Develop numerical models that predict the reduction in supersaturation in different types of hydropower facilities and under different saturation levels

In Work package 2 researchers aim to make the theoretical models in WP-1easily available and attractive to the relevant industry.  As part of WP-1, a theoretical model for the prediction of supersaturation and degassing with ultrasound technology will be developed.

The next question of interest is then: How can this model become easily available and attractive to the relevant industry?

Our answer to that question is to reformulate and implement the model into computational fluid dynamics (CFD) software that much of the relevant industry uses already today. The threshold for taking the models in use will thus be small; the concept of numerical simulations is often already present and then there is no larger economic cost associated as both software, hardware and staff are already in place. In addition, the partners involved in this project are tightly connected with major companies in the relevant field which makes marketing and distribution of the model simple to facilitate.

The purpose of this WP is the numerical implementation of the theoretical model developed as part of WP-1. Implementation will be done as an add-on module to commercial codes used in the relevant industry sector. Focus will be on model robustness, speed, and usability, and the aim is that the module should be easy to use for a typical engineer in the relevant field without any specific training.

The implemented model will provide a spatial and temporal distribution of the degree of supersaturation as well as degassing given the actual configuration of the hydropower components. It will also allow engineers to investigate the effect of modifying design of equipment and changing flow conditions. Provided that the underlying CFD code has support for optimization, the model will be able to suggest optimal design with respect to saturation and degassing. The code will be fully parallelized and ready to use on commercial high-performance computing (HPC) platforms.

The implementation will be done in several steps. The initial step will be to determine if the proposed model can be implemented as a variant of existing models. Modifying existing models has several advantages compared to implementing “from scratch”, as many typical implementation issues have already been resolved. A first draft of the model will then be implemented and briefly validated. Robustness and performance will be improved to make the model more usable and tractable for parametric studies and/or optimization. The final version of the implementation will also be accompanied by a simpler graphical user interface to facilitate user interaction.

The content of dissolved gasses in production water downstream of a hydropower turbine, and after ultrasonic treatment, eventually depends on the residence time in the river reach. Consequently, a 2D free surface flow model approach will be applied to the downstream river reach from the tailrace by use of the free HEC-RAS 5.0 software. The results from such a model will support the assessment of toxicity for aquatic species downstream of the power plant and assist the dimensioning of sufficient ultrasonic exposure.





Love Håkansson
Senior Technical Consultant, EDR Medeso

Leader work package 2