Viscosity and thermal conduction will attenuate sound waves. For the moment just consider a monatomic gas where
Question:
Viscosity and thermal conduction will attenuate sound waves. For the moment just consider a monatomic gas where the bulk viscosity can be neglected.
(a) Consider the entropy equation (13.75), and evaluate the influence of the heat flux on the relationship between the pressure and the density perturbations.
(b) Consider the momentum equation (13.69), and include the viscous term as a perturbation.
(c) Combine these two relations in parts (a) and (b), together with the equation of mass conservation, to solve for the imaginary part of ω in the linear regime.
(d) Substitute kinetic-theory expressions for the coefficient of shear viscosity and the coefficient of thermal conductivity to obtain a simple expression for the attenuation length involving the wave’s wavelength and the atoms’ collisional mean free path.
(e) How do you think the wave attenuation will be affected if the fluid is air or is turbulent, or both?
Equations 13.69 and 13.75.
Step by Step Answer:
To address the questions lets work through each step and derive the expressions step by step Well consider a monatomic gas where bulk viscosity can be neglected Well begin with the given equations 136...View the full answer
Modern Classical Physics Optics Fluids Plasmas Elasticity Relativity And Statistical Physics
ISBN: 9780691159027
1st Edition
Authors: Kip S. Thorne, Roger D. Blandford
