CEEC CoE

Introduction to Computational Fluid Dynamics
2024-09-16 - 2024-09-20 | HLRS University of Stuttgart, Nobelstraße 19, Stuttgart, 70569, Germany
Join our Anna Schwarz as one of the instructors for the reoccuring “Introduction to Computational Fluid Dynamics” course organized by HLRS, IAG (University of Stuttgart) and the
Institute of Software Methods for Product Virtualisation (DLR).

'Enabling mixed-precision with the help of tools: A Nekbone case study' at PPAM24
2024-09-09 12:05 - 12:25 (Europe/Paris) | Ostrava, Czechia, Ostrava, Czech Republic
If you’re going to PPAM24 September 8 – 11 in Ostrava, Czechia, make sure to check out the talk by Yanxiang Chen from our partner UMU on their progress implementing and optimizing mixed precision in Nekbone toward its integration in Neko and NekRS. The accompanying paper is also available as a pre-print online: https://arxiv.org/pdf/2405.11065

Keynote Lecture at parCFD
2024-09-03 18:15 - 19:00 | Universitätsclub Bonn e.V., Konviktstr.9, Bonn, 53113, Germany
Join our own Niclas Jansson for his keynote lecture as an invited speaker at the 35th Parallel CFD International Conference 2024 in Bonn, Germany.

A continuous benchmarking pipeline for performance engineering on different architectures for the waLBerla framework
2024-09-03 16:50 - 17:10 | Universitätsclub Bonn e.V., Konviktstr.9, Bonn, 53113, Germany
Come listen to our own Kajol Kulkarni presenting in mini-symposium 4 at parCFD on our work with benchmarking of waLBerla.

Mini-Symposium 4: Modernizing CFD: Exploring CI/CD for Improved Software Development Life Cycle
2024-09-02 00:00 - 2024-09-03 23:59 | Universitätsclub Bonn e.V., Konviktstr.9, Bonn, 53113, Germany
Join CEEC at the 35th Parallel CFD International Conference 2024 this fall in Bonn, Germany.
In the Mini-Symposium 4: Modernizing CFD: Exploring CI/CD for Improved Software Development Life Cycle, CEEC will be joined by sister European Centers of Excellence EXCELLERAT P2, EOCOE3, and HIDALGO 2 supported by the coordination activity CASTIEL 2. This symposium will focus on the role of Continuous Integration/Continuous Deployment (CI/CD) in guaranteeing CFD simulation applications’ stability, reproducibility, portability, and performance.

Task-decomposed Overlapped Pressure Preconditioner for Sustained Strong Scalability on Accelerated Pre-exascale Systems
2024-07-16 17:30 - 18:00
Join CEEC in Kobe, Japan at the 12th bi-annual ICCFD conference this July! Niclas Jansson will be presenting “Task-decomposed Overlapped Pressure Preconditioner for Sustained Strong Scalability on Accelerated Pre-exascale Systems” as part of the technical program.

Entropy stable subcell shock capturing scheme for high-order discontinuous Galerkin methods on moving meshes
2024-06-04 17:00 - 19:00 | Lisbon Congress Centre, Praça das Indústrias 1, Lisboa, 1300-307, Portugal
If you’re not in the mini-symposium with Samual, make sure to see the talk ‘Entropy stable subcell shock capturing scheme for high-order discontinuous Galerkin methods on moving meshes’ presented by Anna Schwarz in room 1.14.

A Fluid-Solid Coupled Micromechanical Simulation of Piping Erosion During the Installation of a Suction Bucket for the Foundation of an Offshore Wind Turbine
2024-06-04 17:00 - 19:00 | Lisbon Congress Centre, Praça das Indústrias 1, Lisboa, 1300-307, Portugal
If you’re not in the mini-symposium with Anna, make sure to come see Samuel Kemmler’s talk ‘A Fluid-Solid Coupled Micromechanical Simulation of Piping Erosion During the Installation of a Suction Bucket for the Foundation of an Offshore Wind Turbine’. It is part of the mini-symposium 020 – Advancements in Offshore Wind Structures , which will be held in Room 2.02.

ECCOMAS MS088 - State-of-the-art Machine Learning Techniques For Computational Fluid Dynamics
2024-06-04 14:30 - 16:30 | Lisbon Congress Centre, Praça das Indústrias 1, Lisboa, 1300-307, Portugal
Come join our Anna Schwarz, Jens Keim, and Andrea Beck for the mini-simposium “State-of-the-art Machine Learning Techniques For Computational Fluid Dynamics” in room 2.01.
Machine learning (ML) in scientific applications including computational fluid dynamics (CFD) is a growing field of research. However, ML can be less stable and more prone to errors in CFD because of its complexity relative to e.g. game theory. Thus, recent research has concentrated on reinforcement learning (RL) or physics-informed methods applied to CFD. Common examples for RL in CFD are flow control, turbulence modeling and shock capturing. An additional and continuously growing field of research which alleviates the common problems of ML in CFD is physics-informed neural networks (PINNs). In general, recently, modified versions of classical PINNs have been proposed to push their limitations and make them more tailored to CFD. With these considerations in mind, the objective of this minisymposium is to discuss the applicability, predictive performance and limitations of state-of-the-art ML methods in CFD.

Neko: A modern, Portable, and Scalable Framework for High-Fidelity Computational Fluid Dynamics
2024-06-04 10:30 - 12:30 | Lisbon Congress Centre, Praça das Indústrias 1, Lisboa, 1300-307, Portugal
If you’ll be at ECCOMAS 2024, check out ‘Neko: A modern, Portable, and Scalable Framework for High-Fidelity Computational Fluid Dynamics’ presented by Niclas Jansson on the terrace.

Workshop on Readiness of HPC Extreme-scale Applications
2024-05-16 14:00 - 18:00 | Congress Center Hamburg, Congressplatz 1, Hamburg, 20355, Germany
If you have a workshop pass, please come hear about application development in the European HPC Centres of Excellence including CEEC!
“this ISC workshop has been organised to provide a forum to consider common challenges, ideas, solutions, and opportunities from the point of view of HPC applications developers preparing for exa-scale. ISC is the leading HPC conference in Europe, gathering not only the main HPC vendors and providers but also developers and standardizing committees from programming models, compilers, and other system software. However, we still need one of the key players in this ecosystem, the HPC applications! With this workshop, we seek to cover this gap and expand the ISC conference to HPC code developers.”

Neko: A Modern, Portable, and Scalable Framework for Extreme-Scale Computational Fluid Dynamics
2024-05-15 16:00 - 16:20 | Congress Center Hamburg, Congressplatz 1, Hamburg, 20355, Germany
Recent trends and advancements in including more diverse and heterogeneous hardware in High-Performance Computing are challenging scientific software developers in their pursuit of good performance and efficient numerical methods. As a result, the well-known maxim “software outlives hardware” may no longer necessarily hold true, and researchers are today forced to re-factor their codes to leverage these powerful new heterogeneous systems. We present Neko – a portable framework for high-fidelity spectral element flow simulations. Unlike prior works, Neko adopts a modern object-oriented Fortran 2008 approach, allowing multi-tier abstractions of the solver stack and facilitating various hard- ware backends ranging from general-purpose processors, accelerators down to exotic vector processors and Field Programmable Gate Arrays (FPGAs) via Neko’s device abstraction layer. Focusing on Neko’s performance and exascale readiness, we outline the optimisation and algorithmic work necessary to ensure scalability and performance portability across a wide range of platforms. Finally, we present performance measurements on a wide range of accelerated computing platforms, including the EuroHPC pre-exascale system LUMI and Leonardo, where Neko achieves excellent parallel efficiency for an extreme-scale direct numerical simulation (DNS) of turbulent thermal convection using up to 80% of the entire LUMI supercomputer.

Center of Excellence in Exascale CFD at ISC High-Performance 2024
2024-05-15 14:15 - 14:45 | Congress Center Hamburg, Congressplatz 1, Hamburg, 20355, Germany
In addition to the technical programming, we will be presenting our last year of work at the EuroHPC Joint Undertaking booth J30 on Wednesday afternoon. Come hear about our latest work and then head over to Niclas’ talk on Neko later in the afternoon.

CEEC at the 12th National Conference on Flow Phenomena
2024-04-16 16:15 - 17:00
We will be presenting interem results from our work at the 12th National Conference on Flow Phenomena in Thessaloniki, Greece. If you’re going to be around (and speak Greek) please come say hello!

CEEC at Direct and Large Eddy Simulation
2024-04-10 - 2024-04-12 | Friedrich-Alexander-Universität (FAU), Erlangen-Nürnberg, Germany, Schloßplatz 4, Erlangen, Bayern, 91054, Germany
The bi-annual Workshop series on Direct and Large Eddy Simulation (DLES) which started in 1994 focuses on modern techniques to simulate turbulent flows based on the partial or full resolution of the instantaneous turbulent flow structure. With the growing capacities of modern computers, this approach has been gaining more and more interest over the years and will undoubtedly be further enhanced and applied.
The goal of the bi-annual DLES workshop series is to establish the state-of-the-art of DNS, LES and related techniques for the computation and modelling of turbulent and transitional flows.
Hybrid modelling techniques, e.g. based on a combination of LES and RANS approaches, also fall into this category and are covered as well. This gathering of specialists in the field will be a unique opportunity for discussions about recent advances in the prediction, understanding and control of turbulent flows in academic and industrial applications.
The CEEC contributions to this year’s program are:

Evaluation of Dynamic Sigma Sub-Grid Scale Models
MS Talk: Numerical Investigation of a Tandem Wing Configuration in Transonic Flow Regime
MS Talk: GALEXI: Scale-resolving simulations of compressible turbulence on GPU-accelerated systems

Registration:

Late registration closes April 12, 2024

The Organizing Committee of DLES14:

Philipp Schlatter (FAU Erlangen-Nürnberg, Germany)
Cristian Marchioli (University of Udine, Italy)
Maria Vittoria Salvetti (University of Pisa, Italy)
Stefan Hickel (TU Delft, The Netherlands)

Second CEEC Community Workshop - Maximizing CFD Code Efficiency: A workshop on Continuous Integration, Benchmarking, and Testing in Cluster Environments
2024-03-25 09:00 - 16:00 | Friedrich-Alexander-Universität (FAU), Erlangen-Nürnberg, Germany, Schloßplatz 4, Erlangen, Bayern, 91054, Germany
CI/CD has revolutionized software development practices by offering streamlined workflows that enhance productivity, reliability, and agility in delivering software products. When it comes to massive codes designed for performing physics simulations, cluster computing environments represent a cornerstone of modern computational infrastructure, offering unparalleled capabilities for parallel processing and data-intensive applications. Continuous integration (CI), benchmarking, and testing play pivotal roles in optimizing the performance of applications deployed in cluster settings. This workshop delves into the adaptation of CI/CD methodologies to HPC environments. This workshop aims to equip participants with the knowledge and skills to leverage CI/CD practices effectively on a test cluster and then visualise the results. By the end of the workshop, participants will be equipped with the expertise to implement CI/CD workflows effectively on supercomputer machines.

Participation is free!
Attendees may bring their own code (git repo) or use a test code provided by the organizers.
Attendance is also hybrid, either on-site or online.

Register Here!

Agenda

9:00 – 9:15: Opening
9:15 – 10:45: General introduction to CI/CD and cluster access
10:45 – 11:00: break
11:00 – 12:15 – setting up a simple test repository
12:15 – 13:00: lunch break
13:00 – 16:00: hands-on session on CB using test cluster and Visualization

PLENARY: EuroHPC Users: How Are They Exploiting the Current EuroHPC Systems & Will Exploit Future Exascale Capabilities?,
2024-03-19 17:50 - 18:45 | Flanders Meeting and Convention Centre, A Room with a ZOO, Koningin Astridplein 20-26, Antwerp, 2018, Belgium
If you’re attending the EuroHPC Summit Week this month in Antwerp, make sure to join our Niclas Jansson for a PLENARY, “EuroHPC Users: How Are They Exploiting the Current EuroHPC Systems & Will Exploit Future Exascale Capabilities?”
17:15→18:45

CEEC at the Euro HPC Summit Poster Session
2024-03-19 14:15 - 15:15 | Flanders Meeting and Convention Centre, A Room with a ZOO, Koningin Astridplein 20-26, Antwerp, 2018, Belgium
If you’re interested in our progress over the last year or hoping to ask us questions about our plans for the future, don’t miss the chance to talk with our own Niclas Jansson at the first poster session of the Euro HPC Summit on Tuesday, March 19th!

Code of the Month vol.6 “Neko by CEEC” — PUBLIC event
2024-01-31 11:00 - 12:00 | Online
Recent trends and advancements including more diverse and heterogeneous hardware in High-Performance Computing are challenging scientific software developers in their pursuit of good performance and efficient numerical methods. As a result, the well-known maxim “software outlives hardware” may no longer necessarily hold true, and researchers are today forced to re-factor their codes to leverage these powerful new heterogeneous systems. We present Neko – a portable framework for high-fidelity spectral element flow simulations. Unlike prior works, Neko adopts a modern object-oriented Fortran 2008 approach, allowing multi-tier abstractions of the solver stack and facilitating various hard- ware backends ranging from general-purpose processors, accelerators down to exotic vector processors and Field Programmable Gate Arrays (FPGAs) via Neko’s device abstraction layer. Focusing on Neko’s performance and exascale readiness, we outline the optimisation and algorithmic work necessary to ensure scalability and performance portability across a wide range of platforms. Finally, we present performance measurements on a wide range of accelerated computing platforms, including the EuroHPC pre-exascale systems LUMI and Leonardo, where Neko achieves excellent parallel efficiency for an extreme-scale direct numerical simulation (DNS) of turbulent thermal convection using up to 80% of the entire LUMI supercomputer.

1st CEEC Community Workshop: Energy-Efficient, Fault Resilient, and Scalable Solvers for CFD Codes
2023-12-13 14:00 - 17:00
Join us for our first annual community workshop! The energy consumption constraint for large-scale computing encourages scientists to revise the architecture design of hardware but also applications, algorithms, as well as the underlying working/ storage precision. The main aim is to make the computations energy-efficient (aka sustainable) and robust numerically but also in terms of fault tolerance. On the level of algorithmic solutions, we propose to utilize all provided resources wisely by exhibiting algorithms to computation overlapping but even more communication overlapping strategies. We also promote mixed-precision strategies with the aid of computer arithmetic tools like VerifiCarlo and its variable precision backend. Hence, before lowering precision, one must ensure that the simulation is numerically correct, e.g. by relying on alternative floating-point models/ rounding to pinpoint numerical bugs and to estimate the accuracy. We also work on fault tolerant and resilient algorithms, adaptivity and meshing/ mesh refinement that adapt to the heterogeneous nature of current machines. Another issue discussed in the workshop is the adaptation of adjoint-based topology optimization methods to spectral-element CFD codes. Therefore, in this workshop, we will share our approaches, lessons learnt with preliminary results, and outline perspectives for the upcoming three years of the project.
Agenda:

14:00 Opening
14:05 Niclas Jansson, KTH. “Scalable task-parallel multigrid solvers on GPUs”
14:30 Dinesh Parthasarathy, FAU. “Optimizing multigrid solvers using grammar-guided genetic programming”
14:55 Roman Iakymchuk, UmU. “A tool-driven approach toward mixed-precision and sustainable solvers for CFD codes”
15:20 Break
15:35 Eman Bagheri and Manuel Münsch, FAU. “Fault-resilient algorithms for Exascale CFD”
16:00 Adam Peplinski, KTH. “h-type adaptive mesh refinement in spectral-element solvers: Application to Nek5000 and Neko”
16:25 Eddie Wadbro and Martin Berggren, UmU. “Topology optimization in spectral-element codes”
16:50 Summary

Register for free here!

Exploring the Ultimate Regime of Turbulent Rayleigh–Bénard Convection through Unprecedented Spectral-Element Simulations
2023-11-16 00:30 - 01:30
Don’t miss the official presentation of the work on NEKO that is nominated for the Gordon Bell Prize!
Official Description: We detail our developments in the high-fidelity spectral-element code Neko that are essential for unprecedented large-scale direct numerical simulations of fully developed turbulence. Major innovations are modular multi-backend design enabling performance portability across a wide range of GPUs and CPUs, a GPU-optimized preconditioner with task overlapping for the pressure-Poisson equation and in-situ data compression. We carry out initial runs of Rayleigh–Bénard Convection (RBC) at extreme scale on the LUMI and Leonardo supercomputers. We show how Neko is able to strongly scale to 16,384 GPUs and obtain results that are not possible without careful consideration and optimization of the entire simulation workflow. These developments in Neko will help resolving the long-standing question regarding the ultimate regime in RBC.

Neko – a European code development effort shortlisted for the 2023 ACM Gordon Bell Prize
2023-11-15 20:30 - 21:00
Come listen to our own Niclas Jansson talk about his work on NEKO, which has been shortlisted for the 2023 ACM Gordon Bell Prize. We have the great fortune of being able to build on this work during the cEEC project. Learn more in his interview at the LUMI stand (booth 206)!

Precision in linear algebra solvers and its cascade impact on applications
2023-10-11 11:15 - 12:00
Until recent years, linear algebra solvers were predominantly operating with double precision or binary64. With the advent of AI, in particular deep learning, lower floating-point precisions formats were introduced to accommodate the need of such computations; now the spectrum is shifted to fixed point and integer arithmetic, expanding to block floating point arithmetic. This change has also impacted the linear algebra algorithm development where the concept of mixed-precision was introduced for faster but still reliable solvers. In this talk, I would like to provide a brief overview on mixed-precision algorithmic work, introduce to my own strategy of mixing precisions in a controllable way, and provide preliminary results with applications.

VPREC to analyze the precision appetites and numerical abnormalities of several proxy applications
2023-08-24 08:30 - 10:10
The energy consumption constraint for large-scale computing encourages scientists to revise the architecture design of hardware but also applications, algorithms, as well as the underlying working/ storage precision. We introduce an approach to address the issue of sustainable computations from the perspective of computer arithmetic tools. We employ the variable precision backend (VPREC) to identify parts of code that can benefit from smaller floating-point formats. Finally, we show preliminary results on several proxy applications.

Sustainable and Reliable Computing with Tools: Analyzing Precision Appetites of CFD Applications with VerifiCarlo
2023-06-27 16:30 - 17:00
The energy consumption constraint for large-scale computing encourages scientists to revise the architecture design of hardware but also applications, algorithms, as well as the underlying working/ storage precision. The main aim is to make the computing cost sustainable and apply the lagom principle (”not too much, not too little, the right amount”), especially when it comes to working/ storage precision. Thus, I will introduce an approach to address the issue of sustainable, but still reliable, computations from the perspective of computer arithmetic tools. Before lowering precision, one needs to ensure that the simulation is numerically correct, e.g. by relying on alternative floating-point models/ rounding to pinpoint numerical bugs and to estimate the accuracy. We employ VerifiCarlo and its variable precision backend to identify the parts of the code that benefit from smaller floating-point formats. Finally, we show preliminary results on proxies of CFD applications.

MS4F - Cross-Cutting Aspects of Exploiting Exascale Platforms for High-Fidelity CFD in Turbulence Research
2023-06-27 16:00 - 18:00
With the arrival of exascale computing, the theoretical computational performance has increased, opening up for unprecedented simulation capabilities for Computational Fluid Dynamics (CFD) applications. While offering high theoretical peak performance and high memory bandwidth, to efficiently exploit these systems, complex programming models and significant programming investments are necessary. Furthermore, most known pre and exascale systems currently planned or installed, e.g. Frontier, Leonardo and LUMI, contain a large fraction of accelerators. Thus, the challenge of porting and tuning scientific codes for these new platforms can no longer be ignored. However, established CFD codes build on years of verification and validation of their underlying numerical methods, potentially preventing a complete rewrite and rendering disruptive code changes a delicate task. Therefore, porting established codes to accelerators poses several interdisciplinary challenges, from formulating suitable numerical methods to applying sound software engineering practices to cope with disruptive code changes. The wide range of topics makes the exascale CFD transition relevant to a broader audience, extending outside the traditional fluid dynamics community. This minisymposium aims at bringing together the CFD community as a whole, from domain scientists to HPC experts, to discuss current and future challenges towards enabling exascale fluid dynamics simulations on anticipated accelerated systems.

Neko: A Modern, Portable, and Scalable Framework for High-Fidelity Computational Fluid Dynamics
2023-06-01 17:00 - 17:30
Recent trends and advancements including more diverse and heterogeneous hardware in High-Performance Computing are challenging scientific software developers in their pursuit of good performance and efficient numerical methods. As a result, the well-known maxim “software outlives hardware” may no longer necessarily hold true, and researchers are today forced to re-factor their codes to leverage these powerful new heterogeneous systems. We present Neko – a portable framework for high-fidelity spectral element flow simulations. Unlike prior works, Neko adopts a modern object-oriented Fortran 2008 approach, allowing multi-tier abstractions of the solver stack and facilitating various hardware backends ranging from general-purpose processors, accelerators down to exotic vector processors and Field-Programmable Gate Arrays (FPGAs) via Neko’s device abstraction layer. Focusing on the performance and accuracy of Neko, we show the first direct numerical simulation (DNS) of a Flettner rotor submerged in a turbulent boundary layer, observing excellent agreement of lift with experimental data. Using a mesh with five million spectral elements, which turns into more than a billion unique degrees of freedom, the simulation requires less than three days to complete on accelerated systems compared to weeks on traditional non-accelerated systems. Finally, we present performance measurements on a wide range of accelerated computing platforms, including the EuroHPC pre-exascale system LUMI, where Neko achieves excellent parallel efficiency for a large DNS of turbulent fluid flow using up to 80% of the entire LUMI supercomputer.

Reliable and sustainable computations: An application-driven approach
2023-05-24 14:40 - 15:00
In this talk, Roman Iakymchuk presents his work on accuracy and reproducibility assuring strategies for parallel iterative solvers that may not hold due to the non-associativity of floating-point operations. These strategies primarily rely on guarding every bit of result until final rounding, hence they can be costly. The energy consumption constraint for large-scale computing encourages scientists to revise the architecture design of hardware but also applications, algorithms, as well as the underlying working/ storage precision. The main aim is to make the computing cost sustainable and apply the lagom principle (”not too much, not too little, the right amount”), especially when it comes to working/ storage precision. Thus, he will introduce an approach to address the issue of sustainable, but still reliable, computations from the perspective of computer arithmetic tools. Before lowering precision, one must ensure that the simulation is numerically correct, e.g. by relying on alternative floating-point models/ rounding to pinpoint numerical bugs and to estimate the accuracy. We employ VerifiCarlo and its variable precision backend to identify the parts of the code that benefit from smaller floating-point formats. Finally, we show preliminary results on proxy applications.

Introducing CEEC at ISC23
2023-05-24 11:45 - 12:15
Come learn about CEEC at the European HPC Joint Undertaking booth at ISC23! We’ll give a quick overview of the project and be eager to answer all your questions about CFD, our lighthouse cases, and how our work can help address grand challenges.

ISC High Performance 2023
2023-05-21 - 2023-05-25
Come visit us at the EuroHPC Joint Undertaking booth B201 at ISC! We will be there all week to answer your questions about our goals, future work, and its potential impact on the field of computational fluid dynamics. Once again in Hamburg, the annual ISC event is sure to offer something for every person interested in HPC, machine learning, data analytics, and quantum computing.
