Detailed Description

This is generalized class that can be used to manage an ancillary curve, here they are ancillary curves for saturation pressure, density, enthalpy, entropy.

The form of the ancillary equation can take one of a number of forms:

a) So-called "exponential" form (type = TYPE_EXPONENTIAL) that has a form like

\[ y = y_c\exp\left(\frac{T_c}{T}\sum(n_i \theta^{t_i})\right) \]

or

\[ y = y_c\exp\left(\sum(n_i \theta^{t_i})\right) \]

b) A non-exponential form (type = TYPE_NOT_EXPONENTIAL) that has a form of

\[ y = y_c\left(1+\sum_i(n_i\theta^t_i)\right) \]

with

\[ \theta = \left(1-\frac{T}{T_c}\right) \]

which is conveniently equal to zero at the critical point

c) Rational polynomial form (type = TYPE_RATIONAL_POLYNOMIAL) that has a form of

\[ y = \frac{\sum_iA_iT^i}{\sum_iB_iT^i}\]

where i is an integer, and the coefficients are in increasing order in both numerator and denominator

#include <Ancillaries.h>

Public Member Functions
	SaturationAncillaryFunction (rapidjson::Value &json_code)

bool	enabled (void)
	Return true if the ancillary is enabled (type is not TYPE_NOT_SET)

CoolPropDbl	get_max_abs_error ()
	Get the maximum absolute error for this fit. More...

double	evaluate (double T)
	Evaluate this ancillary function, yielding for instance the saturated liquid density. More...

double	invert (double value, double min_bound=-1, double max_bound=-1)
	Invert this ancillary function, and calculate the temperature given the output the value of the function. More...

double	get_Tmin (void)
	Get the minimum temperature in K.

double	get_Tmax (void)
	Get the maximum temperature in K.

Member Function Documentation

◆ evaluate()

double CoolProp::SaturationAncillaryFunction::evaluate ( double T )

Evaluate this ancillary function, yielding for instance the saturated liquid density.

Parameters

T	The temperature in K

Returns: y the value of the ancillary function at temperature T

◆ get_max_abs_error()

CoolPropDbl CoolProp::SaturationAncillaryFunction::get_max_abs_error ( )

inline

Get the maximum absolute error for this fit.

Returns: max_abs_error the maximum absolute error for ancillaries that are characterized by maximum absolute error

◆ invert()

double CoolProp::SaturationAncillaryFunction::invert	(	double	value,
		double	min_bound = `-1`,
		double	max_bound = `-1`
	)

Invert this ancillary function, and calculate the temperature given the output the value of the function.