Visualization of Taylor-Couette and spiral Poiseuille flows using a snapshot FLASH spatial tagging sequence

A new magnetic resonance imaging technique was applied to the Taylor-Couett e and spiral Poiseuille (Taylor-Couette with superposed mean axial flux) fl ows for the first time. The experimental technique is a combination of spat ial tagging methods and a snapshot FLASH imaging sequence, which allows the full-field visualization of 2-D slices of the flow field, with image acqui sition times approximately half a second. By acquiring images every few sec onds, direct visualization of flow patterns can be obtained in the form of cinematography. Tagged images of the Taylor-Couette flow were acquired in b oth the axial and transverse planes and confirmed previously reported numer ical predictions of Taylor cell size. Tagged images of the spiral Poiseuill e flows verified that the cells in this flow propagate at a higher velocity than the mean axial flow. In addition, intermittent cell formation was obs erved as the axial flow was increased. (C) 2000 Elsevier Science Inc. All r ights reserved.