Issue regarding Initial Velocity about an Axis in Radioss

Gaurav K
Gaurav K Altair Community Member
edited October 2020 in Community Q&A

I have defined initial velocity about an axis in radioss but the rotor gets expand due to given velocity i am unable to find the reason.

Please can u help me in this.

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Here is model and out file attached so it would be easy for you to find solution.

Unable to find an attachment - read this blog

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Answers

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited April 2020

    Try adopting the approach from Radioss example RD-E: 2300 Brake

    Unable to find an attachment - read this blog

  • Andy_20955
    Andy_20955 New Altair Community Member
    edited April 2020

    When the structure is rotating at very high speeds, it is necessary to include the centrifugal force field acting on the structure to correctly account for the initial stresses in the structure due to rotation.  Without those initial stresses, the rotor could expand as you described. 

    There is an example in the Radioss help about this,

    RD-E: 5500 Fan Blade Rotation Initialization and Impact. 

     

    Using /INIVEL/ROT/ with two engine files as in RD-E: 2300 Brake was an old method to define a rotational velocity about an axis before /INIVEL/AXIS existed in the Radioss stater. 

    You can also define an initial velocity in the engine file using, /INIV/AXIS/.  See example RD-E: 5500 Fan Blade Rotation Initialization and Impact for more details.

     

    Thanks,

    Andy

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