In-flight dissipation as a mechanism to suppress Fermi acceleration.

Some dynamical properties of time-dependent driven elliptical-shaped billiards are studied. It was shown that for conservative time-dependent dynamics the model exhibits Fermi acceleration [Phys. Rev. Lett. 100, 014103 (2008).] On the other hand, it was observed that damping coefficients upon collisions suppress such a phenomenon [Phys. Rev. Lett. 104, 224101 (2010)]. Here, we consider a dissipative model under the presence of in-flight dissipation due to a drag force which is assumed to be proportional to the square of the velocity of the particle. Our results reinforce that dissipation leads to a phase transition from unlimited to limited energy growth. The behavior of the average velocity is described using scaling arguments.