thermo/volume.py
def Yamada_Gunn(T, Tc, Pc, omega):
    r'''Calculates saturation liquid volume, using Yamada and Gunn CSP method
    and a chemical's critical properties and acentric factor.

    The molar volume of a liquid is given by:

    .. math::
        V_s = \frac{RT_c}{P_c}{(0.29056-0.08775\omega)}^{[1+(1-{T/T_c})^{2/7}]}

    Units are in m^3/mol.

    Parameters
    ----------
    T : float
        Temperature of fluid [K]
    Tc : float
        Critical temperature of fluid [K]
    Pc : float
        Critical pressure of fluid [Pa]
    omega : float
        Acentric factor for fluid, [-]

    Returns
    -------
    Vs : float
        saturation liquid volume, [m^3/mol]

    Notes
    -----
    This equation is an improvement on the Rackett equation.
    This is often presented as the Rackett equation.
    The acentric factor is used here, instead of the critical compressibility
    A variant using a reference fluid also exists

    Examples
    --------
    >>> Yamada_Gunn(300, 647.14, 22048320.0, 0.245)
    2.1882836429895796e-05

    References
    ----------
    .. [1] Gunn, R. D., and Tomoyoshi Yamada. "A Corresponding States
        Correlation of Saturated Liquid Volumes." AIChE Journal 17, no. 6
        (1971): 1341-45. doi:10.1002/aic.690170613
    .. [2] Yamada, Tomoyoshi, and Robert D. Gunn. "Saturated Liquid Molar
        Volumes. Rackett Equation." Journal of Chemical & Engineering Data 18,
        no. 2 (1973): 234-36. doi:10.1021/je60057a006
    '''
    return R*Tc/Pc*(0.29056 - 0.08775*omega)**(1 + (1 - T/Tc)**(2/7.))
def Yamada_Gunn(T, Tc, Pc, omega):
    r'''Calculates saturation liquid volume, using Yamada and Gunn CSP method
    and a chemical's critical properties and acentric factor.

    The molar volume of a liquid is given by:

    .. math::
        V_s = \frac{RT_c}{P_c}{(0.29056-0.08775\omega)}^{[1+(1-{T/T_c})^{2/7}]}

    Units are in m^3/mol.

    Parameters
    ----------
    T : float
        Temperature of fluid [K]
    Tc : float
        Critical temperature of fluid [K]
    Pc : float
        Critical pressure of fluid [Pa]
    omega : float
        Acentric factor for fluid, [-]

    Returns
    -------
    Vs : float
        saturation liquid volume, [m^3/mol]

    Notes
    -----
    This equation is an improvement on the Rackett equation.
    This is often presented as the Rackett equation.
    The acentric factor is used here, instead of the critical compressibility
    A variant using a reference fluid also exists

    Examples
    --------
    >>> Yamada_Gunn(300, 647.14, 22048320.0, 0.245)
    2.1882836429895796e-05

    References
    ----------
    .. [1] Gunn, R. D., and Tomoyoshi Yamada. "A Corresponding States
        Correlation of Saturated Liquid Volumes." AIChE Journal 17, no. 6
        (1971): 1341-45. doi:10.1002/aic.690170613
    .. [2] Yamada, Tomoyoshi, and Robert D. Gunn. "Saturated Liquid Molar
        Volumes. Rackett Equation." Journal of Chemical & Engineering Data 18,
        no. 2 (1973): 234-36. doi:10.1021/je60057a006
    '''
    return R*Tc/Pc*(0.29056 - 0.08775*omega)**(1 + (1 - T/Tc)**(2/7.))
r'''Calculates saturation liquid volume, using Yamada and Gunn CSP method
    and a chemical's critical properties and acentric factor.

    The molar volume of a liquid is given by:

    .. math::
        V_s = \frac{RT_c}{P_c}{(0.29056-0.08775\omega)}^{[1+(1-{T/T_c})^{2/7}]}

    Units are in m^3/mol.

    Parameters
    ----------
    T : float
        Temperature of fluid [K]
    Tc : float
        Critical temperature of fluid [K]
    Pc : float
        Critical pressure of fluid [Pa]
    omega : float
        Acentric factor for fluid, [-]

    Returns
    -------
    Vs : float
        saturation liquid volume, [m^3/mol]

    Notes
    -----
    This equation is an improvement on the Rackett equation.
    This is often presented as the Rackett equation.
    The acentric factor is used here, instead of the critical compressibility
    A variant using a reference fluid also exists

    Examples
    --------
    >>> Yamada_Gunn(300, 647.14, 22048320.0, 0.245)
    2.1882836429895796e-05

    References
    ----------
    .. [1] Gunn, R. D., and Tomoyoshi Yamada. "A Corresponding States
        Correlation of Saturated Liquid Volumes." AIChE Journal 17, no. 6
        (1971): 1341-45. doi:10.1002/aic.690170613
    .. [2] Yamada, Tomoyoshi, and Robert D. Gunn. "Saturated Liquid Molar
        Volumes. Rackett Equation." Journal of Chemical & Engineering Data 18,
        no. 2 (1973): 234-36. doi:10.1021/je60057a006