The project undertaken by DHCAE Tools GmbH, in partnership with Otto Fuchs, produced a fully digital representation of the heat‑treatment process for titanium components. The aim was to identify the influence of heat transport on the overall process, to develop computer‑based optimisation strategies, and to incorporate the coupled interaction between fluid flow, heat transfer and structural deformation into a single, automated workflow. The final deliverable was a validated, coupled CFD/CSM simulation framework that can be used in product development to predict distortion during heat treatment.
The technical work began with the acquisition of experimental data on the cooling behaviour of titanium parts by Otto Fuchs. These measurements were used to calibrate and validate the numerical model. DHCAE Tools performed the CFD modelling with the open‑source solver OpenFOAM, creating a detailed mesh that captured the geometry of the component, its supports and the surrounding air. Particular attention was paid to the narrow gaps between the supports and the part, which can severely affect heat conduction and mesh quality. The team investigated the impact of these gaps on the simulation results and discussed the findings with the experimental partner. The structural analysis was carried out with CalculiX, another open‑source solver, allowing the transfer of temperature fields from the CFD simulation to the structural model. This one‑way coupling enabled the prediction of thermal strains and resulting distortions.
During the development of the coupled model, several performance aspects were addressed. The mesh generation strategy was optimised to avoid highly distorted cells in the narrow support gaps, which previously caused convergence problems or solver crashes. By refining the mesh in critical regions and applying appropriate boundary conditions, the solver achieved stable convergence for the transient heat‑transfer calculations. The coupled simulation was then compared to the experimental cooling curves; the temperature evolution predicted by the model matched the measured data within a few degrees Celsius, demonstrating the validity of the approach. The structural predictions of distortion were also in good agreement with the experimental measurements, confirming that the coupled CFD/CSM framework can reliably forecast the final shape of the component after heat treatment.
Beyond the scientific results, the project delivered an automated workflow that integrates the CFD and structural solvers, mesh generation, simulation execution and result post‑processing. DHCAE Tools developed GUI‑based tools for mesh creation and monitoring of simulation runs, and extended an existing monitoring tool to provide real‑time feedback on solver performance. The workflow was tested on the titanium part and can be reused for other heat‑treatment projects, such as aluminium casting, where DHCAE has already delivered cooling‑time models.
Collaboration was central to the project. DHCAE Tools handled the numerical modelling, workflow automation and training of the partner’s staff. Otto Fuchs performed the experimental measurements, supplied the CAD geometry, and applied the simulation methods to their production process. The project was funded under the SimTiPro programme (grant number 03LB1007B) and ran until the report date of 23 October 2023. Additional discussions were held with the Institute of Technology and Work (IWT) Bremen and with Prof. Kraska from Brandenburg to evaluate the suitability of the open‑source solver CalculiX for creep analysis, further extending the scientific scope of the collaboration. The combined effort produced a robust, validated simulation tool that bridges fluid dynamics, heat transfer and structural mechanics for titanium heat‑treatment, and establishes a foundation for future industrial applications.