Hydraulic and Structural analysis of penstock bifurcation with and without sickle plate: Ghar Khola Hydropower Project, Nepal

Abstract

Bifurcation in the hydropower plant is necessary to separate the flow towards the two units of hydro turbines on the same powerhouse for multiple benefits. The type of bifurcation depends on the site condition, either symmetric or asymmetric. This research reports the asymmetric bifurcation condition through the novelty of numerical simulation of multiple models for structural analysis after the hydraulic analysis with and without a sickle plate. The hydraulic analysis using ANSYS CFX for head loss reported the difference in flow rate of 5 kg/s and 44 kg/s with and without using a sickle plate in the bifurcation. Furthermore, an analysis of 5 different models on ANSYS Static Structural showed bifurcation with a combination of sickle plate and only one stiffener is the ideal, which is based on equivalent stress of 120.6 MPa, a factor of safety of 2.073, and working conditions. It concluded the importance of flow and structural analysis of bifurcation for balanced power generation from double-unit turbines and is recommended as a critical unit for specific sites, such that different thicknesses of bifurcation shells can be analyzed for further optimization.

Bangladesh J. Sci. Ind. Res. 60(4), 275-286, 2025