Electrifying Everything Will Require Multiphysics Modeling

A prototyping problem is emerging in today’s efforts to electrify everything. What works as a lab-bench mockup breaks in reality. Harnessing and safely storing energy at grid scale and in cars, trucks, and planes is a very hard problem that simplified models sometimes can’t touch.

“In electrification, at its core, you have this combination of electromagnetic effects, heat transfer, and structural mechanics in a complicated interplay,” says Bjorn Sjodin, senior vice president of product management at the Stockholm-based software company COMSOL.

COMSOL is an engineering R&D software company that seeks to simulate not just a single phenomenon—for instance, the electromagnetic behavior of a circuit—but rather all the pertinent physics that needs to be simulated for developing new technologies in real-world operating conditions.

Engineers and developers gathered in Burlington, Mass. on 8-10 Oct. for COMSOL’s annual Boston conference, where they discussed engineering simulations via multiple simultaneous physics packages. And multiphysics modeling, as the emerging field is called, has emerged as a component of electrification R&D that is becoming more than just nice-to-have.

“Sometimes, I think some people still see simulation as a fancy R&D thing,” says Niloofar Kamyab, a chemical engineer and applications manager at COMSOL. “Because they see it as a replacement for experiments. But no, experiments still need to be done, though experiments can be done in a more optimized and effective way.”

Can Multiphysics Scale Electrification?

Multiphysics, Kamyab says, can sometimes be only half the game.

“I think when it comes to batteries, there is another attraction when it comes to simulation,” she says. “It’s multi-scale—how batteries can be studied across different scales. You can get in-depth analysis that, if not very hard, I would say is impossible to do experimentally.”

In part, this is because batteries reveal complicated behaviors (and runaway reactions) at the cell level but also in unpredictable new ways at the battery-pack level as well.

“Most of the people who do simulations of battery packs, thermal management is one of their primary concerns,” Kamyab says. “You do this simulation so you know how to avoid it. You recreate a cell that is malfunctioning.” She adds that multiphysics simulation of thermal runaway enables battery engineers to safely test how each design behaves in even the most extreme conditions—in order to stop any battery problems or fires before they could happen.

Wireless charging systems are another area of electrification, with their own thermal challenges. “At higher power levels, localized heating of the coil changes its conductivity,” says Nirmal Paudel, a lead engineer at Veryst Engineering, an engineering consulting firm based in Needham, Mass. And that, he notes, in turn can change the entire circuit as well as the design and performance of all the elements that surround it.

Electric motors and power converters require similar simulation savvy. According to electrical engineer and COMSOL senior application engineer Vignesh Gurusamy, older ways of developing these age-old electrical workhorse technologies are proving less useful today. “The recent surge in electrification across diverse applications demands a more holistic approach as it enables the development of new optimal designs,” Gurusamy says.

And freight transportation: “For trucks, people are investigating, Should we use batteries? Should we use fuel cells?” Sjodin says. “Fuel cells are very multiphysics friendly—fluid flow, heat transfer, chemical reactions, and electrochemical reactions.”

Lastly, there’s the electric grid itself. “The grid is designed for a continuous supply of power,” Sjodin says. “So when you have power sources [like wind and solar] shutting off and on all the time, you have completely new problems.”

Multiphysics in Battery and Electric Motor Design

Taking such an all-in approach to engineering simulations can yield unanticipated upsides as well, says Kamyab. Berlin-based automotive engineering company IAV, for example, is developing powertrain systems that integrate multiple battery formats and chemistries in a single pack. “Sodium ion cannot give you the energy that lithium ion can give,” Kamyab says. “So they came up with a blend of chemistries, to get the benefits of each, and then designed a thermal management that matches all the chemistries.”

Jakob Hilgert, who works as a technical consultant at IAV, recently contributed to a COMSOL industry case study. In it, Hilgert described the design of a dual-chemistry battery pack that combines sodium-ion cells with a more costly lithium solid-state battery.

Hilgert says that using multiphysics simulation enabled the IAV team to play the two chemistries’ different properties off of each other. “If we have some cells that can operate at high temperatures and some cells that can operate at low temperatures, it is beneficial to take the exhaust heat of the higher-running cells to heat up the lower-running cells, and vice versa,” Hilgert said. “That’s why we came up with a cooling system that shifts the energy from cells that want to be in a cooler state to cells that want to be in a hotter state.”

According to Sjodin, IAV is part of a larger trend in a range of industries that are impacted by the electrification of everything. “Algorithmic improvements and hardware improvements multiply together,” he says. “That’s the future of multiphysics simulation. It will allow you to simulate larger and larger, more realistic systems.”

According to Gurusamy, GPU accelerators and surrogate models allow for bigger jumps in electric motor capabilities and efficiencies. Even seemingly simple components like the windings of copper wire in a motor core (called stators) provide parameters that multiphysics can optimize.

“A primary frontier in electric motor development is pushing power density and efficiency to new heights, with thermal management emerging as a key challenge,” Gurusamy says. “Multiphysics models that couple electromagnetic and thermal simulations incorporate temperature-dependent behavior in stator windings and magnetic materials.”

Simulation is also changing the wireless charging world, Paudel says. “Traditional design cycles tweak coil geometry,” he says. “Today, integrated multiphysics platforms enable exploration of new charging architectures,” including flexible charging textiles and smart surfaces that adapt in real-time.

And batteries, according to Kamyab, are continuing a push toward higher power densities and lower price points. Which is changing not just the industries where batteries are already used, like consumer electronics and EVs. Higher-capacity batteries are also driving new industries like electric vertical take-off and landing aircraft (eVTOLs).

“The reason that many ideas that we had 30 years ago are becoming a reality is now we have the batteries to power them,” Kamyab says. “That was the bottleneck for many years. … And as we continue to push battery technology forward, who knows what new technologies and applications we’re making possible next.”

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