V.T.Grinchenko, G.L.Komissarova Properties of normal waves of a composite elastic-fluid waveguide placed to a fluid |
Acoustic bulletin, Vol. 9 ¹ 4, (2006) |
| The paper deals with studying the peculiarities of axisymmetric wave motions in a fluid-filled elastic cylinder surrounded with a fluid environment. Radiation to the environment establishes the special wave attenuation mechanism: a radiation damping. The technique is proposed for determining the real and complex roots of the dispersion equation for the considered waveguide type. The differences of the kinematic and energy characteristics of the normal waves for the cases of the stiff and compliant cylinders are analyzed and discussed. The effect of the radiation damping on the characteristics of evanescent waves propagating in opposite directions. The study considers the properties of non-attenuating surface waves (of the Stoneley wave type) that exist at arbitrary frequency values and any ratios of the cylinder material and fluid physical properties. The principal feature of the waveguide with the compliant cylinder is the existence in the high-frequency range of the system of normal waves not subjected to the radiation damping, which phase velocities tend to shear wave velocity in the cylinder material. |
|
KEY WORDS: elastic-fluid waveguide, the radiation damping, wave of the Stoneley type, compliant and stiff materials, no-attenuated surface waves |
| TEXT LANGUAGE: Russian |