Determining the Best Place of Installation for Deflector in Rubber Dams

Rubber dam body is a lying cylinder that lies in the width of channels، rivers and weir crests and is filled with water or air or a combination of both. Shape of this structure is one of the obvious features that does not change in the path of rivers or dam spillways. Rubber dams may be with or without deflectors. Deflector is a triangular or rectangular fin that is installed down the stream of the dam. The purpose of installing a deflector is separating the water from the rubber dam body and avoiding the reattachment between the water and dam body. In this study، four Physical models of rubber dams and deflectors were made at height and ratio of h/p=0. 05 in 2 triangular and rectangular shapes and 25 cm length. Experiments were carried out in three different angles (30-45-60). After all the analyses and experiments were done according to the water napes profile and their lengths، it was observed that the 45 degree is more suitable than 30 and 60 degrees. In addition، experimental data and presented equation in this study were compared with the past equations، the results of which were close، showing the validity of the experiments and equations