With the growth of Additive Manufacturing (AM) technologies, the field of heat exchangers is starting to change. Heat exchangers are used in many industrial applications in different ways, and the industry is always seeking new ways to improve the performance and efficiency of their designs. With the help of metal AM, new design possibilities have emerged, providing freedom on several counts such as complex geometries, weight reductions, less material use and reduced work flow. In this project, a heat exchanger was created following the approach of Design for Additive Manufacturing (DfAM). With extensive research on heat exchanger, DfAM and AM technologies, the aim was to gain a better understanding of the potential of this technology. It was concluded that the design of heat exchangers for AM could be very beneficial for the improvement of performance and the emergence of new design opportunities.

Several iterations were made using the nTopology software. The design explored Triply Periodic Minimal Surfaces (TPMS) structures and followed the project requirements of material, geometry, heat transfer optimisation and 3D printing technology used.

The final model was the summation of the various ideas and lessons learned while working on this project. By ironing out the various shortcomings of the previous iterations, the geometries and functionality converged into this final model. The model incorporates a
diamond TPMS-structure with a 2:1 aspect ratio with a good balance between pressure difference (P) and a relative increase in surface area. The hexagonal outer geometry allows for maximum usage of heat exchanging volume when the modules are working in parallel in a limited space. The modularity of the HexHEX makes the effect of the component scalable by adding several components into a cluster. The parameterised design of the HexHEX allows the customisation of the outer dimensions and length. This is also true for the aspect ratio and the thickness of the TPMS. By designing the component for AM, a minimal amount of supports should be needed for ease of manufacturing and minimising the time required for post-processing.

The model was printed on a Creality Ender 3 in PETG with a 0.2 mm nozzle.

The assessment for the build was realised in Materialise Magics and the model was later printed on a EOS LPBF 3D printer using stainless steel.