nozzle location effects on scour due to wall jets

The result of 40 experiments in the field of scouring by three dimensional wall jets were conducted in this paper. Experiments were carried out at the different values of densimetric Froude number that ranges was 3.9 to 6.6, a range of tailwater condition was 4 to 15 times the dimensions of the jet and for the three same cross-section nozzle with different dimensionless axial distance from the channel wall in ranges of 0.5 to 17.3. At first in this paper the scour mechanism caused by the wall jets was described. The effect of jet distance to the channel side wall was also investigated. The results of the paper verified with the previous studies. Laboratory observations and results show that the nozzle distance from the channel side wall caused the jet deviation towards the near wall and asymmetric in flow regimes. The factors has significant influence on scour due to jets as the maximum scour depth increased by decreasing of the distance of the nozzle to the side wall. Also in most cases the scour longitudinal parameters decreases by increasing the distance of the nozzle to the side wall. It was found that tailwater depth has an influence on scour longitudinal parameters. According to the results it can be note that the effect of jet location on scour is significant and can be considered as an effective parameter in scour cause by wall jets.