In this study, the effect of the angle of the horizontal deviation of sharp edge, semi-circular crest weir and angled horizontally on the properties of flow over of weir. The study was based on dimensional analysis and laboratory work. In dimensional analysis, the following parameters were found to effect the flow over the weir; the factor of discharge ratio (Q/ g H2.5), the factor of the flow depth to the weir radius (H/R), the ratio of the flow depth to the height of weir (H/P) and the coefficient of tangent of the horizontal angle of deviation of weir from the normal line on the flow (tanα). Four value of radius of weir crest were chosen (R=5cm, 10cm, 15cm, 20cm) and the height of weir were changed four times (P=15cm, 20cm, 25cm, 30). The horizontal angle of models were changed three times (α = 15o, 30o, 45o) which results in a total number of samples of 48. The study showed a significant effect of the angle of deviation (α) on the coefficient of discharge ratio at the low values of the coefficient H/R while no significant effect observed at high values of this coefficient. The study also showed a clear effect of the angle of deviation (α) on the coefficient of discharge ratio at the low values of the coefficient (H/P), while there was little impact of the angle at the high values of this coefficient. An empirical equation was developed to calculate the discharge over this type of weir using the statistical program (SPSS) based on laboratory results. The results of the equation showed significant correlation with the laboratory results.
Volume 11 | 01-Special Issue
Pages: 1723-1729