Periodic Reporting for period 2 - EXPERTISE (models, EXperiments and high PERformance computing for Turbine mechanical Integrity and Structural dynamics in Europe)
Okres sprawozdawczy: 2019-03-01 do 2021-08-31
Development of incremental and disruptive technologies in the areas of Energy and Mobility will have key impacts on the world’s societies, and on safety, security and competitiveness of Europe.
Amongst those technologies, turbines will play a major role:
- recovery of shale gas depends decisively on compressors;
- modern gas supplied power plants are bridging towards the age of renewable energies;
- aero-engines are to undergo the most massive changes in their history with the advent of composite materials, gear boxes, and turbine-electric concepts separating generation of power and thrust.
A technological commonality of the upcoming challenges is the need for full model based development and computer system simulation to address the societal needs of Quality and affordability and Safety, while reducing the development time of new products.
Thus, we proposed a European contribution through the Marie Curie Integrated Training Network EXPERTISE, whose ultimate research objective is to develop advanced tools for the dynamics analysis of large-scale models of turbine components to pave the way towards the virtual testing of the entire machine (i.e. whole engine simulations).
EXPERTISE addressed some of the challenges on the way to a fully validated nonlinear dynamic model of turbo-machinery components, by bringing together world leading institutions and companies from across Europe in a multidisciplinary project with the following scientific goals:
- improving the understanding of the physics of friction contacts in order to develop, identify and validate advanced models for dynamic simulations of turbomachinery models;
- developing efficient and accurate analysis tools for the nonlinear dynamics of turbomachinery components, based on two different and complimentary approaches: Reduced Order Models (ROMs) and Domain Decomposition Methods (DDMs);
- taking advantage of High Performance Computing (HPC) with the objective of increasing the productivity of applications developers, by extracting sufficient parallelism from the application, and doing I/O in an efficient manner.
Amongst those technologies, turbines will play a major role:
- recovery of shale gas depends decisively on compressors;
- modern gas supplied power plants are bridging towards the age of renewable energies;
- aero-engines are to undergo the most massive changes in their history with the advent of composite materials, gear boxes, and turbine-electric concepts separating generation of power and thrust.
A technological commonality of the upcoming challenges is the need for full model based development and computer system simulation to address the societal needs of Quality and affordability and Safety, while reducing the development time of new products.
Thus, we proposed a European contribution through the Marie Curie Integrated Training Network EXPERTISE, whose ultimate research objective is to develop advanced tools for the dynamics analysis of large-scale models of turbine components to pave the way towards the virtual testing of the entire machine (i.e. whole engine simulations).
EXPERTISE addressed some of the challenges on the way to a fully validated nonlinear dynamic model of turbo-machinery components, by bringing together world leading institutions and companies from across Europe in a multidisciplinary project with the following scientific goals:
- improving the understanding of the physics of friction contacts in order to develop, identify and validate advanced models for dynamic simulations of turbomachinery models;
- developing efficient and accurate analysis tools for the nonlinear dynamics of turbomachinery components, based on two different and complimentary approaches: Reduced Order Models (ROMs) and Domain Decomposition Methods (DDMs);
- taking advantage of High Performance Computing (HPC) with the objective of increasing the productivity of applications developers, by extracting sufficient parallelism from the application, and doing I/O in an efficient manner.
WP1 activity focused on improving the current contact modelling techniques for nonlinear dynamic analysis to ensure accurate predictive capabilities over the lifetime of an aeroengine by:
- developing solutions to allow engineers and researchers alike to assess the position and extent of the zones of relative cyclic motion along the interface.
- developing efficient non-linear model reduction strategy and multi-scale approaches to reduce the size of the problem and enable more complex computations.
- developing and validating prediction tools to study the effect of wear on the dynamics of structures with friction contacts.
- improving the understanding of the friction mechanisms and their effects on the dynamic response of jointed structures, leading to an upgraded and fully validated state-of-the-art modelling approach for nonlinear dynamic analysis.
In WP2, different linear joint identification techniques have been compared and some existing methods were improved further to have better performances. In particular, some guidelines to choose an interface model, useful in practice, are derived. In addition, a new nonlinear identification technique is developed, and the accuracy and robustness of the method when applied to a bolted connection are studied. The main advantage of the method is that it does not have any restriction on the measurement locations. The methods are verified by using case studies, where simulated experimental results are used.
In WP 3, novel methods to compute efficiently the dynamic behavior of modern turbines have been developed and tested, tackling two main challenges:
1. an accurate model of the friction in the interface between blades and disk cannot be built because of the complex physics taking place on the component surfaces in contact,
2. the numerical models of modern turbine components have huge dimensions and simulations can take several hours or more.
The research effort allowed to reach the goals by:
- developing a strategy where the vibration of an assembly of blade and disk is first measured experimentally, leading to a hybrid representation where the contact and friction properties are provided be the experiment whereas the global vibrational behavior is obtained from the numerical model.
- proposing new algorithms to compute the vibration from models with a very large umber of unknowns, by dividing the large model into small portions of the turbine that can be efficiently handled by the many processors of a high performance computer.
- developing new strategies to speed up the iterative processes in parallel computing approaches.
In WP4, the activity focused on enabling new methods from High-Performance Computing for typical engineering simulation codes, by addressing the topics of I/O and task-based programming models. One project developed a system for auto-tuning of I/O parameters using machine-learning techniques which operate transparently in the background without user intervention. A second project developed a library for managing data layout and data-movement across the whole memory hierarchy. Finally, the well-established task-based programming model PyCOMPSs was extended to support new task types for I/O and communication over MPI, respectively Knowledge of the task type is exploited to take better scheduling decisions and overlap these operations with regular compute tasks whenever possible. The software arising from these projects is being published under an open source license.
- developing solutions to allow engineers and researchers alike to assess the position and extent of the zones of relative cyclic motion along the interface.
- developing efficient non-linear model reduction strategy and multi-scale approaches to reduce the size of the problem and enable more complex computations.
- developing and validating prediction tools to study the effect of wear on the dynamics of structures with friction contacts.
- improving the understanding of the friction mechanisms and their effects on the dynamic response of jointed structures, leading to an upgraded and fully validated state-of-the-art modelling approach for nonlinear dynamic analysis.
In WP2, different linear joint identification techniques have been compared and some existing methods were improved further to have better performances. In particular, some guidelines to choose an interface model, useful in practice, are derived. In addition, a new nonlinear identification technique is developed, and the accuracy and robustness of the method when applied to a bolted connection are studied. The main advantage of the method is that it does not have any restriction on the measurement locations. The methods are verified by using case studies, where simulated experimental results are used.
In WP 3, novel methods to compute efficiently the dynamic behavior of modern turbines have been developed and tested, tackling two main challenges:
1. an accurate model of the friction in the interface between blades and disk cannot be built because of the complex physics taking place on the component surfaces in contact,
2. the numerical models of modern turbine components have huge dimensions and simulations can take several hours or more.
The research effort allowed to reach the goals by:
- developing a strategy where the vibration of an assembly of blade and disk is first measured experimentally, leading to a hybrid representation where the contact and friction properties are provided be the experiment whereas the global vibrational behavior is obtained from the numerical model.
- proposing new algorithms to compute the vibration from models with a very large umber of unknowns, by dividing the large model into small portions of the turbine that can be efficiently handled by the many processors of a high performance computer.
- developing new strategies to speed up the iterative processes in parallel computing approaches.
In WP4, the activity focused on enabling new methods from High-Performance Computing for typical engineering simulation codes, by addressing the topics of I/O and task-based programming models. One project developed a system for auto-tuning of I/O parameters using machine-learning techniques which operate transparently in the background without user intervention. A second project developed a library for managing data layout and data-movement across the whole memory hierarchy. Finally, the well-established task-based programming model PyCOMPSs was extended to support new task types for I/O and communication over MPI, respectively Knowledge of the task type is exploited to take better scheduling decisions and overlap these operations with regular compute tasks whenever possible. The software arising from these projects is being published under an open source license.
The EXPERTISE project aimed at answering to two complementary needs:
- the need for mechanical engineers of the challenges related to the employment of high performance computers in mechanical design;
- the need for computer science engineers aware of the possible applications of HPC in the field of structural dynamics and mechanical design.
More accurate and numerically efficient simulations will enable system level predictions and reduce the number of experiments necessary for the product certification.
Therefore, in the short and medium time, the results obtained in the EXPERTISE project will contribute to:
- reducing the development times and costs of turbines
- developing more reliable airctafts and more efficient engines
while in the medium and long time it will contribute to answering to the societal needs for more efficient, less pollutant and more reliable gas turbines for applications related to energy generation, water-turbines, oil & gas extraction and aeronautics. Specifically in aeronautics, the ETN addressed the problems of safety of air transport and of time and cost efficiencies of air transport, included among the priorities for the European Aerospace Industry in the ACARE 2020 vision and in the ACARE Strategic Research Agenda.
Although the focus of EXPERTISE is on turbine, many techniques and methods developed within the project will be applicable in the design of other machines by industrial stake-holders operating in different egineering areas (e.g. automotive, rail, machine tools, aerospace and wind energy sectors).
- the need for mechanical engineers of the challenges related to the employment of high performance computers in mechanical design;
- the need for computer science engineers aware of the possible applications of HPC in the field of structural dynamics and mechanical design.
More accurate and numerically efficient simulations will enable system level predictions and reduce the number of experiments necessary for the product certification.
Therefore, in the short and medium time, the results obtained in the EXPERTISE project will contribute to:
- reducing the development times and costs of turbines
- developing more reliable airctafts and more efficient engines
while in the medium and long time it will contribute to answering to the societal needs for more efficient, less pollutant and more reliable gas turbines for applications related to energy generation, water-turbines, oil & gas extraction and aeronautics. Specifically in aeronautics, the ETN addressed the problems of safety of air transport and of time and cost efficiencies of air transport, included among the priorities for the European Aerospace Industry in the ACARE 2020 vision and in the ACARE Strategic Research Agenda.
Although the focus of EXPERTISE is on turbine, many techniques and methods developed within the project will be applicable in the design of other machines by industrial stake-holders operating in different egineering areas (e.g. automotive, rail, machine tools, aerospace and wind energy sectors).