Elmer: versatile multiphysical modeling
Elmer is a versatile multiphysical simulation software package developed mainly at CSC. Its user base spans from academic researchers to companies around the world. Work on Elmer began in collaboration with universities in 1995.
Elmer is one of the leading multiphysical simulation software. Its key strength is versatility: it covers many scientific disciplines and runs on a wide range of platforms. In 2008, Elmer was licensed as open-source software, and the lack of license fees makes it especially attractive for research groups and small companies. As open-source software, it can also be tailored for diverse needs.
Elmer is based on the finite element method (FEM) and includes solvers for a wide range of application areas, including computational fluid dynamics, structural mechanics, electromagnetics, heat transfer, acoustics, and glacier modeling. In practice, Elmer solves partial differential equations numerically.
“Elmer has a long history, so over time we’ve been able to develop solvers for many application areas. In terms of versatility, Elmer is among the top modeling tools available. It includes ready-made, well-documented solvers,” said Peter Råback, the Head of Elmer Development.
Part of Elmer’s versatility comes from its availability on multiple platforms, from laptops to supercomputers. The total number of Elmer users is difficult to estimate.
The Windows version of Elmer is downloaded about 40,000 times per year from the nic.funet.fi service. Linux versions have multiple distribution channels, making accurate download numbers harder to determine. Råback estimated that the number of Linux users is likely no higher than on Windows, but Linux users tend to be Elmer power users. Elmer can also be run on CSC’s supercomputers. On supercomputers, Elmer uses CPU nodes.
“For a long time, Elmer development didn’t require us to think much about architecture. Elmer is essentially MPI code. We simply added new features without having to reconsider the implementation side. The arrival of GPU nodes brings new challenges—not just for us, but for everyone. The finite element method is, by nature, a challenging fit for GPUs,” Råback explained.
Most visible domains: electromagnetics and glacier modeling
Today, Elmer’s most visible application areas are glacier modeling and computational electromagnetics.
One of Elmer’s major milestones was its selection in 2022 for the Center of Excellence in High-Speed Electromechanical Energy Conversion Systems (HiECSs). This provides long-term opportunities and funding to further develop the software.
In a newly funded Chips JU project Open Design Environment for European Chips – Analog and Mixed Signal, linked to the EU’s Chips Act initiative, Elmer is used as a field solver integrated in the design workflow of analog circuits. The project brings together major European research institutes and companies, 25 partners in total. From Finland, Aalto University and three companies are participating. For CSC, a key aspect is the continuous collaboration with IQM within the framework of the project.
“In electromagnetics, the number of industrial users is significant, about half. Industry users typically have a specific focus, and if Elmer fits their needs, they tend to use it over the long term. Many SMEs cannot afford expensive commercial licenses, so they benefit from open-source software and are willing to invest more time in learning it,” Råback said.
Elmer/Ice is one of the world’s leading software for modeling ice dynamics. Among all Elmer components, Elmer/Ice has the greatest level of international contribution. Elmer/Ice is not only software, but also a global research community, and the software is actively developed in multiple EU-funded projects.
“In glacier modeling, almost all users are academic. They’re an altruistic, world‑saving community, and they’re great to work with. Their goal is to understand how climate change affects glaciers. Those lofty aims bring an extra sense of meaning to the work,” Råback noted.
The adoption of Elmer in glaciology also involved coincidences and personal connections. Austrian researcher Thomas Zwinger had been modeling avalanches in Austria. In 2001, Zwinger joined CSC and met French glacier modeler Olivier Gagliardini from IGE, Grenoble during a visit of a conference. Gagliardini later visited CSC as a research fellow, and this collaboration sparked the development of Elmer/Ice for glacier and ice-sheet modeling.
“There is no commercial software in ice sheet modelling so there are more users to open-source solutions like Elmer/Ice, and community is built around software. Elmer/Ice users have started many international joint research projects, and they also organize training on Elmer/Ice,” said Thomas Zwinger, Senior Application Specialist at CSC.
As Elmer/Ice is an open-source code, the exact number of users is hard to estimate.
“The core is the five Elmer developers at CSC. In UK and France, there are about 10 contributors, who develop and share features for Elmer/Ice. The total amount is around 700, of which about 30 are power users,” Thomas Zwinger estimated.
Multiple use cases
Quantum computing offers no advantage for the finite element method. Instead, Elmer’s connection to quantum technology goes the other way: Elmer has been used in the design of quantum circuits. CSC and IQM extended Elmer’s capabilities so that it can perform computationally demanding electromagnetic simulations required for optimizing QPU components.
Elmer also has a long history in industrial applications. The first use case in radiative heat transfer was silicon crystal growth in collaboration with Okmetic and now collaboration with Outokumpu is building on the same foundation. CSC collaborated with multiple microsystems companies as well, including Vaisala. Elmer’s acoustic modeling has been used by Nokia for several phone models.
236 peer reviewed scientific papers have been published based on Elmer/Ice simulations, and many have contributed to IPCC assessment reports. Elmer/Ice has been used to model ice flows in glaciers and ice sheets, sea level rise caused by melting and collapsing ice sheets and study the formation of rapid glacial outburst floods (jökulhlaups).
“Eustatic sea level rise in near future is dominated by vanishing ice sheets and glaciers. Quantification of this component is essential for planning mitigation of rising waters. In TerraDT project, including Elmer/Ice as a component in the ICON Digital Twin shall investigate future sea level rise.”
“Then in CryosSCOPE project we investigate methane release by retreating glaciers and permafrost in Svalbard. In same project, we are using Elmer/Ice to train an AI model to investigate risks of future glacier lake outburst floods in Alps,” Thomas Zwinger continued.
Elmer/Ice has also been used in research conducted by CSC and Posiva related to final disposal of highly active nuclear spent fuel. Using Elmer/Ice, researchers implemented a coupled permafrost–groundwater model to study the future conditions around the disposal site in Eurajoki.
Photo: Thomas Zwinger (on left) and Peter Råback from CSC. Photo: Tommi Kutilainen, CSC.
Author:
Tommi Kutilainen
Tommi Kutilainen works with communications at CSC, especially in the fields of science and research.
