Electric Machines
Innovative solutions for thermal design of electric machines
The electrification of the industrialized world is accelerating and Electric Machines are responsible for 60% of energy consumption world wide. With the need to package electric machines in ever smaller spaces as well as the need to squeeze ever more power from a given machine so the thermal performance of a machine becomes a critical feature.
  • This exploded view of an electric motor shows the surface temperature distribution and polyhedral mesh generated with STAR-CCM+ for a forced air cooling simulation.
  • The image shows a typical model where the 2D sector losses have been mapped on to a full revolution 3D body
  • A water jacket cooled motor: STAR-CCM+ in combination with SPEED is an integrated toolset for virtual prototyping of electric machines which delivers the power of computational fluid dynamics and heat transfer simulation technology.
  • This early example of the finite-volume-based STAR-CCM+ EM Field Solver shows proximity effects in a stranded conductor.
  • An exploded view of the Grundfos MAGNA-series circulator pump: tight space restrictions lead to a complex geometry for in-depth cooling analysis (image courtesy of Grundfos, Denmark).
  • This image shows a cross-section view of the electric current density and magnitude of the magnetic flux density in an electric machine.

CD-adapco’s flagship computer aided engineering code, STAR-CCM+, is a central tool in the prediction of component temperatures within both early state designs and very mature, highly complex CAD models. The thermal challenge within electric machines is to provide a thermal pathway for electromagnetic losses and conduction losses to leave the machine without critical component temperatures within the machine being reached. STAR-CCM+ captures all modes of heat transfers (conduction, convection &radiation) and can be applied to air cooling, water cooling and even oil spray or bath cooling. Such methods reveal a complete thermal understanding of the electric machine and design changes can be suggested.

The origins of the temperature rise within an electric machines are through the various electromagnetic and conducting losses during operation. CD-adapco has enabled a close connection between STAR-CCM+ and the electric machine design package, SPEED, also a CD-adapco product. SPEED provides a 2D spatial distribution of the electromagnetic losses within the electric machine. This spatial loss is mapped on to the 3D components within the thermal simulation in an easy to use graphical user interface. Using mapped losses, rather than integral loss values imposed uniformly (which is the traditional way to apply the thermal load) produces more accurate results and higher localised temperatures. Such mapping of losses is not limited to our own electric machine design package and can be done from a large number of commercial electromagnetic simulation tools, e.g. JMAG or FLUX. The recorded webinars available in our videos section of this page highlight the process or contact your local CD-adapco representative to see how STAR-CCM+ can fit in to your workflow.
As well as reading in electromagnetic loss distributions from a wide range of commercial tools, STAR-CCM+ further expedites the setup of electric machine problems by creating the detailed CAD model automatically. This benefit is unique to SPEED users who simply highlight the SPEED model of interest and STAR-CCM+ will interpret the data file to create a 3D model ready for simulation. This uses STAR-CCM+’s CAD engine and requires no user interaction. To see a demonstration view the videos listed on the right of this page or contact you CD-adapco contact.

STAR-CCM+ also offers the rapid definition of material properties representing components within your electrical machine. Certain components, such as the conducting wires, if resolved completely increase the overall model size and slow runtime considerably therefore these wires are often resolved as a continuous material with anisotropic properties reflecting the wires conductivity and surrounding insulation. STAR-CCM+ uses CAD feature edges to define the anisotropic normals therefore as electric machine models get more and more complex the set up remains straightforward ensuring an engineers productivity improves. This is a great benefit of having the CAD with the CAE tool.

Future developments focused on electric machines will see the flow and thermal simulations within STAR-CCM+ complimented with solution of the electromagnetic losses within the same code. CD-adapco is ambitiously adding an electromagnetic capability to STAR-CCM+ and this is now available in a 2D form in the current release. Future releases will see SPEED and STAR-CCM+ become ever closer enabling the coupled thermal and electromagnetic effects to be simulated within one code. See the latest webinar for a glimpse of the future, available in the videos section of this page.
STAR-CCM+ in combination with SPEED is an integrated toolset for virtual prototyping of electric machines.

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