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Pressure distribution in the lubricant of crank bearings (rainbow color plot), von Mises stresse (blue color plot), and displacement of the bearings (orbit plot) resulting from a rotordynamics analysis using the new COMSOL Rotordynamics module.

Making Multiphysics fast and convenient

Mimicking real life interactions in complex products like automobiles or aircraft often requires a Multiphysics approach. It requires combining, for example, simulations of combustion, heat transfer, fluid flow, and stress analysis to truly understand how an engine is going to perform reliably in real world conditions.

As computer memory grows, and software developers learn how to create efficient codes, practical Multiphysics is expanding. However, challenges remain beyond the technical—the sheer intellectual complexity in creating simulations and scenarios that span such a range of knowledge. Increasing technical capabilities highlight some human limitations. Creating a valid Multiphysics model is often confined to a small group of highly specialized, highly educated ‘power’ users.

Sweden-based CAE simulation tools specialist COMSOL is tackling this human complexity problem in two ways: specialized modules and dedicated "apps" deployed in Windows or even on a smartphone. Both approaches are aimed at making software easier to user for a broader group of engineers. This is especially important for mobility-industry engineers and managers, explained Dr. Valerio Marra, COMSOL's Marketing Director.

“Putting together an R&D team is quite an endeavor—to find them, to train them in your industry and for them to find the right tools,” Dr. Marra told Automotive Engineering. “If you want to keep up with progress in innovation in the industry, you have to free up their time.” He emphasized that the answer is not always to hire more engineers. These additional engineers would need training on the core COMSOL Multiphysics product as well as deep understanding of the underlying physics.

“What managers should know is there is a technology now that engineers can use to package the complexity of their knowledge into an 'app,' so that other engineers can go on with their design work,” he said.

Building apps and interfaces

COMSOL is not the only CAE company offering such tools for packaging and hiding complexity. Offering it as a specialty in Multiphysics should come as a welcome addition for those attempting to solve higher fidelity problems where multidisciplinary interactions are key.

A COMSOL app is a multiphysics model wrapped in a custom user interface. The user interface is built through a graphical, interactive tool called the Application Builder. Apps can be deployed as a client in Windows, or even through a web browser, by connecting to a local installation of COMSOL Server software. They can also appear on a smartphone.

“Building an App is especially useful when there are repetitive operations that need to be done, perhaps even on a routine basis. When accessing complex software becomes a problem, accessing the App that hides much of that complexity becomes a valuable asset,” explained Marra.

The company claims that custom applications can be created for anyone from technicians, support staff, designers, to customer service representatives, “empowering them to make on-the-fly design iterations and report generation,” he said. 

Specialty modules

In a variation on packaging complexity, the latest update of the COMSOL suite includes the new Rotordynamics Module. It helps engineers in analyzing vibrations due to gyroscopic effects in rotating machinery, evaluating critical speed, whirl, and bearings. It is targeted for users that design or evaluate turbochargers, turbines, pumps and electrical machinery in the automotive, aerospace, energy and marine sectors among others.

The company notes that additional tools for modeling geared rotors are available when the Rotordynamics Module is combined with the Multibody Dynamics Module. Postprocessing capabilities include creating Campbell diagrams, modal orbits, harmonic orbits, waterfall plots, and whirl plots. The new module is in addition to 28 other modules for specialty applications, including electrical, structural & acoustics, fluid & heat, and chemical applications. The core COMSOL Multiphysics software is required to run any of these add-on products.

A related improvement to the latest release of COMSOL is speedier processing of larger models and meshes. The company emphasizes models with several thousand domains and boundaries, with functionality speedups including a 10-times speed improvement in selections of domains and boundaries, virtual operations for mesh preparation, swept meshing, and OpenGL rendering and a 5-times improvement in CAD imports.

One of the issues with simulating Multiphysics in the past has been the size of the resulting numerical model, but increasingly fast and inexpensive computing is giving numerical specialists the opportunity to fine-tune codes to ingest and compute ever larger models.

For related information, see "Simulation apps for virtual prototyping" (

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