The onset of self-excited oscillations in airways and blood vessels is a common phenomenon in the human body, connected to both normal and pathological conditions. A recent experimental investigation has shown that the onset of self-excited oscillations happens for values of the intramural pressure close to the contact critical pressure. The goal of this work is to analyse the dependence of the contact critical pressure on the vessel’s geometric parameters. The methodology is based on the implementation of an experimentally validated computational model of a collapsible tube. The results confirm the correlation between the contact critical pressure and the onset of self-excited oscillations in collapsible tubes. Moreover, a set of general equations to compute the contact critical pressure and the corresponding areas of collapsible tubes with arbitrary geometries has been derived.

气道和血管中自激振荡的发生是人体的常见现象，与正常和病理状况有关。最近的一项实验研究表明，自激振荡的发生发生在壁内压力接近接触临界压力的情况下。这项工作的目标是分析接触临界压力对容器几何参数的依赖性。该方法基于经过实验验证的可伸缩管计算模型的实施。结果证实了接触临界压力与伸缩管中自激振荡的发生之间的相关性。此外，还导出了一组计算接触临界压力和任意几何形状的溃缩管的相应面积的通用方程。