May 2025 critical fixes

May 2025 fixes were published on 15 May 2025.

Bug 62464: Improve the distribution of emitted rays on skewed quadrilateral elements for GPU radiation calculation methods

Fixed versions: 2512.0

In GPU radiation calculations, quadrilateral elements are divided into two triangles. When a quadrilateral element is skewed, the resulting triangles may exhibit significantly different areas. Assigning an equal number of rays to each triangle can lead to biased results favoring the smaller triangle. To address this, the distribution of rays is now weighted according to the area of each triangle.

Bug 97627: Thermal solver assumes conduction for thermo-mechanical contact, even if the two regions become significantly distant due to structural movements

Fixed versions: 2512.0

Previously, elements within contact regions that became disconnected due to structural movements were still treated as if they were in contact by the thermal solver. Now, these elements are accurately identified as non-contacting, resulting in a heat transfer coefficient of zero in the post-processing results.

Bug 103640: Incorrect total heat flux results are produced for finite element models when a heat load is applied to the edge of a plane stress mesh with multiple instances defined

Fixed versions: 2506.0, 2412.8, 2406.12

The thermal solver incorrectly calculated total heat flux results when heat loads were applied to the edges of plane stress elements in finite element models. This error occurred due to the omission of the number of instances in the calculations. The recent fix now appropriately accounts for the number of instances in these elements.

Bug 106512: Incorrect temperatures are computed for models with simple radiation to environment applied to the edges of chocking meshes for any gap thickness defined

Fixed versions: 2506.0, 2412.8, 2406.12

Models that included simple radiation to environment requests applied to the edges of chocking elements generated inaccurate temperature results, irrespective of the gap thickness defined. The solver’s methodology for treating this scenario was flawed. This issue has now been corrected.

Bug 106698: Provide accurate heat flow calculations in the .bcdata summary file for convection coupling and thermal stream boundary conditions using the relative temperature reference frame option

Fixed versions: 2506.0, 2412.8

The heat flow reported in the .bcdata summary file was inaccurately computed for convection coupling boundary conditions when rotational effects were present, specifically with the relative temperature reference frame. Additionally, the heat flow computed for thermal streams (CHR/THR) and recorded in the same file showed discrepancies compared to the expected theoretical values when the relative temperature reference frame option was selected. A correction has been made in the thermal solver, affecting only the post-processing of convective heat flow results in the .bcdata summary file.

User Story 107817: Provide more informative messages when the system's GPU card is not supported for GPU computed ray tracing and GPU computed view factors calculation methods

Fixed versions: 2512.0, 2506.1, 2412.9

When using GPU calculation methods to solve radiation models, the thermal solver is compatible with NVIDIA GPUs featuring Pascal or newer microarchitectures, with compute capabilities ranging from 5.0 to 9.0a. With this update, the thermal solver detects unsupported GPUs and provides fatal error messages to inform the user.

Bug 107988: Incorrect temperatures are computed for models with convective or radiative couplings applied to the edges of chocking meshes when the number of gaps exceeded one for variable gap thickness

Fixed versions: 2506.0, 2412.9, 2406.13

Models that included convective or radiative couplings applied to the edges of chocking elements generated inaccurate temperature results when the specified number of gaps exceeded one. The thermal solver did not properly account for the number of gaps if the gap thickness was defined in mesh associated data. This issue has now been corrected.

Task 107877: Using the Functional Mock-up Interface (FMI) standard, retrieve initial conditions from the external solver and update the values in the thermal solver

Fixed versions: 2512.0

For co-simulation models, initial conditions from the external solver were previously set to zero. The initial values are now correctly retrieved and updated in the thermal solver for both FMI 2.0 and FMI 3.0 standards.