Pengaruh Closing Time Valve Terhadap Aliran Fluida di Dalam Penstock Pembangkit Listrik Tenaga Air (PLTA) Proyek Pembangunan Bendungan Bener

Abstract

The Bener Dam Project in Purworejo, Indonesia, aims to meet irrigation and raw
water needs while constructing a 10 MW hydropower plant. With a height of 154 to 159
meters, the dam also mitigates flood risks. This study analyses the hydropower plant's
operations, particularly the water hammer phenomenon, which can cause excessive
pressure and damage the piping system. Using transient analysis and Computational Fluid
Dynamics (CFD), the research reveals a water flow rate of 18.09 m³/s with velocities of
11.75 m/s in a 1.4-meter pipe and 16.00 m/s in a 1.2-meter pipe. Finite Element Analysis
(FEA) shows that closing the valve within 50 seconds generates a pressure of 19.350 bar,
safely below the 19.418 bar limit, with the highest Von Mises stress at 83.36 MPa in the
pipe bending area and 79.52 MPa near the valve, both within the safe limit of 176.5 MPa.
The findings confirm the hydropower plant's safe operation under the 50-second valve
closure scenario, offering crucial guidance for managing water hammer risks and ensuring
the project's long-term sustainability and efficiency.