Dataset corresponding to publication: "Effect of axially varying sandpaper roughness on bubbly drag reduction in Taylor–Couette turbulence "

This dataset contains measurement data from drag comparison experiments over rough, smooth, and partly rough walls in turbulent flows. A Taylor–Couette apparatus was used for the experiments, of which the inner cylinder was made rough by attaching sandpaper belts to it. By varying the width (indicated by <i>s/d</i>) of the sandpaper belts, and also the corresponding spacing between two belts, an axially varying pattern of a rough-smooth surface was created. The drag reducing effect of air bubbles is studied for the different surface roughness configurations.<br>See readme.txt file for more information regarding the dataset.