Chairholders
Profile
Stéphane Étienne
Polytechnique Montréal
Chair title
NSERC/General Electric Industrial Research Chair in Two-Phase Flow
Chair program
Industrial Research Chairs program
Role
Associate Chair since 2017
Summary
The research program of the NSERC/General Electric Industrial Research Chair in Two-Phase Flow deals with the injection of air in hydraulic turbines used for generating electricity. For several decades, General Electric has been injecting air into hydroelectric turbines by means of a valve in order to limit acoustic and mechanical vibrations in the equipment. This measure for attenuating vibrations induced by two-phase flow becomes increasingly indispensable when intermittent energy sources are connected to the grid and the hydraulic turbines are operated at variable settings. Furthermore, General Electric designs and builds turbines equipped with aeration devices that can reoxygenate water after it has passed through them, to satisfy environmental and regulatory requirements. The establishment of the Industrial Research Chair gives General Electric the opportunity to strengthen its ties with Quebec universities and take advantage of the infrastructure and expertise that Polytechnique Montréal has to offer for research on two-phase flow. The Chair will thus make it possible to develop a set of technologies and new knowledge with a view toward optimizing and better predicting the performance of hydroelectric systems and aerating and oxygenating water after it has passed through turbines, so as to minimize their environmental impact. The Chair will also provide more in-depth fundamental knowledge about air-water two-phase flows. Thus the Chair’s main priority will be to study the characteristics of two-phase flow, both because there is a real need for experimental data and because the current two-phase numerical codes are unreliable, due to the lack of a model specific to this type of flow.
The Chairholder, Stéphane Étienne, is a specialist in numerical modelling and experimental measurement of flows for free-surface two-phase flow applications and in fluid/structure interactions. Dr. Étienne’s research team has acquired expertise and built test sections designed specifically for two-phase flows. The numerical simulations and tests conducted under his supervision have yielded significant advances in the understanding of two-phase flows and their effects on structures.
The research carried out will address the partner’s needs as well as the incumbent’s research interests and will deal with two-phase flows. The Chair’s research program will yield benefits both experimentally and numerically. Experimentally, measuring tools and equipment suitable for two-phase flows will be developed and will be used to establish a database that can provide a better understanding of two-phase flows and to validate the numerical simulation models. At present, there are very few experimental data on high-speed, low-pressure air-water two-phase flows. Also, because there is no similarity law for turbines equipped with aeration devices, the primary objective of the testing will be to establish similarity laws that can be used as the basis of a methodology for transposing results obtained with a scale model to a full-size prototype that can be commercialized. Numerically, an understanding of the small-scale phenomena will make it possible to complete the two-phase flow simulation models. Specifically, the current models do not represent the physics of two-phase flows correctly. The proposed research aims to pose the problem of modelling two-phase flows correctly. This problem is not posed correctly at present, because the averaged equations are incomplete. Thus, the Chair’s program will make it possible to correctly establish numerical methods and formulas suitable for two-phase flows.
Partner
- General Electric Company
Contact information
Polytechnique Montréal
Website:
https://www.polymtl.ca/
