SPATIAL-MAPPING OF VELOCITY POWER SPECTRA IN TAYLOR-COUETTE FLOW USING ULTRAFAST NMR IMAGING

Ultrafast NMR imaging was used to clarify spatiotemporal structures of wavy Taylor-Couette flow. NMR images designed to give a radial veloci ty distribution in a cross-sectional plane containing the rotation axi s were successively taken at 200 ms time intervals. Distributions of v elocity power-spectral components were obtained by temporal Fourier tr ansform of the sequential velocity images. The obtained spectral maps clearly visualized the spatial structures of the wavy components in th e cross-sectional plane.