Resumo:
The main objective of this dissertation is to study self-excited vibrations,
applied in rolls of paper machines, lathes and mainly in a ventilation system.
The study also contains a model of a self-excited fluid, that in a certain
critical flow rate the frequency of pulsation of the pressure coincides with the
frequency natural acoustics of the tube, generating an acoustic resonance.
therefore, the model is based on an acoustic resonator of Helmohltz operating in
an unstable condition.
With the system in acoustic resonance will be measured: the induced self excited vibration of the tube, as well as the pressure oscillation.
