Altair AcuSolve 2024.1 Release Notes

• Battery Thermal Runaway ARC data support
• New Feedback Condition command
• Visualization of heat transfer coefficient through various calculation methods

Battery Thermal Runaway ARC Data Support

Accelerated Rate Calorimetry (ARC) testing is common in the Electrification industry as a means of characterizing a battery cell for thermal runaway simulation. In this version, you have two (2) new options regarding the input and treatment of ARC data. In the first method, you specify Arrhenius equation coefficients that have been extracted following a fit of the ARC data to the Arrhenius equation. The second method reads and applies the ARC data directly to the simulation model. In the fitting approach the ARC data can be split into a maximum of five (5) stages, each fit to a separate Arrhenius equation generally accounting for a specific battery cell component decomposition.

Battery Thermal Third Order ECM

The third-order equivalent circuit model (ECM) represents the battery’s dynamic behavior using three resistor-capacitor pairs. This model has an advantage over lower-order versions by more accurately capturing the battery’s dynamic voltage response.

Feedback Condition Command

A new command, named FEEDBACK_CONDITION, is introduced to allow you to control heat input conditions in the model based on the temperature calculated elsewhere in the model. Currently, point locations are supported for providing the feedback temperature which can control the effect of either surface or volumetric heat flux conditions. Controls involve cutting off the heat input or maintaining a given temperature when the condition is reached.

Visualizing Heat Transfer Coefficient

You have the option to select from three (3) different methods for calculating heat transfer coefficients (HTC). The first and default method leverages the Thermal Law of the Wall to calculate HTC and is equivalent to what has been previously available. The second method, called the Direct method, calculates HTC and reference temperature based on a user-provided y+ value. The third method takes as input from you a constant reference temperature to calculate HTC. In all cases, the distributed values of HTC and reference temperature are available for visualization. The behavior of these methods is consistent with AcuTherm.

Updates to the Element Quality view

The Element Quality view now supports the Quality Index Range (QI Range) legend, in addition to the existing Criteria legend. The QI Range legend enables you to investigate the model with overall element quality categorized as Worst, Fail, Warn, Good and Ideal.

Documentation Additions

• The theory and guidelines for battery thermo-electric solutions have been added to the Training Manual.
• The theory and guidelines for battery thermal runaway have been added to the Training Manual.
• Radiation symmetry setup guidelines have been added to the Training Manual.
• Information about files generated during solving and the file in ACUSIM.DIR has been moved out of the appendix of the Tutorial Manual to the same level as the physics topics in the Training Manual.
• Guidelines for running topology optimization have been added to the Training Manual.
• A section describing the theory behind topology optimization has been added to the Training Manual.
• Information about setting the host name and port number for multi-node AcuSolve/EDEM coupled jobs has been added to the Training Manual.
• A new section for Enclosure radiation has been added to the Training Manual.
• A description of the acuTopoBlock script has been added to the Program Reference Manual.

SimLab-based Tutorial Additions

Two (2) new tutorials for the SimLab CFD user interface have been added. The new tutorials are:

• ACU-T: 7300 / SL-2510 DOE using Altair Inspire, SimLab and HyperStudy
• ACU-T: 7301 / SL-2515 Solution DOE

The following known issues will be addressed in a future release as the performance of the software is continuously improved:

• OSF output for HTC data is not directly available via acuTrans. You may still use AcuTherm to output nodal data.

• A minor correction has been made to the equation for the Haider Levenspiel drag model.
• A correction has been made to the calculation of sphericity for non-spherical drag coefficient models used in the AcuSolve / EDEM coupling.
• An issue with assigning mass flow or average velocity to hemispherical surfaces has been corrected.
• Wedge elements are now supported for topology optimization.