[harsha_kulkarni]

Hello Friends,

I am using twophaseEulerFoam for simulation of Fluidized Bed. I want to know that what are the JohnsonJacksonCoeffs

{
Fr 0.05;
eta 2;
p 5;
phi 28.5;
}

Regards

Harshawardhan

[wyldckat]

Greetings Harshawardhan,

I was going to say that the source code has the answer, but: https://github.com/OpenFOAM/OpenFOAM...tionalStress.H

        //- Material constant for frictional normal stress
        dimensionedScalar Fr_;

        //- Material constant for frictional normal stress
        dimensionedScalar eta_;

        //- Material constant for frictional normal stress
        dimensionedScalar p_;

        //- Angle of internal friction
        dimensionedScalar phi_;

Only the last one is clear on what it is exactly. The first three seem consistent with the theoretical modelling for this kind of simulation.
A bit of research into this topic leads me to believe that they are all empirical model coefficients of the following bibliographic reference:

Johnson, P. C., and R. Jackson (1987), Frictional-collisional constitutive relations for granular materials, with application to plane shearing, Journal of Fluid Mechanics, 176, 67–93

Best regards,
Bruno

[dradenkovic]

If someone needs information about the aforementioned parameters, this reference could also be useful:

P. C. JOHNSON, P. NOTT , R. JACKSON, Frictional-collisional equations of motion for
particulate flows and their application to chutes, J . Fluid Mech. (1990), pp. 501-535

Starting from eq. (2.18).

Regards,
Darko