Author(s)

Eugen Mamontov^1*, Viktor Berbyuk²

¹Utilization Group, Department of Research and Development, Foundation Chalmers Industrial Technology, Gothenburg, Sweden.
²Division of Dynamics, Department of Applied Mechanics, Chalmers University of Technology, Gothenburg, Sweden.

The work deals with a mathematical model for real-time acoustic monitoring of material parameters of media in multi-state viscoelastic engineering systems continuously operating in irregular external environments (e.g., wind turbines in cold climate areas, aircrafts, etc.). This monitoring is a high-reliability time-critical task. The work consistently derives a scalar wave PDE of the Stokes type for the non-equilibrium part (NEP) of the average normal stress in a medium. The explicit expression for the NEP of the corresponding pressure and the solution-adequateness condition are also obtained. The derived Stokes-type wave equation includes the stress relaxation time and is applicable to gases, liquids, and solids.

Acoustic Monitoring, Gas, Liquid, or Solid, Acoustic Equation, Visoelastic Media, Stress Relaxation Time, Average Normal Stress, the Stokes-Type Wave Equation

Mamontov, E. and Berbyuk, V. (2014) A Scalar Acoustic Equation for Gases, Liquids, and Solids, Including Viscoelastic Media. Journal of Applied Mathematics and Physics, 2, 960-970. doi: 10.4236/jamp.2014.210109.