Is this mandatory to use SI units in HyperWorks CFD, or we can use other sets of unit?

James Lewis
James Lewis Altair Community Member
edited January 2023 in Community Q&A

Hi,

 

I'm wondering that is this mandatory for use to use SI units in HyperWorks CFD.

Or we can other sets of unit from below:

image

Best Answer

  • ydigit
    ydigit
    Altair Employee
    edited January 2023 Answer ✓

    If you want to use units for AcuSolve setup, then SimLab offers you the freedom to work with units. 

    Regarding HWCFD comments above are relevant. Also rotation is rad/s and not rpm. 

     

Answers

  • Jagan Adithya Elango
    Jagan Adithya Elango Altair Community Member
    edited December 2022

    You can follow any set of units, just make sure you are consistent with that particular set of units. 

  • Alexandru-Ionel Constantin
    Alexandru-Ionel Constantin Altair Community Member
    edited December 2022

    Hi James Lewis, 

     

    At the moment in HyperWorks CFD (like AcuSolve - the solver itself) there is no concept of units. 

    You need to specify a consistent set of units.  If you're working in MKS - mass in kg, distances/lengths in meters, temperatures in Kelvin, time in seconds, density in kg/m^3, the pressure unit is Pa, etc.

     

    Best regards,

    Alexandru

  • acupro
    acupro
    Altair Employee
    edited January 2023

    As others have stated - just make sure everything is consistent - distances, material properties, boundary conditions, etc.  It's a good practice to measure some known features to make sure of the units after importing the geometry.  Then make sure all other quantities have values that represent a consistent set of units - consistent with the dimensions' units.  You can also indicate the units for the geometry during the import process, and/or scale the model after import.

  • ydigit
    ydigit
    Altair Employee
    edited January 2023 Answer ✓

    If you want to use units for AcuSolve setup, then SimLab offers you the freedom to work with units. 

    Regarding HWCFD comments above are relevant. Also rotation is rad/s and not rpm.