Author(s): V. P. Gadhe; S. R. Patnaik

Linked Author(s):

Keywords: Additional Spillway; Chute block; Dentated sill; Flow 3D CFD; Type II Stilling Basin

Abstract: Stilling basins are frequently used as energy dissipaters to protect the downstream hydraulic structures from scouring. The stilling basin uses the hydraulic jump as the hydraulic element for dissipating energy in a specific structure. A Stilling basin type of energy dissipator is mainly used for economic reasons; therefore, the Stilling Basin II type has been used on high and earth dam spillways and large canal structures. Basin II type design aims to reduce the hydraulic jump length by installing accessories, such as chute blocks and dentated sill in the stilling basin. Hirakud Dam is one of the multipurpose projects. In order to safely pass the reassessed additional flood of Hirakud dam, two additional spillways at suitable locations were proposed. One of these was proposed on the main spillway's left bank (Phase-I). Hydraulic model studies of this left bank additional spillway was carried out at CWPRS. This paper is focused on the physical and numerical model studies to assess the performance of the proposed BASIN II type energy dissipator and to finalize the design of the additional spillway on the left bank (Phase-I). Physical model study results revealed that the performance of the original spillway design with energy dissipators was unsatisfactory as the length of the stilling basin provided was insufficient to contain the hydraulic jump. Hence the modification in the length of stilling basin was suggested by the CWPRS. The physical model studies have also been carried out on the modified design and finalized the design of spillway and energy dissipator. The numerical model studies validate the simulation results with the physical model study results for the original and modified design. Numerical Model studies have been carried out on the licence copy of Flow 3D CFD software at CWPRS.

DOI: https://doi.org/10.26077/1bf0-acd4

Year: 2022