Final Report Summary - COPA-GT (Coupled Parallel Simulation of Gas Turbines)
The COPA-GT project, coordinated by CERFACS and funded between 2012 and 2015 under the FP7 Marie Curie-ITN programme, has been structured to provide training of a multidisciplinary and inter-sectorial nature for young research fellows in Europe in the field of propulsion and power generation systems. Indeed, the need to reduce our fuel consumption and to optimize the combustion of fossil fuels is widely accepted in the field of sustainable development and climate change. Gas turbines are widely used to produce energy by combustion, and the development of more efficient and ‘green’ turbines becomes increasingly crucial. Such a gas turbine is characterized by several physical phenomena such as heat transfer, thermal behaviour of the solid parts, acoustics, noise generation or mechanical vibration. Gas turbine optimization is therefore a complex multi-physics, multi-component problem, which requires significant engineering experience and often expensive experimental and numerical test campaigns.
Developing numerical tools and methodologies to simulate the entire GT with all physical effects was a new challenge and the overall scientific objective of COPAGT, as illustrated in the figure below, was an attempt to bring numerical simulation closer to reality and to minimize the experimental efforts. Such coupled simulations represent one of the most demanding challenges for High Performance Computing (HPC).
Significant part of the scientific work has focused on the application of developed tools to real gas turbine engines. The primary objective was to provide advanced simulations of coupled components problems covering combustor / turbine, compressor / combustor and gas / liquid / solid thermal interactions. In course of the project partners collectively produced solutions to address real problems either through the use of shared software tools or coupling algorithms. Out of these collaborations, multiple applications were made available to the combustion community pointing the need to treat component interaction early on in the design phase of real engines.
A particular work package was dedicated to the coupling of CFD tools with heat transfer computations (CHT) and simulation requirements for combustion chambers. This research has led to novel insights into coupling instabilities, which now can be accurately predicted and hence avoided. CHT simulations of turbine blades connected to the combustion chamber have been conducted at partner Turbomeca, allowing identifying the influence of hot-spots on the temperature inside the solid blades, and revealing the potential dangers of modern lean-burn combustors. The thermo-acoustic behavior of can-annular gas turbine combustor systems has been analyzed at Siemens. A moving-mesh combustor model has been developed to allow for more accurate simulations including the moving turbine blades. Finally, atomization, evaporation and combustion models have been developed and validated against experimental data.
The dedicated work package on the description and analysis of different coupling strategies for multi-physics applications for gas turbines has been very active. All partners have developed and tested several coupling strategies. In particular, the strategy which has been commonly employed, was the coupling based on the exchange of Dirichlet-Neumann boundary conditions. Individual aspects of the coupling strategies can be found in the technical reports.
Regarding training & mobility activities, several ESR and ER fellows were formed and had the opportunity to work intensely not only on fundamental research problems but also in close link with industry. Several of them were hired by the industrial partners at the end of their training period through COPA-GT. The project web site, http://copagt.cerfacs.fr , will remain fully accessible beyond project termination.