Water Saturation properties
Water Saturation properties
(OP)
In 1997 the International Association for Properties of water and steam (IAPWS) adopted the new industrial standard of (IAPWS-IF97) for thermodynamic properties of water and steam.
I need heat capacity Cp and speed of sound w for these point at saturation line or region 4
T,Kelvin , 622,623, 624 and 646,646.5 ,647
Thanks all
I need heat capacity Cp and speed of sound w for these point at saturation line or region 4
T,Kelvin , 622,623, 624 and 646,646.5 ,647
Thanks all





RE: Water Saturation properties
RE: Water Saturation properties
http://hydra.nat.uni-magdeburg.de/phys/PT5.html
Speed of sound can calculated with the gas laws.
Andreas
RE: Water Saturation properties
a=sqrt(kappa*R*T)
a= velocity of sound (m/s)
kappa=cp/cv ratio of specific heats (1)
R= gas constant (J/kg/°K)
T= temparatue (°K)
For example air 20°C (=293 °K):
kappa=1.4
T=293 °K
R=287 J/kg/°K
a=sqrt(1.4*293*287)
a=343.11 m/s
Good luck
Andreas
RE: Water Saturation properties
I know that many of the "ideal gas" assumptions are significantly in error for steam at or near saturation conditions. It seems to me that this could very well be the case for speed of sound (can't imagine why not) but I don't know for sure.
I advise some caution to you regarging the previous posts.
RE: Water Saturation properties
RE: Water Saturation properties
c^2=-v^2 (dp/dv) isentropic equation (1)
v is known from the sat temp or press.
To calculate dv/dp along an isentrope
v=vf+(So-Sf)*vfg/sfg equation (2)
But from Claus-Claper relation
dp/dT=sfg/vfg (3)
So that v=vf+(So-Sf)*dT/dp (4)
Take derivative of this last expression (with So know from the specified sat press or temp) with respect ot pressure
and equation (1) may be solved for sound speed.