Variable Total Pressure Goal for a Water Jet Simulation

I am analyzing a water jet with flow simulation to correlate the results to a series of physical tests we performed. I have run many versions of this study and found that Total Pressure at the exit of the orifice traces the physical results best.

I have a Static Pressure inlet BC of 10,000psi and a Volume Flow outlet BC of 40gpm. I have an Avg Total Pressure surface goal on an invisible surface at the orifice exit.

When I rerun the study, without changing anything, it does not produce the same average total pressure value. It is within 25psi usually. This is only an issue because some of the comparative results can fall in this same tolerance so the results could show a less effective setup being better. The Reynolds Number is around 1,000,000 at the orifice.

I have tried a variety of goals and time dependent studies and nothing has pulled it in much closer.

Are there any setup changes I can make to get consistent results? Or even other goals or output results I should look at? Is this with in the programs capacity?

Any suggestions are appreciated.

Thanks,

-Joe

SolidworksFlow Simulation