[kaifu]

Hi,

I have troubles in understanding the correction term in pressure equation.
For example in buoyantPimpleFoam,

        
fvScalarMatrix p_rghDDtEqn
(
    fvc::ddt(rho) + psi*correction(fvm::ddt(p_rgh))
  + fvc::div(phi)
);

where does the term psi*correction(fvm::ddt(p_rgh)) come from?
It seems like it origins from the difference between old value and current value of rho. But how about if we write the eqn as

        
fvScalarMatrix p_rghDDtEqn
(
    fvc::ddt(psi,p) 
  + fvc::div(phi)
);

Back to the correction part, why there is no term like

        
 p_rgh*correction(fvc::ddt(psi))

[pfhan]

Have you solved it?
I'm confused too. It should be related to the material differential of pressure, but I don't know how to get it in this particular form.