Recreation of phi file, icoFoam
 

Hi all,

I have a question about the phi file created in the time directories during an icoFoam run.

I understand it to be a flux field through cell surfaces. It is generated if not present at time 0. [But I'm unclear on what is fluxing here, with units of m^3 / s].

It will also be re-generated if it is deleted after the simulation has started, though I get different results in this case.

For example, if I start a simulation and run it for, say, 0.5 seconds. At this point I either delete the phi file in directory 0.5 seconds, or I don't. Run both cases until 1.0 seconds. The analysis in which the phi file was deleted states that the phi file is being re-created: "Reading/calculating face flux field phi" and in deed in the next step 0.51 directory, it is present.

But the results (velocity, pressure) are significantly different at time 1.0.

So my questions are:

1) what does the phi file represent
2) why is it not recreated identically if it is not present after a restart
3) is there any way to have it recreated so that the analysis is identical

Thanks for your help,
Madeleine