INFLUENCE OF QUANTIZED VORTEX LINES ON THE STABILITY OF TAYLOR-COUETTE FLOW IN HE-II

Taylor-Couette flow between two concentric cylinders with rotating inn er cylinder and fixed outer cylinder has been investigated in the temp erature range from 1.5 K to 2.1 K. The formation of quantized vortex l ines in the gap between the cylinder has been measured by analyzing th e amplitude of azimuthal second-sound resonances. The damping of these resonances as a function of the rotational rate of the linear cylinde r shows discontinuities at certain critical angular velocities which c an be identified with the appearance of the quantized vortex lines and with the onset of the Taylor instability. The obtained results show t hat the presence of the quantized vortex lines leads to an additional stabilization of the flow field which is in agreement with recent theo retical results. The visualization of the local flow field was achieve d using hollow glass spheres of appropriate average density. This allo wed the observation of the structure of the turbulent Taylor vortices at high Reynolds numbers.