Original scientific paper
An Experimental Analysis of Airflow in Various Collapsible Tubes at the Onset of Self-Excited Oscillations
Vedat ORUÇ
orcid.org/0000-0001-9055-1508
; Department of Mechanical Engineering, Dicle University,Diyarbakır, Turkey
Melda ÖZDINÇ ÇARPINLIOĞLU
; Department of Mechanical Engineering, University of Gaziantep, Gaziantep, Turkey
Abstract
The experimental results of airflow through some collapsible tubes are analysed in this paper for the case of onset of self-excited oscillations without so much focusing on the mechanisms triggering the oscillations. The basic experimental measurements are the pressure values at both of upstream and downstream ends of the collapsible tube as well as velocity at downstream of the tube by means of a hot wire anemometer. The obtained results correspond to the instant at which oscillations appear. It has been established that the flow is substantially chaotic during the vigorous oscillations. The experimental data at the onset of self-excited oscillations was evaluated subsequently to obtain some non-dimensional parameters based on oscillating flow velocity, frequency, pressure drop through the collapsible tube and downstream transmural pressure. The variations of these parameters with some terms including all geometrical and mechanical characteristics of the collapsible tubes are presented. The diversity of experimental variables such as collapsible tube type, tube-wall thickness, tube length and flow rate which are varied in the investigation should be useful on account of having a general information about collapsible tube flow researches. It has been recognized that all of these variables considerably affected the behaviour (frequency, velocity, upstream and downstream pressure) of oscillations and conditions of their emergence. It can thereby be suggested that the specifications of the tube should be carefully considered in the collapsible tube flow investigations.
Keywords
Collapsible tube flow; Fluid-structure interaction; Self-excited oscillations onset; Wall inertia
Hrčak ID:
78435
URI
Publication date:
30.6.2011.
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