.. _oil_enth_quad_sec: Oil quadratic enthalpy ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ The oil enthalpy can be modelled using the present quadratic model which accounts for temperature dependence only. Two reference temperatures and two coefficients need to be entered. See example below. :: EOS OIL DENSITY CONSTANT 734.29d0 !kg/m3 VISCOSITY CONSTANT 0.987d-3 ENTHALPY QUADRATIC_TEMP TEMP_REF_VALUES 15.5555556 15.5555556 ![°C] TEMP_COEFFICIENTS 1.653D3 4.001d0 ![J/kg °C] [J/(kg °C °C)] END END The mathematical expression of this model is given below .. math:: h(T )=c_{t,1} (T −T_1 )+ \frac{1}{2} c_{t,2} (T −T_2 )^2 where: .. math:: \begin{split} &h(T ) &= \mbox{oil enthalpy [J/kg]}\\ &T_1 &= \mbox{linear reference temperature [C]}\\ &c_{t,1} &= \mbox{linear dependency coefficient [J/(kg C)]}\\ &T_2 &= \mbox{quadratic reference temperature [C]}\\ &c_{t,2} &= \mbox{quadratic dependency coefficient [J/(kg C C)]} \end{split} Units cannot be specified, therefore values must be entered in the units prescribed above.