What is the Difference Between Altair Flux and FluxMotor?
One of the most common questions from prospects and new users is, what is the difference between Altair Flux and FluxMotor. In this article an introduction to Flux and FluxMotor will be provided and then the difference between the two tools will be compared for different aspects.
Definitions:
Altair Flux is a general finite element (FE) based software for low frequency electromagnetic and thermal simulations. Finite element analysis (FEA) is a popular method for numerically solving differential equations related to modeling an engineering problem. In this method, the geometry is discretized (subdivided) to a finite number of elements (typically called Mesh), a computation is done over each of those elements and then the results are combined for the entire domain. Flux has several modules to model different physical phenomena (magnetic, electric, thermal, thermal coupled) on both 2D and 3D environments. Because of this Flux can be used to model not only electric motors/generators but a wide range of other applications: Actuators, sensors, transformers, induction heating, cables, Medium and high voltage equipment’s…. etc.
Altair FluxMotor is dedicated software for the design, analysis, and optimization of rotating electric motors/generators. It offers an intuitive and easy to use environment to build machines based on standard or customizable parameterized parts, dedicated winding tools, pre-defined set of tests and automated reporting. FluxMotor utilizes a mix of optimization, analytical models, and finite element computation (using Flux as solver) in the background to provides fast and accurate results. It also offers multi-physics capabilities to enable engineers not only to predict the electromagnetic performance of a motor, but also to optimize the cooling strategies and the NVH performance.
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Flux 2D mesh for one pole of PMSM |
An example of FluxMotor parameterized part for inner rotor PMSM |
Type of motors:
From the definition, both Flux and FluxMotor can be used to model electric machines. While Flux offers an open environment suitable to model any type of electric machines in either 2D or 3D environment, the current version of FluxMotor 2022.3 is limited to certain types of three phase radial flux electric machines. This includes:
- Synchronous machine with permanent machines (PMSM) with inner or outer rotor.
- Squirrel cage Induction machine (IM) with inner or outer rotor.
- Reluctance synchronous machines (RSM)
FluxMotor can also consider skewing on the rotor (magnets or bars) or the stator part.
Modeling:
A typical workflow to model an electric machine in Flux involves: Building or importing geometry, meshing, defining physics, solving and post-processing. Although Flux includes motor templates (user overlay) and macros that can help to build some of the steps, it still requires good experience with the tool to set the physics and run the model properly.
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Flux workflow to build the model |
FluxMotor offers an easy and more intuitive workflow to build your motor model. The geometry is defined based on parameters entered by the user based on the specific machine type and template selected. There is no need to define the mesh at all, although it could be controlled through a parameter during the tests. A powerful winding tool to help the user not only to define the winding layout and coils details but it also gives some metrics to evaluate the different layout quickly. The cooling section helps the user define different cooling strategies and check their effect on motor temperature and performance. The material used for the machine can be defined from a set of common predefined materials, but the user can add his own material to the library.
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FluxMotor workflow to build the model |
Type of Analysis:
FluxMotor comes with a list of predefined tests for each type of motor. It includes characterization, working point, performance mapping (efficiency map) and mechanics (NVH) tests. The table below shows a summary of the available tests on FluxMotor 2022.3. Note the thermal and NVH tests are currently available for inner rotor only.
All the tests are very straight forward to set, by providing a set of inputs parameters, and they run quite fast (in matter of minutes). The results are generated automatically for the user to review once the test is done.
Flux provides more open environment that can be used to model any type of basic or advanced tests for electric motors (including all the tests mentioned above, excluding the Mechanics), but it will require more efforts and time to set up the model, solve it and post-process the results. On the other hand, this also means more flexibility in controlling the model and more options on the post-processing of the results.
Although both Flux and FluxMotor can be used for thermal analysis, the method used is different. FluxMotor relies on building a thermal network of the motor to predict the temperature distribution from a set of losses, while Flux uses FE method with forced convection coefficients as boundary condition (it is not fluid dynamic simulation!).
One last important point to mention is that the NVH analysis on FluxMotor relies on analytical modal analysis of the stator part where it is considered as vibrating cylinder. This assumption allows to get fast evaluation of the NVH behavior of the machine, but it is not as accurate as mechanical FEA simulation. If detailed NVH simulation is needed, then it is recommended to use Flux to compute and export the magnetic forces to be used on mechanical FEA tools.
Advice of use:
As discussed above FluxMotor is very easy to use and it provides fast results. That makes it very practical during the design stage, where many ideas and changes can be explored. Also, the ease of use makes it accessible to a broad range of users that are not necessarily experienced with FEA (system engineers, integrators, teachers...etc.).
For more detailed and advanced analysis that are not directly available in FluxMotor, like fault diagnosis, demagnetization, detailed forces, and losses export for NVH and CFD analysis, just to mention a few examples, Flux can be used. However, FluxMotor offers direct connectivity and model export to Flux, which can save the user a lot of time compared to building the model completely in Flux. It is recommended to build the model in FluxMotor and then move to Flux for more detailed analysis, if needed. That is of course only applicable for the machine types that are included in FluxMotor today.
Keep in mind that FluxMotor is relatively new, and it is evolving quickly, and there are a lot of features (including new machine types) that are planned to be added. It is recommended to always check the release notes to be updated about the new features for each release.