Accession Number : AD0727316

Title :   Propagation of Finite Amplitude Acoustic Waves in Nonlinear Relaxing Fluids.

Descriptive Note : Technical rept.,

Corporate Author : DREXEL UNIV PHILADELPHIA PA

Personal Author(s) : Klinman,Richard ; Kraus,Lester A.

Report Date : 22 JUN 1971

Pagination or Media Count : 222

Abstract : The hydrodynamic equations for relaxing fluids are used to derive the evolutionary properties of longitudinal plane waves of finite amplitude in dispersive and dissipative media. The regimes of uniform and secular perturbation solutions, representing either shock free or possibly shock like solutions, are determined from the equations with no restriction on the dispersion number. Solutions are calculated to second order to demonstrate the main features of the progressive wave distortion in nonlinear relaxing media. Heuristic theories using an equivalent viscous model of relaxing media are evaluated through comparison with the correct relaxation results. A consistent consideration of the perturbation method leads to a representation of the thermal state functions containing many parameters of nonlinearity which include the well known B/A parameter. Finally, through recourse to the theory of characteristics it is demonstrated that, unlike thermoviscous media, relaxing media may sustain true discontinuities in the flow similar to those occurring in the nondissipative Riemann solution. (Author)

Descriptors :   (*SOUND TRANSMISSION, HYDRODYNAMICS), EQUATIONS OF MOTION, VISCOSITY, VISCOELASTICITY, THERMAL PROPERTIES, PERTURBATION THEORY, HARMONIC ANALYSIS, THESES

Subject Categories : Acoustics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE