Pelton Turbine: Acoustic Analysis

Pelton Turbine, Acoustic Analysis, ANSYS Fluent CFD Simulation

Description

This project simulates a Pelton turbine under acoustic analysis using ANSYS Fluent. A Pelton turbine is a hydraulic turbine that harnesses the energy of pressurized water to rotate a wheel fitted with cup-shaped blades, converting that energy into mechanical power.

Sound generation in mechanical equipment is generally considered an undesirable byproduct, arising from the propagation of sound waves near surfaces. Acoustic analysis provides a way to investigate sound sources and noise propagation power across various systems, including rotating equipment and turbomachinery such as this turbine.

The 3D geometry was modeled in Design Modeler, representing the interior of a closed chamber housing the Pelton turbine. The domain was meshed in ANSYS Meshing, generating approximately 4,136,000 cells.

Methodology

Acoustic behavior was captured using the Broadband Noise Sources method, which estimates noise generation and predicts acoustic power levels emanating from the identified sound sources. Turbine rotation was represented using the Moving Reference Frame (MRF) approach, applying rotational motion to the fluid region surrounding the turbine body; since the simulation was run under steady-state conditions, this rotation was implemented through the Frame Motion tool at a specified rotational speed.

Conclusion

The results capture both the fluid flow behavior and the resulting acoustic characteristics. The acoustic power level contour on the turbine body — representing the sound power, in decibels, generated as the surface interacts with the fluid — shows the highest acoustic power levels concentrated on the turbine blades themselves.

This pattern aligns closely with the turbulent intensity contour, which shows the same trend: wherever turbulent intensity is higher, acoustic power level rises correspondingly. Pressure and velocity contours around the turbine body further reinforce this relationship, with the highest pressure and velocity values also concentrated near the turbine surface — consistent with the turbine body being the dominant source of sound generation in this system.

Together, these consistent, physically coherent patterns across the acoustic, turbulence, and flow results confirm that the simulation was performed correctly and accurately captures the turbine's acoustic behavior.