Kaplan turbine CFD Simulation, ANSYS Fluent Training

Kaplan turbine CFD Simulation by ANSYS Fluent Training

This simulation is about the Kaplan turbine via ANSYS Fluent software.

Turbomachines, also known as fluid machines, are widely used in the industry. Therefore, studying their behavior in a fluid environment is very important. Turbomachines are divided into two general categories.

The first group works by taking energy and transferring it to the fluid, and the second group, by doing work and taking energy from the fluid, transfers it to the system in various forms.

The first group’s examples are fans and compressors, and wind and water turbines can be mentioned as the second category. Kaplan turbines fall into the second category. Inward Flow Reactive Turbines are one of the most popular turbines used in the industry, using the concepts of Axial and Radial flows.

The inlet is a tube that rotates around the guide valves. The water enters the runner tangentially through the guide valves and becomes spiral by the runner propeller blades, which eventually causes the runner to rotate.

This project investigates the water flow passing over the Kaplan turbine. The Kaplan turbine rotates at 3300 rpm. The geometry of the present model is drawn by Design Modeler software.

The model is then meshed by ANSYS Meshing software. The model mesh is unstructured, and 919824 cells have been created.

Methodology

In this simulation, the MRF (Frame Motion) option has been activated to model the rotation of the turbine. In this simulation, the MRF (Frame Motion) option has been activated to model the rotation of the turbine.

It is assumed that the fluid around the turbine blades is rotating instead of the turbine blades. The rotational velocity of this fluid is equal to the rotational velocity of the turbine. To do this, the MRF tool is used in Cell Zone Conditions.

Conclusion

After simulation, 2D and 3D contours of pressure, velocity, and surface pressure are obtained. Also, the velocity vector of fluid around the turbine is obtained. Velocity vectors show the rotational motion of the fluid around the turbine blades.

As seen in the pressure contour for the turbine’s surface, some sections on the turbine blades are exposed to decreased pressure. These parts can potentially be where the cavitation can occur and should be studied and examined more carefully.