Abstract
The pressure loss and flow rate in a rectangular channel with a hydrophilic gel wall were measured. A test hydrophilic gel was produced by using agar, which was prepared with swelling degree S values of 33, 66, and 133. Experiments were performed in the range of Reynolds number of 30 < Re < 200. Drag reduction was obtained for all values of the swelling degree. The maximum drag reduction was approximately 28.4% at S = 133. As the swelling degree increased, the drag reduction also increased. However, as the Reynolds number increased, the drag reduction decreased. Furthermore, for this experimental condition, the flow (shear stress and pressure) did not greatly affect the deformation of the gel wall and the change in the channel height.
