[RakeshRR]

Hello all,

I am going through some of the literature on Ghost Fluid method. In this method, the entropy of the ghost fluid are extrapolated from real fluid on the other side of the interface.

My question is on how to compute the entropy of the fluid with general EoS P = Function(Rho, internal energy) or specifically for Mie-Gruneisen or JWL-EoS.

And how do we calculate density, internal energy from extrapolated entropy(Pressure at point is known).

Thank you

[sbaffini]

Never worked on the ghost fluid method itself, only with ghost cells and immersed boundary methods using them. This is not going to help you, but:

- I found several approaches to deal with the thermodynamic state in ghost cells (most used isentropic or similar relations which would not apply in the real fluid)
- None of them had any justification, besides "trust me, it works"
- I soon realized that, at least for ghost cells (might be different for the ghost fluid method), the state in the ghost cells can't both be physical and locally accurate for your interpolation needs without arbitrary decisions.
- definitely abandoned any approach requiring extrapolations to fictitious states, especially thermodynamic ones
- live happily ever after

[RakeshRR]

Thank you, the reply @sbaffini.

I am planning to abandon the method for now, as the I realized the flux at the interface element might not be conserved.

I would also appreciate if you can point out any papers/method for Fluid/fluid interaction for compressible flow(Euler Equations).

Rakesh

[naffrancois]

Hello,

Have a look to the Diffuse Interface Method, there are some articles dealing with fully compressible multiphase mixtures with eos for combustion products such as JWL on this webpage:

http://www.rs2n.eu/html/publications.html#publications