Abstract
A modal impedance matrix is formulated for an infinite cylindrical source undergoing axisymmetric oscillations in a thermoviscous acoustic medium. The formulation utilizes the governing equations of Hasheminejad and Alibakhshi and the analysis method of Hasheminejad and Geers. A matrix based method is used to generate the impedance curves. At first governing equations of the acoustic fields in the thermoviscous fluid are manipulated to yield the well-known Helmholtz equations and corresponding wave numbers. Equations of radial and meridional velocities and the excess temperature are also derived. In addition, the classical relations for radial and meridional stresses and the heat flux are employed as potential based equations. Velocities and the excess temperature as well as the stresses and the heat flux are expressed as Hankel series with unknown coefficients at the surface of the source. Eventually the modal impedances for three first modes are calculated and plotted as a function of distance from the source surface. Numerical results for immersion in glycerol and olive oil are obtained as examples. Considering the thermoviscous effects in cylindrical coordinates can be regarded as the main contribution of the present work to the previous ones.
Original language | English |
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Title of host publication | Proceedings of 20th Annual International Conference on Mechanical Engineering-ISME2012 |
Number of pages | 4 |
Publication date | 2012 |
Publication status | Published - 2012 |
Externally published | Yes |
Event | 20th Annual International Conference on Mechanical Engineering - Shiraz University, Shiraz, Iran, Islamic Republic of Duration: 16 May 2012 → 18 May 2012 Conference number: 20 |
Conference
Conference | 20th Annual International Conference on Mechanical Engineering |
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Number | 20 |
Location | Shiraz University |
Country/Territory | Iran, Islamic Republic of |
City | Shiraz |
Period | 16/05/2012 → 18/05/2012 |
Keywords
- Thermoviscous fluid
- Acoustic impedance
- Cylindrical source