variavel0=<b>FABIANO RIBEIRO DO VALE ALMEIDA</b> - mtaev@uol.com.br UNIVERSIDADE FEDERAL DE ENGENHARIA DE ITAJUBÁ
<b>Márcio Tadeu Almeida</b> - mtaev@uol.com.br Universidade Federal de Engenharia de Itajubá
<b>Abstract.</b> A vibration model of a single-degree-of-freedom mechanical system, describes the bechavior of self excited flow surge on ventilation system, where the volume flow rate is the time-dependent variable.. This model consist of a significant pressure drop into a large volume which act like a spring, the mass of gas in the connecting pipe which act like inertia, minor losses and pipe friction which acts like damping. Also shows that system will bee stable, when the performance curve slope is negative, and when the slope is positive, the system will be unstable and depending on system damping.
<b>Keywords.</b> Pulsation, Self-Excited, Vibration, Acoustic Ressonance.