The role played by acoustic waves in one-dimensional oscillatory instabilities is investigated at moderate overdrives. The mechanism responsible for the instability is similar to the quasi-isobaric one at high over-drives. The overall effect of pressure fluctuations is stabilizing and decreases the oscillatory frequency at the instability threshold. A nonlinear integral equation for the evolution of the detonation velocity is obtained as an asymptotic solution of the reactive Euler equations.

• Received 18 October 1995

DOI:https://doi.org/10.1103/PhysRevE.53.4778