Theoretical approximations to analyse the onset of self-excited oscillations in flow through collapsible tubes

In this study, flow through collapsible tubes is analysed theoretically for the case of the onset of collapse which induces self-excited oscillations. The basic tools in the theoretical calculations are the linear stability theory and the tube law. The experimental data in the form of measured oscillation frequency at the onset of collapse of an elastic tube is supplied as a base input parameter for the theoretical approximations. The calculations offer a possibility for estimating the unmeasured parameters such as critical oscillation speed, speed index, and tube cross-sectional area at the onset of collapse. It was seen by referring to the obtained results that theoretical predictions agreed with the experimental measurements.