Fig. 1: Experimental Set-up.
From: Elastic orbital angular momentum transfer from an elastic pipe to a fluid
a Elastic Spiral Phase Pipe: L = 900 mm, d1 = 40 mm, d2 = 60 mm, hs = 63 mm, h0 = 95 mm, p1 = 12 mm and the thickness at the spiral region, ts = 4 mm (shown in zoom, the spiral region has been made partially transparent). Also shown is a view of the capped end with piezo disk, of diameter 35 mm, and attaching screws. b Acoustic Measurement Centre: Schematic of close-up of the submerged end of the pipe showing orientation of the hydrophone. The measurement plane is approximately 20 mm below the end of the pipe, intersecting the detector at its `acoustic centre'. Shown too is an example experimental profile after frequency domain analysis. c Water tank and xyz scanning stage. d Close-up of suspended pipe and scanning arm.
