Porous media

I am doing a simulation  on capillary driven evaporator to get its temperature profile, its a porous media so there has to be an effective thermal conductivity. Based on porosity, solid material conductivity and working fluid conductivity fluent is by default taking volume average effective thermal conductivity i.e.,

k_eff=k_s(1-porosity) + porosity(k_l)

but this is over predicting the value so I want to use some other correlation i.e.,

k-eff=k_l(k_l/k_s)^-(1-porosity)^(0.6)

but there is no option to input effective thermal conductivity so if I am making a UDF then how to implement it.

Please help me with the solution I am really struggling with the problem

 

Comments

  • RobRob UKForum Coordinator
    edited January 2019

    You alter the conductivity in the materials panel. So you could make a new material for the porous zone and work out the correction factor to the solid conductivity which avoids the need for a UDF. 

  • Sahu007Sahu007 Member
    edited January 2019

    Okay I can consider this thing 

    Thanks for your suggestion

  • ABHAYABHAY Member
    edited February 2019

    I am doing simulation for two fluid in which there is requirment of rock properties  and main problem is to enter permeability of both fluid so suggest that how can enter this properties in fluent data base .

  • RobRob UKForum Coordinator
    edited February 2019

    For Eulerian multiphase you can enter the permeability (resistance) coefficients on a per phase basis. They're set in the cell zone panel as it's a porous property not a flowing material property. 

  • ABHAYABHAY Member
    edited February 2019

    sir actually my problem is that to to see the instability at the interface of oil water interface. when oil is extracted from the sea reserviour is main condition . please tell me the procedure for simulation in ansys fluent . and thank you for previous reply.

  • RobRob UKForum Coordinator
    edited February 2019

    You'll need to turn on the multifluid VOF then, and include the Corey models: you're going to struggle to see any instabilities as these tend to be at the micro-scale and we model formations at the bulk scale. 

  • ABHAYABHAY Member
    edited February 2019

    sir actually i am trying in vof model but problem comes at the interface where instability will not occur . I do not recognize the corey model in fluent so if it possible from this model then give the link to understand this model.

  • RobRob UKForum Coordinator
    edited February 2019

    Have a look in the documentation: 6.2.3.7.16. Specifying the Relative Permeability in the User's Guide (R19.2). 

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