def voidage_Benyahia_Oneil_cylindrical(Dpe, Dt, sphericity):
    """Calculates voidage of a bed of cylindrical uniform particles
    packed into a bed or tube of diameter `Dt`, with equivalent sphere diameter
    `Dpe`. Shown in [1]_, and cited by various authors. Correlations exist
    also for spheres, solid cylinders, hollow cylinders, and 4-hole cylinders.
    Based on a series of physical measurements.

    .. math::
        \\epsilon = 0.373+\\frac{1.703}{\\left(\\frac{d_{cyl}}{d_p}+0.611\\right)^2}

    Parameters
    ----------
    Dpe : float
        Equivalent spherical particle diameter (diameter of a sphere with the 
        same volume), [m]
    Dt : float
        Diameter of the tube, [m]
    sphericity : float
        Sphericity of particles in bed []

    Returns
    -------
    voidage : float
        Void fraction of bed packing []

    Notes
    -----
    Average error 1.6%; 1.7 < ratio < 26.3.

    Examples
    --------
    >>> voidage_Benyahia_Oneil_cylindrical(Dpe=.01, Dt=.1, sphericity=.6)
    0.38812523109607894

    References
    ----------
    .. [1] Benyahia, F., and K. E. O’Neill. "Enhanced Voidage Correlations for
       Packed Beds of Various Particle Shapes and Sizes." Particulate Science
       and Technology 23, no. 2 (April 1, 2005): 169-77.
       doi:10.1080/02726350590922242.
    """
    return 0.373 + 1.703 / (Dt / Dpe + 0.611) ** 2
