All machines

Natural convection for end winding

While choosing a model, where the end spaces are cooled with natural convection, FluxMotor® model uses quite a low rotor tip speed ratio (a value of 5) to describe the fluid velocity far from the rotating components. This may lead to overestimation of the cooling of the end winding on high-speed machines.

When a tip speed ratio of 5 seems to overestimate the end winding cooling, it is advised to switch to the forced convection mode.

This mode allows forcing some higher tip speed ratios for areas far from the rotor, but reduces the efficiency of the cooling on the end winding.

This model will be improved for future versions.

Transient thermal computations - Displaying of iso-temperatures

In the test "Performance mapping – Sine wave – Motor – Efficiency map", when a cycle is considered with a transient thermal solving, the representation of the temperature iso-values inside the machine can be visualized all along the cycle with an animation.

The animation can run for the axial and radial views. However, both the animations are not well synchronized. Therefore, there can be troubles while using both at the same time.

Modification of units

To take the change of units into account in a test, the user must reopen Motor Factory. The modification is not considered instantaneously in the applications of Altair FluxMotor® like Motor Factory.

Preferences – Beta level mode

In the tab “Advanced settings / Preferences”, Altair® FluxMotor® “User Level” can be: Standard or Beta. By default, the user level is Standard. In Beta level, the entire qualified features are not available for evaluation.

The FluxMotor® Beta level mode allows performing NVH computations for induction machines – Inner rotor. It gives access to the application “Scripting Factory”.

Export a model into Flux® environment with represented elementary wires

  1. Building time of the model in Flux®

    When slots are filled out with a lot of elementary wires, and all the phases need to be represented with solid conductors inside Flux® 2D model, the resulting python file can be very long. Therefore, the process for building the corresponding model into Flux® environment can take a longer time.

Browse function

Sometimes, opening a folder from FluxMotor® applications via browser function requires a longer time (several seconds).

Hairpin architecture

Solving tests or exporting projects to Flux is not allowed when the Hairpin winding is built with two layers. This will be fixed for the next version (FXM-15516).

Export environment – HyperStudy®

  1. New solver script to be registered
    Before starting new studies in Altair® HyperStudy® by using connectors exported from Altair® FluxMotor®, FluxMotor® must be registered as a new solver script in HyperStudy®. This must be defined only while using the coupling for the first time. 


    Connection between Altair® FluxMotor® and Altair® HyperStudy®
    1 Open the area in HyperStudy® to register FluxMotor® 2022.3 script
    2
    Path where FluxMotors.exe must be selected to be registered as a new solver in HyperStudy®.
    Note: FluxMotors.exe with an “s” at the end of FluxMotors.

    This must be defined only when using the coupling for the first time.
    Note: In the version 2022.1 of HyperStudy, the FluxMotor solver script is automatically registered, when the default path installation is selected while installing Flux and FluxMotor.
    Note: The new auto generation of the HyperStudy study in HyperStudy Application (described above) allows to automatically register FluxMotor® as a new solver script in HyperStudy®. If HyperStudy is not installed in the same folder (by default : C:\Program Files\Altair\2022.3\hwdesktop\hst), the path must be defined in the user preferences via the supervisor of FluxMotor (Path to HyperStudy – Needed for HyperStudy export).

  2. New test and connectors for HyperStudy®

    Connectors for coupling FluxMotor® and HyperStudy® are not yet available for the new added tests, like those with transient thermal computations, or the tests for induction machine like the “Characterization – Model – Motor – Scalar” and the “Performance mapping – Sine wave – Motor – Efficiency map scalar”.

  3. Mandatory synchronization between connector and FluxMotor versions

    The connectors used in HyperStudy must be synchronized with the FluxMotor solver version.

    An error message (inside the log files) is generated while performing HyperStudy studies with a connector provided with a former version of FluxMotor solver.

Problems with slot filling

  1. The slot filling is not yet possible with a non-symmetric parallel slot.

  2. When a toothed winding design is considered with rectangular shape wires, the conductor grouping method "horizontal" doesn’t work properly leading to wrong visualization of conductors. In that case, it is recommended to select the conductor grouping method "vertical".

    All works well with circular shape wires

    Example with a toothed winding design (i.e. the coil pitch = 1) and with 2 wires in hand.

    Horizontal filling – wrong visualization, but the total number of wires is right Vertical filling – good visualization

NVH computations - Advice for use

The modal analysis and the radiation efficiency are based on analytical computation, where the stator of the machine is considered as a vibrating cylinder.

The considered cylinder behavior is weighted by the additional masses, like the fins or the winding and the subtractive masses, like the slots and the cooling circuit holes.

This assumption allows getting faster evaluation of the behavior of machine in connection to NVH. But, in no way this can replace a mechanical finite element modeling and simulation.

Possible reasons for deviations of results can be the following ones:
  • The limits of the analytical model are reached or overpassed
  • Unusual topology and/or dimensions of the teeth/slots
  • Complexity of the stator-frame structure when it is composed with several components for instance
  • The ratio between the total length of the frame Lframe and the stack length of the machine Lstk. In any case, this ratio must be lower than 1.5: