Master Ott

I'm looking for an equation to find pressure as a function of time in a 10 cubic inch tank being filled from a 120 psi source through a valve with flow coeficient Cv=0.28, and a 2.5mm orifice size. I think that ultimately the answer comes from Navier Stokes equation, but I'm hoping someone can help me find a simplification that will work for my problem. Suggestions appreciated! P.S. I need to account for compressibility, and viscous flow