Calculate Specific Entropy of Steam: 2MPa, 0.63 Dryness Fraction

[morry]

Ok, using steam tables, calculate the specific entropy of steam with dryness fraction 0.63 and pressure of 2MPa.

Can someone suggest how Id go about this?

Thanks.

 

[Astronuc]

If it has a quality (dryness fraction), x = 0.63, it is saturated steam at 2 MPa.

let y be a property, e.g. specific volume, v, specific enthalpy, h, specific internal energy, u, or specific entropy, s.

In a two phase system, each phase has these properties,

y_f or y_l , where f denotes fluid and l liquid

and

y_g or y_v , where g denotes gas and v vapor.


The property of the mixture is just the mass weighted sum of the liquid and vapor property.

y = (1-x) y_f + x y_g, or

y = y_f + x y_fg,

where y_fg = y_g - y_f

 

[morry]

Thanks Astronuc, I forgot that you could find entropy on the tables.