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Engineering an Aircraft Hydrogen Powertrain

  • Magazine Article
  • 21AERP06_03
Published June 01, 2021 by SAE International in United States
  • English

ZeroAvia's journey into the world of the hydrogen powertrain began with a mission to decarbonize one of the most challenging sectors in existence due to the complexities in recreating the synthesis of chain reactions that aircraft require to fly securely with hydrogen fueling. Currently, the balance of engine-triggered events that power, heat, pressurize, and so forth is not necessarily the result of the high-efficiency performance of fossil fuels. Yet, aircraft use engine inefficiencies to fill other needs such as thermal management. One of the most significant challenges in designing an effective hydrogen powertrain system is keeping the aircraft capabilities intact by using efficient and non-efficient fossil-fuel turbine engine performance metrics as a benchmarking tool for peak hydrogen performance.

As a physicist and pilot (both fixed-wing and helicopter), I started ZeroAvia because I wanted to work with engineers to move the needle towards zero-carbon aviation. To do this, we needed to target a significant existing segment. That means relatively larger aircraft (10-20 seats) for a relatively long distance (500 miles). The most practical way to do this anytime soon is via hydrogen fuel cells, which are currently about four-times more energy-dense than the best available batteries, even with compressed gas hydrogen storage. Liquid hydrogen brings about a two to three times increase in energy density, which is close to the density of jet fuel. In five years, ZeroAvia expects liquid hydrogen storage to become safety-qualified in aircraft, allowing achievement of 1,000+ mile ranges in even larger aircraft.