Abstract
The flow resistance of flat plates with hydrophilic gel wall in water tunnel were measured. A test hydrophilic gel was produced by using agar, which was prepared with concentration of 0.75, 1.0, and 3.0%. Experiments were performed in the range of flow velocity U of 0.04 < U < 0.3 m/s. Drag reduction was obtained for all values of the concentration. The maximum drag reduction was approximately 9.7%. Throughout the measurement range, the larger drag reduction was obtained with the smaller agar concentration. As the flow velocity increased, the drag reduction decreased.
