, Kamil

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Does Nektar++ support neighbor elements with non-matching faces
by Cuneyt Sert 22 Jul '14

22 Jul '14

Hi, Does Nektar++ support neighbor elements with non-matching faces? Such as one big face connected to multiple smaller faces with hanging node(s), which may be obtained after a mesh adaptation. Or a mesh with multiple structured regions with non-matching interfaces? Cuneyt

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Mesh Convert Problem
by Kamil ÖZDEN 18 Jul '14

18 Jul '14

Dear All, I'm trying to generate an .xml file from the .msh file attached which I got from Gmsh. But when I tried to do that such an error come to the screen: What may be the reason for this error? Regards, Kamil

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Gmsh and boundary conditions
by Kamil Ozden 07 Jul '14

07 Jul '14

Dear All, As far as I understand Gmsh only creates the geometry and the mesh. How can we define the boundary conditions, solver info's etc. to the Nektar's xml file? Do we manually write it into the .xml file or is there another way to do this? Regards, Kamil

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Nektar++ and Mesh Generators
by Kamil Ozden 02 Jul '14

02 Jul '14

Dear All, I'm a new Nektar++ user and I want to use it in my PhD thesis which is about stenosed arteries. I want to learn that is it possible to generate mesh with mesh generators other than Gmesh like ICEM CFD, Ansys Workbench Mesher with .msh extension to get .xml file of Nektar++? Regards, Kamil

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Questions About Turbulent Pipe Flow Quasi-3D Tutorial
by Kamil ÖZDEN 02 Jul '14

02 Jul '14

Dear All, I have some questions about Turbulent Pipe Flow Quasi-3D Tutorial: * When I run this tutorial with DELL Workstation with 12 core the analysis finished at 335000th time step but in the xml file it is written that NumSteps=2000000. Is this a random number or is there a way to calculate this number of time steps? * In this problem Quasi-3D approach is used but there is no information about the length of the pipe. At first I thought this is a periodic problem but there is also no periodic boundary condition in the xml file. Can you please clarify this point? o Moreover, when I converted the last *.chk file to Tecplot's dat file I only see the front face of the pipe (2D) how can I add the third dimension to see the contours in 3D as shown in the link below: + http://www.nektar.info/wiki/3.4/UserGuide/Examples/IncNavierStokesSolver/Tu… o Is it possible to use Quasi-3D approach for all axisymmetric geometries like constricted 3D pipe as below: * In the Geometry it is said that D=1. Is it unitless otherwise what is its unit mm or meters? And finally regardless of the tutorial I want to ask that: * Is it possible in Nektar++ to use the solution of a mesh as an initial condition of another mesh? Regards, Kamil

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Nektar++ and Two-way flow simulations
by Kamil ÖZDEN 01 Jul '14

01 Jul '14

Dear All, Is it possible to held a two-way flow simulation (to describe both inlet and outlet in a simple boundary) with Nektar++? Regards, Kamil

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