(Similarity) EFFECT OF DIAGONAL FORMATION OF PLATE PERFORATIONS ON THE TYROL WEIR DISCHARGE COEFFICIENT VALUE

The purpose of this research is to find the equation of discharge coefficient (Cd) on a tyrol weir
with diagonal circle filter sieve holes. To determine the discharge coefficient (Cd) a physical model test was
conducted in laboratory by creating an open channel with a width of 40 cm and a length of 797 cm. Hole
variations were made with diagonal formations with diameters of 6, 8, 10 and 12 mm, screen slope θ = 20°–
45° and flowrate Q = 453–4 481 cm
. The physical test showed that the water flow for the diagonal holes
was about 140% more than for the screen with a straight formation of holes. The value of the discharge
coefficient (Cd) constant is directly proportional to the froude number (Fr), the slope of the filter (θ), the ratio
between the distance of the filter to the hole diameter (x/d) and inversely proportional to the specific energy
(E). The value of the discharge coefficient constant is directly proportional to the Froude number, the slope of
the filter, the ratio between the distance of the filter with the hole diameter and inversely proportional to the
specific energy. After analysis, the results obtained that the value of the discharge coefficient constant (Cd)
ranges between 0.15-2.75, then the accuracy of the model test obtained RMSE = 0.096, MAE = 0.074, NSE =
0.836.

Keywords: Tyrol weir, Diagonal Formation Screen, Circular Perforated Plate, Discharge Coefficient