Substantial drag reduction in turbulent flow using liquid-infused surfaces

Experiments are presented that demonstrate how liquid-infused surfaces can reduce turbulent drag significantly in Taylor–Couette flow. The test liquid was water, and the test surface was composed of square microscopic grooves measuring 100~x03BCm to 800~x03BCm, filled with alkane liquids with viscosities from 0. 3 to 1. 4 times that of water. We achieve drag reduction exceeding 35 %, four times higher than previously reported for liquid-infused surfaces in turbulent flow. The level of drag reduction increased with viscosity ratio, groove width, fluid area fraction and Reynolds number. The optimum groove width was given by w^+ 35.