Experiments on the Labyrinth Packing (1st Report)

The resistance of water as it flows through co-axial cylinders and through a labyrinth formed by cutting several grooves on the surface of the inner cylinders was studied experimentally. The following results were obtained : 1) In the co-axial cylinders with very small clearance, the resistance coefficients λ can be indicated only as functions of Reynolds Number Re. That is to say, the value of λ is 48/Re which coincides with the theoretical value for laminar flow, and that for turbulent flow is 0.26 Re-0.24, where Re=vms/ν, vm is the mean velocity, and s is the clearance. 2) In a geometrically similar labyrinth packing, it is confirmed by experiments that the resistance coefficients depend only on Reynolds Number. 3) The value of λ increases with increase of clearance for both laminar and turbulent flow within the range of these experiments. 4). The va1ue of λ is independent of the groove depth for laminar flow, but for turbulent flow it becomes max. when the groove depth is about one-fourth its breadth.