Interphase CFX-Pre - not exporting all nodes at interphase

niels_normannniels_normann Member Posts: 2

Hallo. I am trying to simulate a heatexchanger in Ansys CFX where there exists 2 interphases. 1 with cold water-solid pipe and 2 solid pipe- fluegas (hot). I made 3 structered mesh in ICEM, 1 for the water domain, 1 for the solid and 1 for the fluegas. As seen in the picture below relatively many nodes are generated at the interphase for the flue structured mesh.


However, as seen in the next picture in CFX-pre only 6 nodes are generated at the flue-gas interphase (green arrow).

Why are all the nodes not exported from ICEM to CFX? ( all the nodes are exported correctly from the other domains).

Best Answer

  • DrAmineDrAmine GermanyPosts: 6,847Forum Coordinator
    Accepted Answer

    You created the mesh: does the mesh look as you expect? If you select one boundary and just hit Mesh Statistics in CFX: you will get more information regarding the mesh on that surface.

Answers

  • DrAmineDrAmine GermanyPosts: 6,847Forum Coordinator

    Show the mesh in CFX and check that again. Do not rely on boundary marks to qualify that!

  • niels_normannniels_normann Posts: 6Member

    Thanks for the quick answer!

    So this is the mesh for the flue-gas - so CFX pre does import the nodes? There just something wrong with the boundary marks?

    mesh for the wall(solid)

    mesh for water domain


  • niels_normannniels_normann Posts: 6Member

    Thanks that works i does import all the nodes, it just does not show by the interphase indicator. However, i thought that was the reason for the high temperature in the liquid water. it appears that the solver has a hard time for the volume fractions to converge, eventhough that the liquid water never meets the flue gas, so the composition should be constant. I tried the beta version where i just define the water domain and flue gas domain but that did not work (wrong temperatuer) i have also tried the homogenous model with free surface, where defined constant compostion for the flue and water. But that also does not seem right as there is no interphase as they never meet... So how to define liquid water and flue gas that never meets?

  • DrAmineDrAmine GermanyPosts: 6,847Forum Coordinator

    Create a new thread with your new question and introduce the problem.

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