def Sherwood(K, L, D):
    """Calculates Sherwood number `Sh` for a mass transfer coefficient `K`,
    characteristic length `L`, and diffusivity `D`.

    .. math::
        Sh = \\frac{KL}{D}

    Parameters
    ----------
    K : float
        Mass transfer coefficient, [m/s]
    L : float
        Characteristic length, no typical definition [m]
    D : float
        Diffusivity of a species [m/s^2]

    Returns
    -------
    Sh : float
        Sherwood number, [-]

    Notes
    -----

    .. math::
        Sh = \\frac{\\text{Mass transfer by convection}}
        {\\text{Mass transfer by diffusion}} = \\frac{K}{D/L}

    Examples
    --------
    >>> Sherwood(1000., 1.2, 300.)
    4.0

    References
    ----------
    .. [1] Green, Don, and Robert Perry. Perry's Chemical Engineers' Handbook,
       Eighth Edition. McGraw-Hill Professional, 2007.
    """
    return K * L / D
