The TRIATHLON project containts four technical workpackages (WP): WP1 Hydrogen Conditioning Requirements, WP2 Thermodynamics Controlled Storage, WP3 Thermal Management and Thermondynamic Performance and WP4 System-Level Analysis and Technology Roadmap.
After an extensive literature review, it was decided to focus on High Temperature Proton Exchange Membrane fuel cells (HT-PEMFC) in WP1. High-fidelity Ansys Fluent simulations were compared with validations found in literature. Based on the results, it was decided to focus on thermal power dissipation to the environment. It was considered where power should be rejected to the environment of the aircraft, and a choice was made for the underfloor bay. Work is on-going regarding the CFD characterization of the HT-PEMFC heat-rejection environment, as well as the synergies between powertrain components needing to receive or reject heat respectively.
Simultaneously, a reference combustion system for WP1 was found in the FlyECO concept design. High-fidelity simulations employing the in-house OpenFOAM tFDF-ESF solver of TU Delft, were performed with the objective to optimize the combustor design. The first results are promising in terms of NOx reduction, but further optimization is needed. Water injection could help with this.
In WP2, a generic tank sizing tool was developed and validated. Two reference flight profiles for a megawatt-class aircraft were selected: ATR 72-600 and Novacom. The storage size for a cryo-compressed storage tank and subsequent hydrogen mass flows for the respective flight profiles were estimated and the ensuing thermodynamic performance of the storage tank was analyzed. Simultaneously a new approach to high-fidelity damage modelling of a fully composite pressure tank has been developed to predict crack formation in the laminate, which can then be linked to permeability of the tank wall. A new test rig for permeation tests of the composite tank wall was developed as well.
In WP3 ceramic coupons with different materials and geometric properties were 3D printed. A numerical analysis was made of the expected flow through the coupons at different Reynolds numbers, as well as the expected thermal behaviour. A test-rig to perform the single- and two-phase experiments was developed and the first set of experiments on this test-rig has almost been completed. The results will be used for the production of a second batch of coupons.
In WP4 a literature and market review of hydrogen powertrains for megawatt class aircraft have been performed. Next to that, a model of the entire powertrain has been created using Matlab and Simulink, effectively combining the other three technical work packages. And a beginning of a technology roadmap has been made, to predict future developments needed to bring the technology developed in TRIATHLON to fruition.
