can any one suggest proper meshing for the geometry below. its a 3D non axisymmetric nozzle .

Answers

  • saagar268saagar268 Posts: 6Member

    i tried with 25 inflation layers from the closed surfaces and total of 0.7 million nodes .But then while running this in fluent there is reversed flow and the calculation stops. Please suggest a proper procedure for meshing .The research paper states that grid independence is reached at 0.8 mil nodes.

  • RobRob UKPosts: 11,730Forum Coordinator

    Open meshing tool, set global and local controls & mesh.

    The question you should be working on is what is the flow doing as it leaves the nozzle and will that impact on the flow in the nozzle.

  • saagar268saagar268 Posts: 6Member

    Thanks for answering Rob, i did it in meshing from fluent stack but wasn't getting the quality i need .So my question is that while giving inflation layer i generated it from all surfaces except for inlet and outlet but the paper shows only three surfaces were taken to generate from the inlet plane,the top and bottom profile faces. I am confused here.


  • saagar268saagar268 Posts: 6Member

    well the nozzle is one in a nozzle ring that is around the Turbine in a Turbo expander. There will be pressure decrease in nozzle and furthermore decrease in the turbo expander to liquefy the gas(He and N).

    Its a pressure based problem with 16 bar pressure and 50 K temperature at inlet, transient state.I am using a LES model while the reference paper is done in RANS model .

    if i am missing something please do tell.

  • RobRob UKPosts: 11,730Forum Coordinator

    Look at how the flow will behave in the nozzle and then into wherever the nozzle vents. Can you really define an outlet boundary pressure condition where you've set it? Don't inflate from the inlet and outlet as you'll be pushing flow across a cell with high aspect ratio, that'll not help with accuracy or stability.

  • saagar268saagar268 Posts: 6Member

    inlet pressure 16/8/16bar and outlet 12 /4.5/ 8 bar respectively .The mesh using adaptive control has bad quality


  • RobRob UKPosts: 11,730Forum Coordinator

    The above isn't much help, other than to tell me the mesh is awful. Have a look to see where the bad cells are and try to understand why.

  • saagar268saagar268 Posts: 6Member

    mr Rob what info do you need please specify, I am looking into the mesh issues .

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