Beschreibung:
<jats:p>The problem called “high-frequency combustion instability in rocket motors” has been considered to be one in which the acoustics of the combustion chamber, nozzle, and flame front are significant for determining whether or not a motor will experience pressure oscillations of an acoustic type. To date, no theory has been developed for demonstrating the effects of the location and width of the flame front in the combustion chamber upon the occurrence of pressure oscillations of the longitudinal mode. In this paper, the rocket motor is treated as a constant-diameter duct with a finite width of combustion zone located between two uniform regions. It also is considered to have finite wave-transmission coefficients at the nozzle and the injector ends. For these conditions, stability criteria are established for the longitudinal mode of pressure oscillations. It is shown that, while the energy release rate per unit width of the combustion zone is significant in determining whether the motor will be stable, the location of the combustion zone in the motor, the over-all length of the motor, and the total amount of energy released also influence the stability of the motor in the longitudinal mode.</jats:p>