Standing acoustic waves in a confined, non-uniform gas

✍ Scribed by F.V. Bracco

• Publisher: Elsevier Science
• Year: 1975
• Tongue: English
• Weight: 467 KB
• Volume: 41
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1016/s0022-460x(75)80177-5

✦ Synopsis

Standing longitudinal acoustic waves in a non-uniform gas within a chamber are studied. Frequencies and wave forms are calculated for various types (linear and exponential) and degrees of non-uniformity in the speed of sound. Little changes in wave forms but significant changes in frequencies are computed. It is also shown that the simple method of computing these frequencies using only the local speed of sound gives practically the same results. The study consists of linearizing the conservation equations for acoustic perturbations of the steady state, of imposing the periodicity condition, and of solving some ordinary differential equations mostly by the power series method. The': original motivation for the study was provided by the problem of the high frequency combustion instability in rocket motors but other applications are indicated.