The DLR Institute of Electrified Aero Engines is focusing its research on low-emission, electrified propulsion systems for civil transport aircraft. One of the concepts currently being investigated is an all-electric propulsion system based on hydrogen-powered fuel cell systems. Lightweight design solutions for fuel cell system components, in particular for thermal management and its heat exchangers, are essential for the development of a competitive commercial aircraft.
If the optimum operating temperatures of the components are exceeded, the performance, durability and safety of the components may be jeopardised. This can result in limited functionality or even complete failure of the components.
In fuel cell-based aircraft engines, the thermal management system can account for a large portion of the weight and volume of the entire propulsion system. The aim of the research is to increase the power density of the overall propulsion system by developing lightweight, compact heat exchangers.
Triply Periodic Minimal Surfaces (TPMS)
At the Institute of Electrified Aero Engines, we are researching 3D-printed models ofa TPMS (Triply Periodic Minimal Surfaces) cooling structure, which consists of periodically shaped geometries with a very high surface-to-volume ratio.
An additive manufacturing process is well suited to producing such complicated shapes. The fine structure of the object is not a new development by the scientists, but - like many other technical developments - was inspired by nature and can be found, for example, in the wings of insects.
The institute is researching various TPMS geometries with integrated cooling channels. These models are used to experimentally validate complicated and complex calculations on the basis of real component tests. This determines the optimum aerodynamic and thermal performance of the heat exchangers and thus verifies the success of the design.
Innovative Kühlmittelführung
Das Kühlmittel wird in Kreuz- und Gegenrichtung zur Luft durch die Struktur geführt.
The development of compact heat exchangers has reached Technology Readiness Level (TRL) 4 at the Institute of Electrified Aero Engines by validating the concepts under laboratory conditions.
Validation under laboratory conditions
Analyses on the test bench TMT-MAD (Thermal Management Testrig - Modular Air Duct)
