Measurements of small radius ratio turbulent Taylor-Couette flow

In Taylor-Couette flows, the radius ratio ($\eta = r_i/r_o$) is one of the key parameters of the system. For small $\eta$, the asymmetry of the inner and outer boundary layer becomes more important, affecting the general flow structure and boundary layer characteristics. Using high-resolution particle image velocimetry we measure flow profiles, local transport, and statistical properties of the flow for a radius ratio of 0.5 and a Reynolds number of up to $4\cdot10^4$. By measuring flow profiles at varying heights, roll structures are characterized for two different rotation ratios of the inner and outer cylinder. In addition, we systematically vary the rotation ratio and the Reynolds number. These results exemplify how curvature affects flow in strongly turbulent Taylor-Couette Flow.