SWITCH engine concept combines new technologies

Pratt & Whitney, MTU Aero Engines, GKN Aerospace, Collins Aerospace, and Airbus are joining forces in a consortium to research and develop a new, sustainable and efficient turbofan engine concept that could become available around the mid-2030s. It’s probably not a coincidence that this timeframe matches that of the introduction of the next generation of airliners. SWITCH engine concept combines new technologies.

The companies work together in the SWITCH program, which stands for Sustainable Water Injection Turbofan Comprising Hybrid-Electrics. Already in September, the project was granted co-funding from the European Union’s Clean Aviation program as part of the ultra-efficient propulsion systems sub-category for short- and medium-haul aircraft. The EU has provided €700 million for twenty Clean Aviation

projects. MTU Aero Engines’ Claus Riegler (Senior Vice President Technology & Engineering Advanced Programs) was unwilling to specify how much SWITCH is getting under Clean Aviation Phase 1 (2023-2025). More phases are dependent on the outcome of the initial results.

SWITCH is combining two new technologies that have been studied as part of P&W’s Geared Turbofan (GTF) next-generation research programs. The first is MTU’s Water Enhanced Turbofan (WET), which we discussed extensively on AirInsight in February. WET uses vaporized water that is in the fuel (be it kerosene, sustainable aviation fuel (SAF), or hydrogen), condensate it out of the exhaust gas, recycles it, and reinjects it into the combustor. The water cools and improves the combusting process, reducing nitrogen oxide (NOx) emissions by some 80 percent. MTU provides the steam turbine and water recovery unit, Collins the condenser, P&W the steam-injecting combustor, and GKN Aerospace the vaporizer. Pratt admits that there are some similarities between WET and the US-funded HySIITE program, but this is fully focused on using hydrogen, said Graham Webb, Chief Sustainability Officer, in a joint presentation to media.