HYDRAULIC PERFORMANCE OF I-HEAD AND T-HEAD GROYNES IN SERIES

Abstract

Groynes are commonly used structures in rivers to prevent erosion of riverbanks that may occur due to the concentration of flow. They also help in changing a sharp bend into a bend with a larger radius of curvature. In addition to this, groynes are useful in promoting navigation, restoring rivers, nourishing banks, and increasing the diversity of the river's morphology and ecology. Groynes are also known as transverse dikes. They are constructed to protect the bank from which they are extended by deflecting the current away from the bank. In river training structures known as groynes are frequently employed to safeguard riverbanks from the harmful effects of flow concentration. Groynes also assists in the transformation of sharp bends into more gradual curves, making navigation easier and promoting the restoration and nourishment of riverbanks. Additionally, they have been shown to enhance morphological and ecological diversity in river ecosystems. Groynes are widely used in river training, motivating to work on unsubmerged T-Head and I-Head groynes. Restricting the horizontal movement of the river channel following a specific alignment is the main goal of river training operations. By increasing the depth of flow and deflecting the flow away from the bank along with it, different groynes are utilized as a solution for river training. The mean and turbulent flow parameters have been experimentally explored in this experimental investigation. These characteristics include depth, time-averaged three-dimensional velocity distribution one of the flow parameters, whereas other flow parameters are Reynolds stresses, turbulent kinetic energy, and bed shear stress. In the upside of the river there is recirculation region, horseshoe vortices with amplified transverse velocity and down flow with increased vertical velocity are both evident. The importance of the Head shape of the groynes with the same flow parameters, Reynolds number, and Froude number of the experimental channel can be better understood by comparing two groynes in series, i.e. I-Head groynes and T-Head groynes. The significance of series application of T-Head and I-Head groynes in actual practice is evident from the results.