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国际流体力学研究期刊

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ISSN 打印: 2152-5102

ISSN 在线: 2152-5110

The Impact Factor measures the average number of citations received in a particular year by papers published in the journal during the two preceding years. 2017 Journal Citation Reports (Clarivate Analytics, 2018) IF: 1.1 To calculate the five year Impact Factor, citations are counted in 2017 to the previous five years and divided by the source items published in the previous five years. 2017 Journal Citation Reports (Clarivate Analytics, 2018) 5-Year IF: 1.3 The Eigenfactor score, developed by Jevin West and Carl Bergstrom at the University of Washington, is a rating of the total importance of a scientific journal. Journals are rated according to the number of incoming citations, with citations from highly ranked journals weighted to make a larger contribution to the eigenfactor than those from poorly ranked journals. Eigenfactor: 0.0002 The Journal Citation Indicator (JCI) is a single measurement of the field-normalized citation impact of journals in the Web of Science Core Collection across disciplines. The key words here are that the metric is normalized and cross-disciplinary. JCI: 0.33 SJR: 0.256 SNIP: 0.49 CiteScore™:: 2.4 H-Index: 23

Indexed in

On Generation of Tonal Sound Vibrations by Airflow in Stenotic Airways

卷 31, 册 5, 2004, pp. 456-476
DOI: 10.1615/InterJFluidMechRes.v31.i5.40
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摘要

A hypothesis about one of possible mechanisms of occurrence of wheezes (tonal sound signals) in a human bronchial tree at its pathologies is put forward. It is supposed that viscous sputum allocated in affected airways, can form aerodynamic structures of the nozzle-jet-obstacle type. A stenosis forming a high-speed jet plays the role of a nozzle in the act of breathing. The other stenosis, bifurcation of the airways or the sputum formations can play the role of an obstacle. An experimental installation was used to check the mentioned hypothesis. It included a physical model of an airway along with the equipment for recording and processing of the sound signals and for estimation of the airflow velocity. As a result of experiments it was shown that presence of the specified aerodynamic structures can provide an efficient transformation of energy of the stream in airways into energy of the sound vibrations, which spectra are very similar to those of wheezes. A number of laws, being characteristic for the considered structures, is established. The threshold values of flow velocities when the tonal sound vibrations start to arise are estimated. It is shown that the relative distance between a stenosis forming a jet and an obstacle being increased, the threshold Reynolds numbers and the threshold frequencies of the tonal signals tend to a decrease, and the threshold Strouhal numbers - to an increase.

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