Development of Recommended Practice and Toolkit for accurate load prediction on high head Francis turbines

The underlying idea for value creation is to develop a solution for accurate and fast simulations of high head Francis turbines. The project will deliver two ready to use innovations:

1. A Recommended Practice for Fluid-Structure Interaction (FSI) simulations on high head Francis turbines. This Recommended Practice will describe, in detail, modeling techniques. Valid assumptions to achieve reliable and accurate results will be presented. The ambition is that this document will be the industry standard in future simulations on high head Francis turbines.

2. A software Toolkit supporting the developed workflow. Mathematical models, that could be implemented to reduce simulation time, exists. The pre- and post-processing is per today tedious and gives room for human error. The Toolkit will be a product packaged in a user-friendly environment to secure reduced simulation time with respect to both CPU demand and human interaction.

The average age of a Norwegian hydro power plant is 45 years, and many show sign of fatigue and needs to be maintained or refurbished. Some newly refurbished high head power plants have experienced failures after having new and modern Francis runners installed. The main problem is that the turbine runner develop cracks in the blades due to cyclic loads. The necessity of being able to calculate these loads is highlighted by the industry as a prerequisite to achieve improved turbine designs and thereby reliable operation in the future. The Recommended Practice along with the Toolkit will be a vital and valuable innovation to meet the future requirements.

The central R&D Challenges addressed in this project is:

1. Accurate fluid flow prediction

2. Prediction of natural frequencies of the turbine runner

3. Correct handling of Fluid Structure Interaction for high head Francis turbines

4. Robustness and applicability of the developed simulation process

5. Reduction of simulation time

6. Workflow improvements

The primary objective is to develop a simulation process for accurate load prediction of high head Francis turbines.

Secondary objectives:

1. Determine valid assumptions for accurate prediction of natural frequencies and loads on high head Francis turbines.

2. Reduce simulation time by developing, and implementing, improved modelling techniques without reducing accuracy

3. Improve pre- and post-processing workflow for FSI simulations on high head Francis turbines to reduce risk of human error

4. Establish a Recommended Practice as the industry standard for FSI simulations on high head Francis turbines.

In addition to this, the companies below has supported the project with an in-kind contribution: