ANALYSIS OF FLOW IN A 2-DIMENSIONAL COLLAPSIBLE CHANNEL USING UNIVERSAL TUBE LAW

This paper presents an extension of the previous analyses on the collapsible tube-flow problem using a simplified model based on a two-dimensional channel conveying a one-dimensional flow. The main objective of the paper is to exploit the static and dynamic behavior of the model, by comparing with available experimental data and examining the accuracy of calculated results obtained for different numerical resolutions. The main revision from the previous analyses is the incorporation of a universal ''tube'' law that is valid for a wide range of positive and negative transmural pressure. Most of the numerical results agree qualitatively with the experimental observations. Self-excited high-frequency oscillation with very smalt amplitude of the membrane wall is, however, predicted to occur in a flow range where the slope of the pressure drop curve is positive. If is seen that the high-frequency oscillation is associated with the motion of the separation point of the flow.