Pelton Turbine, Acoustic Analysis, ANSYS Fluent CFD Simulation

Description

In this project, we perform the numerical simulation of a Pelton Turbine under Acoustic analysis in ANSYS Fluent software.

A Pelton turbine is a type of hydraulic turbine that uses the energy of water pressure to rotate a wheel with cup-shaped blades and subsequently produce the required mechanical energy.

Sound production in mechanical equipment is considered an undesirable phenomenon. This sound generation is due to the propagation of sound waves near surfaces. Using acoustic analysis, it is possible to investigate the sound sources and the noise propagation power in various systems, including rotating equipment and turbomachinery.

Methodology

First, we model the geometry in 3D using Design Modeler software. The computational domain is the interior of a closed chamber in which a Pelton turbine is mounted. Then, we mesh the model using ANSYS Meshing software, and about 4,136,000 cells are generated. Finally, we simulate the flow around the Pelton turbine in ANSYS Fluent software.

We use the Acoustic Model to study acoustic analysis in a Pelton turbine. For this purpose, we use the Broadband Noise Sources method. This approach estimates the noise production and predicts acoustic power levels from sound sources.

We utilize the Moving Reference Frame (MRF) to define a rotation flow zone. In other words, we apply rotation to the fluid region adjacent to the turbine body. Since the run calculation is in a steady state, we use the Frame Motion tool with a specified rotational speed.

Conclusion

After the calculations, we investigate both the fluid flow behavior and the acoustic analysis.

We obtain the contour of the acoustic power level on the turbine body. The acoustic power level indicates the sound power generated in decibels by the turbine surface during the collision with the fluid. This distribution shows that the highest acoustic power level appears on the turbine blades.

Then, we obtain the contour of the turbulent intensity. This distribution is perfectly consistent with the acoustic power level distribution, so that wherever the turbulent intensity is higher, the acoustic power level increases.

Also, we obtain the contour of the pressure and velocity distribution on and near the turbine body. The highest pressure and velocity of the circulating fluid are in the vicinity of the turbine body. This confirms the sound generation from the turbine body.

So, we can conclude that our simulation has been performed correctly.