Accession Number : AD0699804

Title :   RESONANT THERMAL-ACOUSTIC OSCILLATIONS.

Descriptive Note : Technical rept.,

Corporate Author : LEHIGH UNIV BETHLEHEM PA CENTER FOR THE APPLICATION OF MATHEMATICS

Personal Author(s) : Mortell,Michael P.

Report Date : OCT 1969

Pagination or Media Count : 37

Abstract : Small amplitude resonant motions of an inviscid, polytropic gas, contained in a tube of finite length, are investigated. It is postulated that motion of the gas may be represented as the super-position of two small amplitude simple waves which interact only at the boundaries. As a result, the problem reduces to solving a nonlinear difference equation, and this is effected on the basis that the solution is in the neighborhood of a linear standing wave. A consequence is that waves progress as acoustic waves, but the signal carried is determined by a nonlinear equation. The problems considered are the determination of the motion of the gas which is being forced at a resonant frequency at one end of a tube, while the other end may be open or closed. Self-sustained oscillations for these cases are also treated. For these resonant motions, the amplitude of the motion at particles away from the ends is greater than that of the driving mechanism. When the end of the tube is closed, shocks are a feature of the solution. For an open end, the motion is continuous. (Author)

Descriptors :   (*ACOUSTICS, BOUNDARY VALUE PROBLEMS), SHOCK WAVES, RESONANCE, OSCILLATION, PROPAGATION, THERMAL PROPERTIES, GASES, NONLINEAR DIFFERENTIAL EQUATIONS, APPROXIMATION(MATHEMATICS)

Subject Categories : Acoustics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE