Evolution of Specific volume of wet saturated steam -thermodynamics :
Specific volume of wet saturated steam (V_{wet})
It is volume occupied by unit mass of wet saturated steam corresponding to given pressure of steam generation.
Sp. volume of wet saturated steam can be given by
Vwet = volume occupied by 'x' kg dry saturated steam + volume occupied by (1 - x) kg. water, here,
x = dryness fraction of the wet saturated steam.
Let v_{g} = specific volume of dry saturated steam in m^{3}/kg corresponding to the given pressure of wet saturated steam.
v_{f } = sp. volume of water in m3/kg corresponding to given pressure of wet saturated steam. Then,
V_{wet} = x.vg + (1 - x) v_{f} m3/kg.
As (1 - x) v_{f} is very small compared to x.v_{g} , it is neglected.
[Average value of v_{f} = 0.001 m^{3}/kg upto atmospheric pressure].
Thus,
V_{wet} = xvg m^{3}/kg.