A.O.Borisyuk Experimental study of the wall pressure fluctuations in elastic pipe behind a local axisymmetric narrowing |
Acoustic bulletin, Vol. 6 ¹ 4, (2003) |
| Wall pressure fluctuations pt in an elastic pipe behind a local axisymmetric narrowing are studied. Sharp increase in the pressure pt in a finite region immediately downstream the narrowing and the presence of a pronounced pressure maximum upstream the point of jet re-attachment were found. The study of the wall pressure power spectrum, P(f), has revealed the low-frequency maxima in it. The maxima were found to be determined by the appropriate large-scale vortex structures in the regions of separated and re-attached flow, and their frequencies were close to the characteristic frequencies of the vortices formation. Comparative analysis of the data for rigid-walled and elastic pipes shows that the wall elasticity causes the changes in the flow structure and the corresponding redistribution of the flow energy among the eddies. This results in the increase of wall pressure fluctuations amplitude pt and the level of the wall pressure power spectrum, P(f), at low frequencies, as well as appearance of new frequency components in this domain. |
|
KEY WORDS: eddy, wall pressure fluctuations, elastic pipe, local narrowing, frequency spectrum, redistribution of the flow energy |
| TEXT LANGUAGE: Ukrainian |