The Effect of Tube Vibrations on Flow Through Tubes

This paper presents an approximate analysis and an experimental investigation of the effect of external vibration of flow in tubes. Only flow in straight tubes of uniform cross section was considered. It is shown that external vibration of the tube produces small fluctuations, it was found both by analysis and by experiment that the pressure drop in steady flow was not increased and that there was no delay in flow establishment after opening a valve. An incidental result of this investigation was the experimental finding that laminar flow in tubes at Reynolds numbers up to 15,000 was stable to all small external disturbances. This finding was applicable to both the fully developed region and the region of developing boundary layer beyond at least 60 tube diameters from the entrance.