# Should the total pressure be the most negative value in a "negative pressure"-system?

(I didn't really have success in getting this answered on the Engineering-side so I'll try here)

I'm not very familiar with vacuum systems so this became a bit of an issue for me when I'm currently looking at some simulation values from a functionality someone (much more skilled than me) has programmed.

The result is P_tot = -253 Pa and P_static = -289 Pa

As P_tot = P_static + P_dynamic I would have imagined it to be the same for negative pressure system, as it is just a relative value, in other words that in those cases P_tot would be the most negative (the sum of the negative P_static and P_dynamic values).

I'm then currently wondering if I'm looking at a bug or there is something truly lacking in my understanding of these types of pressure systems and could someone clarify this for me in that case?

Dynamic pressure is $\frac{1}{2}\rho v^2$ which is positive definite. So the "total pressure" is always higher than the static pressure. Also, I assume you are referring to gauge pressure here, rather than absolute pressure (which is always positive).