Wall slip velocity function possible?

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hello,

 

I will soon study the behaviour of HDPE melt which exhibits slip at walls. A few questions arise regarding this, mainly and most importantly how to implement a wall function allowing slip following a certain law. I could not find an option to use a UDF for walls. Is this at all possible in Acusolve 2017.1? Modelling another property of HDPE (viscosity model dependent on pressure and temperature) seems to be possible without a problem using UDFs.

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Answers

  • acupro
    acupro
    Altair Employee
    edited August 2017

    You do have the option to set a boundary to slip instead of wall, but I'm not sure about using UDF for that.  Can you provide some additional information about what you are attempting to simulate?  Are you by chance performing extrusion analysis?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited October 2017

    Hi,

     

    sorry for the late reply, I forgot this topic. I want to simulate the flow of molten HDPE which exhibits slip between the fluid and the wall following a certain function depending on the wall shear stress. A simple BC won't do it for this type of BC since either slip or no slip are available as options and none of those satisfy the real behaviour close enough. If interested, you can take a look here: https://www.researchgate.net/publication/251585191_Slip_effects_in_HDPE_flows

     

    I got a reply from the Altair support team, it is possible to implement this using advanced options like tangential traction, although I don't know yet if it will be possible to use the way I need it to.

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