Experimental Characterization of a Compact Gyroid-Pipe Heat Exchanger for Fuel Cell Powered Electric Aircraft Propulsion

Abstract

The future of low-emission aviation lies in electric aircraft propulsion systems based on fuel cells. One of the challenge lies in designing and testing critical components, such as heat exchangers, and studying their impact on system-level performance and power densities. This paper presents the design and experimental characterization of a compact TPMS gyroid-pipe heat exchanger with embedded coolant channels. Thermal-hydraulic performance is quantified using heat transfer rate and pressure drop measurements. Three design variants of the gyroid pipe are prototyped and experiments are performed for a range of mass flow rates and temperatures. The results are presented in terms of heat exchanger characteristics and the design operating points are determined. A comparison is made between the gyroid-pipe design and a conventional louvered-fin-plate heat exchanger. The results show that the louvered-fin-plate design outperforms the gyroid pipe design, mainly due to higher pressure loss. Additional design variants of the gyroid pipe heat exchanger, in which the TPMS curvatures are stretched along the air length, improve the thermal and hydraulic performance. The gyroid-pipe heat exchanger design is beneficial as its volumetric and gravimetric power densities are higher than those of a conventional heat exchanger. This is important for reducing the mass of the system and ensuring the feasibility of a fuel cell system in aviation.