October 17, 2023 | WotAn

New combustors for direct hydrogen combustion

Test of a three-sector combustion chamber
Satisfied project participants after the successful 3-sector rig test with different hydrogen nozzles at the project team of the DLR Institute of Propulsion Technology and Rolls-Royce Germany.

Hydrogen-powered aircraft gas turbines have the potential to revolutionize aviation, as hydrogen as an energy carrier significantly reduces the environmentally harmful non-CO2 effects and does not produce CO2 in the first place. However, in order for passenger aircraft to take off with hydrogen power in the future, today's gas turbines need to be modified in a number of ways. The combustion chamber, in which the hydrogen is burned and converted into heat energy, plays a central role in engine technology. The Institute of Propulsion Technology at the German Aerospace Center (DLR) and Rolls-Royce Deutschland are working together on a new combustor technology for future aircraft engines in which hydrogen is burned directly. The WotAn project (for Hydrogen Combustion Technology for New Generation Propulsion Systems) is funded by the German Federal Ministry of Economics and Climate Protection (BMWK).

Neue Brennkammern für Wasserstoffdirektverbrennung
In einer gemeinsamen Messkampagne haben das DLR und Rolls-Royce Deutschland zum ersten Mal verschiedene Wasserstoff-Brenner in einer Drei-Sektor-Brennkammer am Hochdruck-Brennkammer-Prüfstand 1 am DLR-Institut für Antriebstechnik in Köln bei realistischen Betriebsbedingungen getestet.

New combustion chamber concepts have to be adapted to the special combustion properties of hydrogen. Based on previous computer flow simulations, DLR and Rolls-Royce are designing new burners and combustor concepts and characterizing their performance on DLR's high-pressure combustor test benches in Cologne. "For this purpose, we have upgraded two of our combustion test benches at the Institute of Propulsion Technology in Cologne for the combustion of hydrogen," explains DLR's Dr Thomas Behrendt. "The highlight of both high-pressure test benches is their optical access. Through these quartz glass windows, we can characterize the combustion without contact using advanced laser measurement technology and generate unique data sets on combustion behaviour".

Milestone: Three-sector combustion chamber tested

In the current joint measurement campaign, DLR and Rolls-Royce Deutschland have for the first time tested various hydrogen burners in a three-sector combustion chamber under realistic operating conditions at DLR's High Pressure Combustion Chamber Test Stand 1 (HBK1) in Cologne. Project manager Dr Carsten Clemen from Rolls-Royce Deutschland is satisfied: "This 3-sector rig test with different hydrogen nozzles in the HBK1 test stand under realistic engine conditions is a milestone on the way to implementing such a nozzle in a modern Rolls-Royce aero engine. This was achieved in just 22 months. The excellent cooperation with our partner DLR in the LuFo WotAn project enabled us to carry out the first atmospheric single-sector tests at DLR by the end of the first year of the project, and now we are able to obtain data under high-pressure conditions on the optical triple-sector rig, which allows us to release the hardware for testing in an engine combustor on the high-pressure combustor 5 full-ring test stand.

The tests at DLR's High Pressure Combustion Chamber Test Stand 5 in Cologne are planned as part of the EU Cavendish project.