Oil Inverse Linear Density model¶
The inverse linear density model requires the input of a reference density, pressure and temperature, and compressibility and expansion coefficients. See example below:
EOS OIL
FORMULA_WEIGHT 508.0d0
DENSITY INVERSE_LINEAR
REFERENCE_VALUE 995.98d0 !den0 [kg/m3]
PRES_REF_VALUE 1.13d5 !p0 [Pa]
TEMP_REF_VALUE 21.d0 !T0 [°C]
COMPRESS_COEFF 5.63d-10 !cp [1/Pa]
THERMAL_EXPANSION_COEFF 8.480d-4 !ct [1/°C]
END
ENTHALPY LINEAR_TEMP 1.d3 !c oil [J/kg/°C]
VISCOSITY CONSTANT 3.0d-3 ![Pa.s]
END
The mathematical expression of the model is reported below:
\[\rho( p ,T )= \frac{\rho_0}{ [1−c_p ( p−p_0 )] [1+c_T (T −T_0 )]}\]
where:
\[\begin{split}\begin{split}
& p &= \mbox{pressure [Pa]} \\
&T &= \mbox{temperature [°C]} \\
&\rho_0 &= \mbox{reference density [kg/m3]} \\
&p_0 &= \mbox{reference pressure [Pa]} \\
&T_0 &=\mbox{reference temperatures [°C]} \\
&C &=\mbox{compressibility coefficient [kg/m3/Pa]} \\
&E &=\mbox{thermal expansion coefficient [kg/m3/°C]}
\end{split}\end{split}\]
Units cannot be specified, therefore values must be entered in the units prescribed above.