def Eckert(V, Cp, dT):
    """Calculates Eckert number or `Ec` for a fluid of velocity `V` with
    a heat capacity `Cp`, between two temperature given as `dT`.

    .. math::
        Ec = \\frac{V^2}{C_p \\Delta T}

    Parameters
    ----------
    V : float
        Velocity of fluid, [m/s]
    Cp : float
        Heat capacity of the fluid, [J/kg/K]
    dT : float
        Temperature difference, [K]

    Returns
    -------
    Ec : float
        Eckert number []

    Notes
    -----
    Used in certain heat transfer calculations. Fairly rare.

    .. math::
        Ec = \\frac{\\text{Kinetic energy} }{ \\text{Enthalpy difference}}

    Examples
    --------
    >>> Eckert(10, 2000., 25.)
    0.002

    References
    ----------
    .. [1] Goldstein, Richard J. ECKERT NUMBER. Thermopedia. Hemisphere, 2011.
       10.1615/AtoZ.e.eckert_number
    """
    return V ** 2 / (Cp * dT)
