Francis Turbine Acoustics Analysis, ANSYS Fluent CFD Simulation Training

Description

Francis Turbine Acoustics Analysis, ANSYS Fluent CFD Simulation Training

description

Francis turbines are one of the types of water turbines that can use kinetic and potential energy for power generation at the same time due to the location of their blades.

In this type of turbine, water flows into the spiral chamber because, due to the blades’ circular structure, the flow of fluid colliding with the blades must be rotational to improve the system’s operational efficiency. The water flow is then transferred to the turbine runner blades with a specific flow rate, and as a result, the desired work is produced by rotating these blades by the water flow.

Finally, the outflow of water from the turbine runner blades will be axial. In the present simulation, a flow of water with a mass flow rate of 1.996 m/s enters the turbine’s inner chamber with a rotational speed of 158 rpm for the blades.

The geometry is designed using Design Modeler software. In the design of the present model, two main parts have been considered, which include fixed walls that have fixed vanes with fixed angles and moving walls that have rotating vanes.

The model meshing has been done using ANSYS Meshing software, and the mesh type is unstructured. The element number is 4,914,404. Also, the mesh quality is considered finer in the areas close to the blades.

Methodology

Frame motion (MRF) defines the blades’ rotation inside the chamber and creates the resulting rotational flow around the blades. It is assumed that the area of water flow around the blades has a rotational motion relative to the blades, While the rotating blades have a rotational speed of zero relative to this rotating area.

We use the VOF Multi-Phase Model to define water liquid and water vapor. The Broadband Noise Sources model is used to define the acoustic model.

Conclusion

Since we have investigated the issue of the turbomachine in this case already, this acoustic review continues on the same settings.

Observations show that the rotors have a greater share of the components that create sound and show more acoustic power in the related contour. Contour linear Euler’s equations show how fast the sound propagates in the space between the rotor and the stator.