In test experiments, we saw that if a water bottle suddenly accelerates (may be due to impact) then at some critical acceleration water cavitates. My work is to do some CFD simulation to find the pressure profile (vs acceleration) and if possible then to simulate cavitating bubble formation. Now in theory, fluid in metastable state can have "negative pressure" (tension) which leads to cavitation (bubble formation). In literature and after our experiments, when we did the math, we predicted that at around -120kPa cavitation will occur. Remember that this is not vacuum pressure ( or less than atm pr.).

Now my question regarding FLUENT. In FLUENT I set the Operating pressure to be 101325 Pa and I also limit pressure (abs) to 1 Pa. Since in FLUENT, gage pressure is, P (gage) = P (abs) - P (opt). Now based on that the min. gage pressure that can be captured is P (gage)_min = 1 - 101325 = -101324 Pa = -101 kPa. In FLUENT I shouldn't get anything below -101 kPa. But after the simulation when I am plotting P (gage) over time for a point (using CFD-Post) I am getting minimum P (gage) = -400 kPa.

First question: How FLUENT can have -400 kPa? Shouldn't it give me error while running saying, "min pressure limited to 1 Pa" or something like that?

Second question: Can (somehow) FLUENT actually simulate negative pressure (I meant tension)?