PPT Slide
Total volume is the sum of liquid volume and vapor volume:
V = Vf + Vg = mfvf + mgvg, where v is the specific volume or 1/r.
V/m = v = Vf/m + Vg/m = (mf/m)vf + (mg/m)vg
= [(m-mg)/m]vf + (mg/m)vg
= (1-x)vf+xvg= vf + x(vg-vf) = vf + xvfg, where vfg = vg-vf
Similarly, all other saturated thermodynamic properties can be
expressed in the same manner:
Ex: internal energy: u = (1-x)uf+xug= uf + x(ug-uf) = uf + xufg
since U = Uf + Ug = mfvf + mgvg