A method for calculating the acoustic radiation generated by the large scale instabilities of axisymmetric jets is developed. The characteristics of the flow instabilities are obtained from the linearized, inviscid, compressible equations of motion in terms of an asymptotic expansion. This asymptotic expansion is not uniformly valid far away from the jet flow. To obtain a solution valid far away from the jet, the method of matched asymptotic expansions is used. The matching of inner and outer solutions provide two very important results. First, a new interpretation of the eigenvalue problem of classical instability theory is given. Secondly, matching provides a method for determining the slow varying wave amplitude of the instability wave allowing for a complete spatial description of the instability wave to order unity. Calculations of the instability wave characteristics, near- and far-field pressure fluctuations for an unheated, ideally expanded, moderate Reynolds number jet with jet exit Mach number of 2.1 are performed at several frequencies and for the axisymmetric and helical instabilities. The numerical results of this model are then compared with experiments and good agreement is found in both the jet flow and near-field. / Source: Dissertation Abstracts International, Volume: 42-10, Section: B, page: 4099. / Thesis (Ph.D.)--The Florida State University, 1981.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_74673 |
| Contributors | BURTON, DALE EDWARD., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 183 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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