Thermo-mechanical performance evaluation of a gyroid TPMS heat exchanger manufactured by metal additive manufacturing

Abstract

Developments in additive manufacturing have enabled engineers to produce intricate geometries that can be used for the development of heat exchanger systems. Heat exchangers (HX) are widely used in several applications, and the demand for energy-efficient systems has increased the growth in research of compact high-performance heat exchangers. This study evaluates thermo-hydraulic and structural performance of a gyroid-based lattice heat exchanger manufactured from AISI 316L stainless steel via laser powder-bed fusion against a conventional fin-tube design. Steady state numerical analysis was performed by varying the velocity to obtain temperature changes (ΔT) at outlets, pressure drop characteristics (ΔP) and analyzing heat-transfer behavior. Corresponding finite element simulations were performed using pressure fields from fluid analysis to determine the deformation (Δ l) and the maximum principal stress in the heat exchanger cores.

Initially, lattice HX performed 31% better than fin-tube HX in terms of outlet fluid temperature; however, at higher velocities the pressure drop in lattice HX was 16 % more compared to the baseline model. Accounting for the increased pumping power due to pressure drop was done by calculating the performance evaluation criterion (PEC). Maximum principal stress at 1200 Pa was 8.1 MPa and 12 MPa for lattice and baseline models, respectively. Total deformation in the lattice HX core was 6x10^-4 mm compared to 8x10^-4 mm of fin-tube HX. Overall, the results demonstrate that additively manufactured gyroid heat exchangers offer a substantial advantage in thermal effectiveness, flow mixing, and uniform load distribution, supporting their use in compact and efficient heat management systems.