An Exact Analytical Model for the Relationship Between Flow Resistance and Geometric Properties of Tubes Used in Semi-occluded Vocal Tract Exercises.
The purpose of this work was twofold. First, we aimed to develop an exact analytical model for tubes used in semi-occluded vocal tract exercises to gain a quantitative insight into the relationship between flow resistance and the tube's geometric parameters. The second goal was to provide an isometr...
| Publicado en: | Journal of Voice Vol. 33; no. 5; pp. 585 - 591 |
|---|---|
| Autores principales: | , , , |
| Formato: | equations & formulas research Journal Article |
| Publicado: |
Elsevier B.V.
Sep2019
|
| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=138691907&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 138691907 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 08921997 H24 jtl: Journal of Voice issn: 08921997 maglogo: N pubinfo: dt: Sep2019 vid: 33 iid: 5 pid: 467 pub: Elsevier B.V. place: New York, New York artinfo: ui: 138691907 138691907 138691907 10.1016/j.jvoice.2018.03.016 138691907 ppf: 585 ppct: 6 formats: tig: atl: An Exact Analytical Model for the Relationship Between Flow Resistance and Geometric Properties of Tubes Used in Semi-occluded Vocal Tract Exercises. aug: au: da Silva, Andrey R. Ghirardi, Ana Carolina Reiser, Matheus Rutzen Paul, Stephan affil: Laboratory of Vibration and Acoustics, Federal University of Santa Catarina, Florianópolis, Brazil sug: subj: Vocal Cords Physiology Therapeutic Exercise Isometric Exercises Resistance Training Human Medical Practice ab: The purpose of this work was twofold. First, we aimed to develop an exact analytical model for tubes used in semi-occluded vocal tract exercises to gain a quantitative insight into the relationship between flow resistance and the tube's geometric parameters. The second goal was to provide an isometric resistance chart that can be used by clinicians to indicate either the diameter or the length of a tube, so as to provide the same flow resistance of a reference tube. The theory for confined flows based on the Darcy-Weisbach equation was used to derive the analytical model, in which the friction factor was obtained by an explicit approximation with error smaller than 0.4%. The isometric resistance chart was generated with the analytical model, assuming the volume flow to be constant and equal to 0.4 L/s. The results obtained from the model agreed very well with both experimental and theoretical results from the literature, particularly for tubes longer than 6 cm and with inner diameters greater than 4.1 mm. In general, the analytical model slightly underestimates the back pressure for shorter and thinner tubes. For these cases, the maximum difference between analytical and experimental results corresponds to ≈5%. Analysis of the equation terms indicated that the flow resistance is significantly more sensitive to variations in the inner diameter than to variations on the tube's length, which agrees with experimental results found in the literature. Moreover, the effect of the mouth configuration is negligible for tubes whose length are one order of magnitude greater the the inner diameter. Nevertheless, for short tubes the mouth configuration becomes a significant parameter and can be described by the ratio between the tube's inner diameter and the effective diameter of the patient's oral cavity. The analytical model presented in this work can be applied to the entire set of tube geometries found in clinical practice and constitutes a straightforward tool for designing tubes for semi-occluded vocal tract exercises with specific therapeutic purposes or patient needs. pubtype: Academic Journal doctype: equations & formulas research Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
|---|