Validity of one-dimensional models of collapsible tube flow based on three-dimensional calculation of tube deformation

This paper deals with two one-dimensional models for a collapsible tube based on the three dimensional calculation of the tube deformation with the finite element method. The complex deformation of the tube due to an external pressure was calculated for the condition of no flow though the tube. The numerical results for the tube deformation agree with the experimental measurement. In the present one-dimensional models the collapsible tube is modeled as a simple membrane or a beam. Comparing the three-dimensional computational result with those of the one dimensional membrane model and the beam model, the equivalent tension and the equivalent beam thickness were derived. By comparing the numerical and the experimental results, the validity of one dimensional models was investigated for both the steady flow and the unsteady flow with a self-excited oscillation. It was shown that both of one-dimensional models qualitatively represent the characteristics of the collapsible tube.