LiquidMixtureDensity
LiquidMixtureDensity returns the density of a liquid mixture consisting of 2 to 6 fluids. The units of the inputs and the resulting density depend on the EES unit system settings. It is a function and accessed with the following format.
rho=LiquidMixtureDensity(N, F$[1..N], T, P, x[1..N])
where
rho is the liquid density in units of kg/m^3 or kmol/m3 in SI units or lbm/ft^3 or lbmol/ft^3 in English units.
N is the number of fluids (between 2 and 6)
F$[1..N] is a string array consisting of the names of the fluids. These fluid names must be recognized by EES as Real fluids or Ideal gases
T is the temperature in units of (C, K, F, or R)\
P is the pressure in units of (Pa, kPa, bar, MPa, psia, or atm)
x[1.N] is an array consisting of N mole or mass fractions. Mass fractions are expected if the unit system setting is for mass.
Notes:
1. This function uses the Peng-Robinson equation of state with empirical adjustments to estimate the density. The accuracy depends on many factors including the polarity and difference in molar mass of the components as well as the temperature and pressure. A result within 5% of the actual value is expected.
2. The fluid names must be recognized as the names of Real fluids or Ideal Gases, which are listed here. Note that refrigerant mixtures (R4xx and R5xx) can not be provided. Incompressible fluids that provide critical constants may also be used. The fluids are primarily the incompressible organic liquids.
3. The function assumes a liquid phase exists at the specified temperature and pressure. It does not check to see if the state is two-phase or vapor
4. The function assumes that the fluids are miscible. It does not check for liquid-liquid state.
Examples:
$UnitSystem SI K kPa molar
$VarInfo rho Units=kmol/m^3
F$[1]='Methane'
F$[2]='Propane'
T=310.92 [K]
P=206.84 [bar]*Convert(bar,kPa)
x[1]=0.5
x[2]=1-x[1]
N=2
rho=LiquidMixtureDensity(N,F$[1..N],T,P,x[1..N])
{Solution: rho=12.52 [kmol/m^3]
The experimental value is 12.604 as reported by Poling, Prausnitz, O'Connell, Properties of Liquid and Gases. McGraw-Hill, 5th ed, 2001
}
$UnitSystem Eng F atm molar
$VarInfo rho units=lbmol/ft^3
F$[1]='ethane'
F$[2]='propane'
F$[3]='methane'
T=-100 [F]
P=20 [atm]
x[1]=0.5
x[2]=0.4
x[3]=0.1
N=3
rho=LiquidMixtureDensity(N,F$[1..N],T,P,x[1..N])
{Solution: rho=rho=1.017 [lbmol/ft^3]
REFPPROP 10 returns a density of 1.014 lbmol/ft^3}