Abstract: The characteristics of drag and lift forces on a circular cylinder model near a wavy boundary have been experimentally investigated in a water tunnel, tn the range of the Reynolds numbers, based on the diameter of cylinder model, from 104 to 1.9104, the drag, lift force on the cylinder and lift force frequencies have been measured at the wave crest and trough and various distances from the wavy boundary. Flow visualization experiments revealed the wake structure varying with the gap-to-diameter ratio (G/D) ...