def Ceylan(Re):
    r'''Calculates drag coefficient of a smooth sphere using the method in
    [1]_ as described in [2]_.

    .. math::
        C_D = 1 - 0.5\exp(0.182) + 10.11Re^{-2/3}\exp(0.952Re^{-1/4})
        - 0.03859Re^{-4/3}\exp(1.30Re^{-1/2})
        + 0.037\times10^{-4}Re\exp(-0.125\times10^{-4}Re)
        -0.116\times10^{-10}Re^2\exp(-0.444\times10^{-5}Re)

    Parameters
    ----------
    Re : float
        Particle Reynolds number of the sphere using the surrounding fluid
        density and viscosity, [-]

    Returns
    -------
    Cd : float
        Drag coefficient [-]

    Notes
    -----
    Range is 0.1 < Re <= 1E6
    Original article reviewed.

    Examples
    --------
    >>> Ceylan(200.)
    0.7816735980280175

    References
    ----------
    .. [1] Ceylan, Kadim, Ayşe Altunbaş, and Gudret Kelbaliyev. "A New Model
       for Estimation of Drag Force in the Flow of Newtonian Fluids around
       Rigid or Deformable Particles." Powder Technology 119, no. 2-3
       (September 24, 2001): 250-56. doi:10.1016/S0032-5910(01)00261-3.
    .. [2] Barati, Reza, Seyed Ali Akbar Salehi Neyshabouri, and Goodarz
       Ahmadi. "Development of Empirical Models with High Accuracy for
       Estimation of Drag Coefficient of Flow around a Smooth Sphere: An
       Evolutionary Approach." Powder Technology 257 (May 2014): 11-19.
       doi:10.1016/j.powtec.2014.02.045.
    '''
    Cd = (1 - 0.5*exp(0.182) + 10.11*Re**(-2/3.)*exp(0.952*Re**-0.25)
    - 0.03859*Re**(-4/3.)*exp(1.30*Re**-0.5) + 0.037E-4*Re*exp(-0.125E-4*Re)
    - 0.116E-10*Re**2*exp(-0.444E-5*Re))
    return Cd
r'''Calculates drag coefficient of a smooth sphere using the method in
    [1]_ as described in [2]_.

    .. math::
        C_D = 1 - 0.5\exp(0.182) + 10.11Re^{-2/3}\exp(0.952Re^{-1/4})
        - 0.03859Re^{-4/3}\exp(1.30Re^{-1/2})
        + 0.037\times10^{-4}Re\exp(-0.125\times10^{-4}Re)
        -0.116\times10^{-10}Re^2\exp(-0.444\times10^{-5}Re)

    Parameters
    ----------
    Re : float
        Particle Reynolds number of the sphere using the surrounding fluid
        density and viscosity, [-]

    Returns
    -------
    Cd : float
        Drag coefficient [-]

    Notes
    -----
    Range is 0.1 < Re <= 1E6
    Original article reviewed.

    Examples
    --------
    >>> Ceylan(200.)
    0.7816735980280175

    References
    ----------
    .. [1] Ceylan, Kadim, Ayşe Altunbaş, and Gudret Kelbaliyev. "A New Model
       for Estimation of Drag Force in the Flow of Newtonian Fluids around
       Rigid or Deformable Particles." Powder Technology 119, no. 2-3
       (September 24, 2001): 250-56. doi:10.1016/S0032-5910(01)00261-3.
    .. [2] Barati, Reza, Seyed Ali Akbar Salehi Neyshabouri, and Goodarz
       Ahmadi. "Development of Empirical Models with High Accuracy for
       Estimation of Drag Coefficient of Flow around a Smooth Sphere: An
       Evolutionary Approach." Powder Technology 257 (May 2014): 11-19.
       doi:10.1016/j.powtec.2014.02.045.