EXPERIMENTAL STUDY OF LABYRINTH WEIR

Abstract

Labyrinth weir is an innovation in the field of construction of weirs. The different studies have presented their superiority in terms of flow regulation and increasing flow capacity, but the complex geometries the labyrinth brings is a problematic matter for construction. So, we wish to be sure that after such hard work in the construction, we must get the maximum efficiency from the structure built. There are many shapes available for labyrinth weir but most common shapes used are rectangular, triangular and trapezoidal. So, in this study these three shapes are used and their efficiency is compared by comparing their respective coefficient of discharges. Their inter dependence over the crest heights and their normal or inverted placements is also taken care of in this study. The various methods that can be used are discussed in methodology and the method used in this study is given by Tullis and for the applicability of the method the ratio of height of water over weir to the crest height (Ht/P) is kept between 0.1 to 0.3 and the bed level is kept horizontal. The experiments are conducted on the 8m rectangular flume available in the DTU hydraulics laboratory. The results are presented in tabular as well as graphical representations. The results suggested that the trapezoidal labyrinth weir can provide greater efficiency in comparison to its counterparts, and the same was hinted at in the literature review also so this also consolidates the experimental results.