Enhancement of heat exchanger performance using additive manufacturing of gyroid lattice structures

The main objective of this research is to investigate the capability of laser powder bed fusion (LPBF) to manufacture complex heat exchangers with gyroid-shaped channels. First, the gyroid’s geometric features are investigated including the network type, thickness, unit cell size, and aspect ratio. Computational fluid dynamics (CFD) were used to screen these designs based on their thermal and fluid dynamics performance. Then, the manufacturability of various AlSi10Mg gyroid designs is tested using the LPBF, and the microstructure was investigated for defects. Finally, five heat exchanger prototypes were manufactured using LPBF; four of them were based on gyroid designs, and the fifth one was a conventional design for comparison. A heat transfer analysis is performed to compare the performance of the heat exchangers using conjugate heat transfer (CHT) methods. It was found that manipulating the sheet gyroid thickness and aspect ratio can result in a reasonable tradeoff between air side and coolant side pressure drops while maintaining the same heat rejection value. The suggested process parameters were able to successfully print the gyroid heat exchanger cores with thicknesses higher than 0.2 mm successfully. The LPBF-fabricated gyroid heat exchangers outperformed the conventional design. This study paves the road to a new generation of crossflow heat exchanger designs.