Determination of slot optimal location at bank attached triangular submerged vane in the 90 degree bend

According to the conditions of any river, different methods are used to protect of erodible rivers bank. One of these methods is the use of banks protection structures such as submerged vanes. The main problem of these structures is to local scour of around the nose structure. One of the effective methods of flow pattern improvement around the structures is creating slot in structure. In this study, has been created rectangular slot (with fixed dimensions) in three different positions in bank attached triangular vane, this means that the slot is parallel to the chord in first vane, parallel to the base in second vane and parallel to the vertical side of triangular vane in third vane. The research aim is to determine the slot optimal location, with defined dimensions. Experiments were conducted in the single-vane posture and under different hydraulic conditions (clear water condition). Results showed that the first vane (slot is parallel to the chord) had the best performance to reduction of volume, Length and width of scouring. Also, the maximum scour depth in this vane was 35% and 13% less than two other vanes that slot is parallel to the base and parallel to the vertical side, respectively.