Cluster of Education and Social Sciences, Open University Malaysia
This paper presents an experimental study to define the hydraulic characteristics of flow over square labyrinth weirs with semi-circle and sharp crest, by using range of experiments and compare their efficiency with conventional weirs (Suppressed rectangular weir) with same shape of crest, three different heights (p) for each one of these weirs were used ( 25,20 and 15 ) cm for each of the above cases , seven different discharge were passed. The overall tests in this study were 84. Data obtained from laboratory and according to the result parameters from the dimensional analysis of the factors affecting on the flow over the labyrinth weirs, parameters were plotted, it was found that the labyrinth weirs gave better performance efficiency when compared to conventional weirs (Suppressed rectangular weir) for their passage and capacity high discharge. Also the results show that the coefficient of discharge (Cd) with constant height of weir have a high value in low values of H/P and decrease gradually with increase this ratio , where gave the square labyrinth weirs with semi-circle the highest value of the discharge coefficient reached (2.55). In additional to shape of crest weir has great effect on (Cd) and on performance efficiency, where the labyrinth weir with semi -circular crest gave high performance from sharp crest.