An investigation of adiabatic spiral vortex flow by means of cross-wire probes

Flow transitions occurring with increase in the Taylor number in an annular gap of radius ratio 0.8, having an imposed axial flow of air of Reynolds number 500 have been studies using the output from a cross-wire probe in a complex digital analysis. Cross and phase spectra, together with auto and cross correlograms, are presented for four Taylor numbers from 10 620 to 12.2 × 10⁶, covering the onset of vortex flow, chaotic flow and turbulent vortex flow. As the Taylor number increases, there is little alteration in the spiral vortex flow in the axial and tangential directions, which oscillates in phase in these two directions. The tangential velocity gradient was seen to become increasingly dominant, with increase in the Taylor number