Farhang Ghasemi Afshar

The Theory of Acoustic Resonance and Acoustic Instability in HID Lamps

Abstract This paper reviews the current state of knowledge of acoustic instabilities in HID lamps. The phenomenon of acoustic instability has been investigated during the last four decades. However the exact physical background of this effect is still unclear. Based on the theory of acoustic streaming, a new explanation of the physical reasons for the excitation of acoustic instabilities and the temporal response of the discharge is given. To support the discussed hypothesis a real case of acoustic instability is investigated. It is shown that this hypothesis is able to explain some behavior of the lamp discharge when an acoustic resonance is excited.