Wall Thickness for RPI Wall Boiling Model

Dear all,

Please give me some strong justification for what is the difference in putting wall thickness in the simulation in terms of dealing with boiling heat transfer? I have some calculation for determining the difference between the outer wall temperature and inner wall temperature and the result is 32K. 

What will be the main effect if we don't put any wall thickness if the temperature difference is around 32K. Highly appreciated for your consideration.

Thank you,

Best Regards,

Luthfi Ady Farizan Haryoko

 

Comments

  • DrAmineDrAmine GermanyForum Coordinator
    edited February 2019
    Zero thickness wall is the default behaviour: No heat resistance so outer wall temperature is equal to inner wall temperature.
  • farizanluthfifarizanluthfi Member
    edited February 2019

    For this different is around 32K, is that necessary for me to build the wall thickness so there will be heat resistance that defines the different temperature between inner and outer wall temperature?

    Thank you,

    Best Regards,

    Luthfi Ady Farizan Haryoko

  • DrAmineDrAmine GermanyForum Coordinator
    edited February 2019
    Yes: 134 kJ/kg is the imbalance if you do not account for this temperature drop.
  • farizanluthfifarizanluthfi Member
    edited February 2019

    Okay, I will determine the wall thickness in the B.Cs of the Fluent. The thickness is about 3.5mm so I guess it would bring miscalculations if I didn't put it on my case.

    Thank you,

    Best Regards,

    Luthfi Ady Farizan Haryoko

  • farizanluthfifarizanluthfi Member
    edited February 2019

    I have tried your way for handling the boiling heat transfer case, but when I put default URF, it could get me diverged directly. Otherwise, if I alter the URF then the case is still running until 2000 iterations.

    Here is the URF that I used in my case:

    density = 1

    body forces = 0.5

    vap. mass = 0.5

    vol.fraction = 0.3

    turb. kinetic energy = 0.3

    turb. dissipation rate = 0.3

    turb. viscosity = 0.5

    energy = 0.6

    Highly appreciated for your kindly responses. Thank you.

    Best Regards,

    Luthfi Ady Farizan Haryoko

  • DrAmineDrAmine GermanyForum Coordinator
    edited February 2019
    Try if possible to ramp URFs and fluxes as your solution evolves.
  • farizanluthfifarizanluthfi Member
    edited February 2019

    Okay, I'll do my best then I will update it to you again.

    Thanks,

    Best Regards,

    Luthfi Ady Farizan Haryoko

  • DrAmineDrAmine GermanyForum Coordinator
    edited February 2019
    Mark this thread as solved select the the ansewer and update on your boiling case in the old thread.
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