Influence of flow regimes on particle capture by hair-covered surfaces*

Aquatic organisms rely on hair-covered surfaces to capture molecules and particles of interest. The flow through model hair-covered surfaces has traditionally been studied in a flow channel and three regimes have been reported, with increasing fluid transport through the array: rake, deflection, and sieve. The flow regime depends on the Reynolds number of the flow, and the porosity of the array. To study particle capture, we develop an experimental set up in which the hair-covered array moves along a circular trajectory. Through a combination of experiments and numerical simulations, we characterize the influence of the flow regime on particle capture. Our results show that the capture efficiency is a function of the volume filtered and the mode of capture.