Task 3.2: Hydropower technologies

Current project

HYPERBOLE: HYdropower plants PERformance and flexiBle Operation towards Lean integration of new renewable Energies

This project aims to study the hydraulic, mechanical and electrical dynamics of several hydraulic machines configurations – Francis turbines, reversible pump-turbines – under an extended range of operations: from overload to deep part load. Upon suitable concurrence between simulations and reduced-scale physical models results, validation will take place on carefully selected physical hydropower plants properly equipped with monitoring systems. Tests on both experimental rigs and real power plants will be performed in order to validate the obtained methodological and numerical results.

Source of funding: European Commission

Research partners: Laboratory for Hydraulic Machines (LMH) at EPFL, University of Applied Sciences and Arts Western Switzerland (HES-SO), Alstom, Andritz, Voith

Duration: September 2013 to February 2017

Project website

Research objectives
High head generating units are most often featuring Pelton turbines which experience water jets at high velocities, as high as 180 ms-1 in the case of the Bieudron (VS) Pelton turbines (1’800 m Head). Therefore, if the silt content in the water is high enough, both the needles and the nozzle of the turbine injectors and, in a less extent, the runner buckets will experience severe erosion. Although extensive studies have been made for developing resistant coating to mitigate the silt erosion, there is still a need in modeling the turbulent silt motion near the wall and the corresponding solid material erosion rate. A new numerical method, the Finite Volume Particle Method (FVPM) will be developed. This method is a mesh-free arbitrary Lagrangian-Eulerian (ALE) method, which inherits many of the desirable properties of both particle methods such as smoothed particle hydrodynamics (SPH) and conventional mesh-based finite volume methods (FVM). The motion of the silt particles and the erosion of the solid wall boundary will be simulated. Metallic material constitutive laws will be implemented and compared with the available experimental results of erosion rates provided by ALSTOM Hydro.

Current project

GPU Spheros CTI Project n°17568.1

Silt erosion impedes hydropower usage which will become more critical with the observed climate changes particularly for the new glacier lakes of the Alpine region. SPHEROS software has been developed to simulate silt-laden flows in hydraulic machines, It will be enhanced with accurate physical models for erosion and new advanced high performance computing techniques. A tool fitting the industrial needs to predict and mitigate erosion of hydro generating units is targeted.

Source of funding: Commission for Technology and Innovation (CTI)

Research partners: Laboratory for Hydraulic Machines (LMH) at EPFL, Laboratory of Hydraulics, Hydrology and Glaciology (VAW) at ETH Zurich, Lucerne University of Applied Sciences and Arts (HSLU), ALSTOM Hydro

Duration: July 2015 to October 2018

Research objectives
The development of new turbines (new hydraulic, mechanical, and electrical technologies) to harvest the energy in water supply network will be performed. Optimization through numerical simulations as well as performance investigation and measurements on test rig will be carried out to assess the technologies and optimize the new turbines.

Current projects

DUO TURBO: Providing industrial and competitive family of low-CAPEX integrated plug-and-play energy recovery stations. CTI project n°17197.1

This project focuses on turning a counter rotating micro-turbine proof of concept into a range of standard energy recovery stations able to harvest energy on drinking water networks. The plug-and-play concept to be developed will require a low investment for the final customers, reaching economic feasibility with an available hydraulic power below 25 kW. A new part of the Swiss and international renewable energy potential will then be targeted and profitably exploited.

Source of funding: Commission for Technology and Innovation (CTI)

Research partners: Laboratory for Hydraulic Machines (LMH) at EPFL, University of Applied Sciences and Arts Western Switzerland (HES-SO), Telsa SA, Jacquier Luisier SA, Valélectric Farner SA

Duration: January 2015 to December 2017

Hydropower and energy efficiency in water systems

To answer to nowadays needs for sustainable energy sources that are, at the same time, economically viable and environmentally friendly, the systems must be efficient. The best efficiency is obtained when the system is designed in the way that maximizes the energy produced and minimizes the caused damage, not violating any imposed constraint. The purpose of this research is an experimental and computational investigation of energy conversion and efficiency in water systems.

Source of funding: Portuguese Foundation for Science and Technology (FCT), École Polytechnique Fédérale de Lausanne (EPFL)

Research partners: Laboratory of Hydraulic Constructions (LCH) at EPFL, University of Applied Sciences and Arts Western Switzerland (HES-SO)

Thesis sheet

Research objectives
Fatigue is a key reliability issue for the flexible service of engineering parts, in particular in changing renewable driven energy markets. The residual scatter of the number of load cycles to fatigue failure is typically rather large so that stochastic modeling plays an important role in fatigue design. Employing finite-element simulations, the University of Lugano and Siemens are working on the development of such stochastic material models for the prediction of the behavior of engineering parts under cyclic loading. To ensure optimal reliability, the shape of engineering parts can be optimized according to new material functions whose additional regularity properties enable a treatment within the mathematical framework of shape optimization. The scope of the work will be deepened within the SCCER-SoE.

Current project

Large scale simulation of pneumatic and hydraulic fracture with phased field approach

This project aims at developing a theoretical and methodological framework for fracture mechanics, which will in particular allow for the numerical simulation of large-scale problems on recent and upcoming parallel architectures. It will exploit phase-field models as novel approaches for the representation of crack interfaces. In this project, we will use modern discretization approaches such as Isogemetric analysis (IGA) and NURBS based ansatz spaces, for which we will develop efficient adaptive techniques. Moreover, for the solution of the arising (non-)linear systems, robust preconditioners based on multilevel methods will be derived and implemented. These approaches combine the flexibility of traditional refinement techniques with a patchwise view on the discretisation, thereby allowing for the design of efficient approaches on massively parallel architectures, which profit from simple and easily maintainable data structures. In addition to the new phase-field based approach for fracture, we will also extend our new framework in order to deal with contact and frictional effects along the larger interior crack interfaces.

Source of funding: Swiss National Science Foundation (SNSF)

Research partners: Institute of Computational Science at the University of Lugano, Siemens, DFG Schwerpunktprogramm 1748: Reliable Simulation Techniques in Solid Mechanics. Development of Non-standard Discretisation Methods, Mechanical and Mathematical Analysis.

Duration: June 2014 to May 2016