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Design and performance of very low head water turbines using a surface vorticity model algorithm Ridwan Arief Subekti; Budi Prawara; Anjar Susatyo; Ahmad Fudholi; Sastra Kusuma Wijaya; Arief Sudarmaji
International Journal of Power Electronics and Drive Systems (IJPEDS) Vol 13, No 2: June 2022
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijpeds.v13.i2.pp1140-1149

Abstract

This study explores the numerical optimization of water turbine runner profile performance using a surface vorticity model algorithm. The turbine is designed on a laboratory scale and operates at a net head of 0.09 m, 400 rpm, and a water flow rate of 0.003 m3/s. The initial design of the turbine runner was optimized to minimize losses in the hydrofoil. The optimization algorithm is coded in MATLAB software to obtain the optimal stagger angle that will be used in the water turbine design. Furthermore, design validation was performed using computational fluid dynamics analysis ANSYS CFX to determine the water turbine performance. The settings used in ANSYS CFX include the reference pressure of 1 atm, turbulence model shear stress transport, and inlet boundary conditions using total pressure and static pressure outlet boundary conditions. The computational fluid dynamics analysis reveals that by optimizing the design, the efficiency of the water turbine increases by approximately 2.6%. The surface vorticity model algorithm can be applied to optimize the design of the water turbine runner.
Viscous Damping Coefficient Measurement System Using Incremental Optical Encoder Arief Sudarmaji; Arifrahman Yustika Putra; Efta Yudiarsah
FLYWHEEL : Jurnal Teknik Mesin Untirta Volume 9, Issue 1, April 2023
Publisher : Universitas Sultan Ageng Tirtayasa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36055/fwl.v0i0.19525

Abstract

We built a viscous damping coefficient measurement system that applies the principles of underdamped harmonic oscillation within viscous liquid. The scientific novelty of this paper lies on the type of sensor used to capture the oscillation. An incremental optical encoder is chosen as a motion detector due to its ability to convert angular position as well as rotation direction into a pair of square wave signals. The harmonic oscillator system consists of a spring with the spring constant value of 82.8 N/m, a 1.50 kg cylindrical mass and a 95.0 g prolate ellipsoidal mass. The data acquisition system converts the encoder output pulses into counts which represent the displacements of the oscillating mass under viscous liquid. We used a Proportional Integral Derivative (PID) temperature control system to maintain the sample temperature at a constant value. Experimental data suggests that the air resistance and the total friction of the mechanical components give good contribution to the damping effect of the mass’ harmonic oscillation. The repeatability test of the viscous damping coefficient measurement resulted 1.26975744 % of relative standard deviation