  Recently, strong coupling between non-Hermitian physical systems of different
nature is widely investigated due to it endows them with new properties. In
this work, we investigate the energy transport between strongly coupled
systems. We use a partial-secular approach for the description of an open
quantum system to investigate the system dynamics during the transition from a
weak to a strong coupling regime with an increase of coupling between
subsystems. On the example of strongly coupled two-level atoms, we show that
near the transition point enhancement of energy transport between the system
and reservoirs takes place. This manifests in the fact that energy flow
normalized to the coupling constant reaches the maximum both in the cases of
zero and non-zero frequency detuning. We show that maximization of normalized
energy flow can be used for the determination of the transition to the strong
coupling regime in the case of non-zero detuning when there is no clear
transition point from the weak to strong coupling regime. The suppression of
the energy flow at high relaxation is demonstrated.
