A test rig for the investigation of airflow through collapsible tubes

In this paper, an experimental set-up for investigating airflow through collapsible tubes has been described in detail. The test rig is basically composed of an airtight chamber socalled 'Starling resistor', which includes a length of collapsible tube attached to rigid tubes at its ends, a compressor supplying steady airflow, and measuring devices. The self-excited oscillations that develop due to strong fluid-pipe interaction cause the flow to be time dependent. A data acquisition system is utilized to obtain the measurements. Therefore, it is possible to measure simultaneously the time-dependent parameters, which are upstream and downstream pressures, velocity downstream of the collapsible tube. It has been verified by referring to the experimental results that the calibration of the whole system is satisfied and the measuring instruments give sensible output in combination with the data acquisition system. The presented test rig should be useful in point of view for testing possibility of airflow in soft elastic tubes.