Trapezoidal Weir Guide Vanes Conduct the Discharge Coefficient

Important labyrinth spillway of hydraulic structures to regulate and control the flow of water in canals, rivers and reservoirs dams are considered important. Labyrinth spillway by increasing the length of the spillway crest on the slope in a given headwater they will increase the current carrying capacity. The main objective of this study is the effect of different screen angle and height of directorial on discharge coefficient on trapezoid labyrinth spillway. For this purpose, after doing dimensional analysis by Buckingham method, the relationship resulted in the discharge coefficient (Cd) function of parameters such as the angle of the blades (θ), blades height (hb) and hydraulic load ratio was to spillway height (H0⁄P). The present research experiments have been done on a flume was of 12m, a width of 30cm and a height of 50cm. the results showed that the rise directorial blade angle for a constant and fixed height (7/5, 15, 22/5) led to the discharge coefficient for all the hydraulic load decreases, the reason for this increase confusion and turbulence in the flow lines over spillway and followed by abnormality in bleeding time is different for hydraulic loads ratio the highest spillway discharge coefficient is an spillway with 30 degree angle blades. The results showed that the increasing discharge coefficient of a spillway control to a spillway was a height of 7/5 and 15cm blade respectively. In other words, the ultimate increase of a discharge