def METHOD_NAME(self):
    r"""
    Calculate entropy balance of turbomachine.
    Note
    ----
    The entropy balance makes the follwing parameter available:
    .. math::
        \text{S\_irr}=\dot{m} \cdot \left(s_\mathrm{out}-s_\mathrm{in}
        \right)\\
    """
    self.S_irr = self.inl[0].m.val_SI * (
        self.outl[0].s.val_SI - self.inl[0].s.val_SI)