Acusolve CHT Result Export

Akhilesh Katipally
Akhilesh Katipally New Altair Community Member
edited October 2020 in Community Q&A

Hello, I am running a Laminar CHT analysis (Pipe flow). How do I select the outputs? Acusolve is not exporting the surface film coefficient (HTC) at the interface between the solid and the fluid domains. It outputs the temperature, pressure and velocities.

 

On a side note, I am using HM 2017.2 and how to do set up a CHT analysis in HM? Specifically, I wanted to know how to setup the interface. Looking at the tutorials, I setup 2 interfaces (duplicate elements). I defined one interface as a wall and the other as an interface. It did not run. Anything that I am missing?

 

Thanks,

 

AK.

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Answers

  • ydigit
    ydigit
    Altair Employee
    edited April 2020

    Please activate Turbulence (Spalart Allamaras) and then surface_film_coefficient  will be written out for post processing (in HyperView or AcuFieldView) or can be visualized even as a 'live' integrated scalar value in AcuProbe. 

  • Akhilesh Katipally
    Akhilesh Katipally New Altair Community Member
    edited April 2020

    Will that model work even when I know the flow is going to be Laminar?

     

    Just for my understanding, with Laminar flow, heat was being exchanged between the 2 domains. We need to turn on turbulence only to get the results output. is my understanding correct?

     

    Thanks,

     

    AK.

  • acupro
    acupro
    Altair Employee
    edited April 2020

    Yes - there is still heat transfer between the two volumes - the surface-film-coefficient output requires a turbulent flow solution.  You could also calculate your own definition for heat transfer coefficient once you have the other data.

     

    Second part of your initial question - please review the HyperMesh option for tutorial ACU-T: 3100 Conjugate Heat Transfer in a Mixing Elbow.  AcuSolve would use one set of nodes shared by both fluid and solid element sets.  One surface would be defined attached to the fluid volume, and the other attached to the solid volume, but both would use the same set of nodes.  Both could be defined as Wall BC - in fact, you wouldn't necessarily need the BC on the surface attached to the solid.  Neither should be tagged as Interface Surface - as there is one set of nodes shared by the two volumes.

  • Akhilesh Katipally
    Akhilesh Katipally New Altair Community Member
    edited April 2020

    Thanks for the reply, AcuPro. Do you have a pdf or help document that shows how to calculate HTCs with a constant reference temperature. The outputs I currently have are attached. I would need Heat Flow, Elemental Surface Area and the Elemental Surface temperature along with a known reference temperature to calculate HTCs with a constant temperature. I have the Surface temperature results, How Do I get the Heat Flow and Surface Area or the Elemental Heat Flux?

     

    Is there any other way we can calculate?

     

    Thanks,

     

    AK.

     

    <?xml version="1.0" encoding="UTF-8"?>Current_Results.png

  • acupro
    acupro
    Altair Employee
    edited April 2020

    If you give a non-zero value to nodal_output_frequency in the SURFACE_OUTPUT command for the desired surfaces, you should also have access to nodal area and nodal heat flux.  Then you can plot nodal HTC:  h = Q / ( A * dT )  -  using nodal Q, A, and T.  It would be interesting to look at the differences between this method, and activating the S-A turbulence model to plot the default surface-film-coefficient.