Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- Boeing defends 787, 777 against whistleblower charges April 17, 2024
- Dissecting Boeing CEO’s statement next new airplane will cost $50bn April 15, 2024
- Bjorn’s Corner: New engine development. Part 3. Propulsive efficiency April 12, 2024
- A350-1000 or 777-9? Part 2 April 11, 2024
- Pontifications: Boeing “transparency”–not so much. April 9, 2024
Bjorn’s Corner: The challenges of Hydrogen. Part 9. Hydrogen Gas Turbines
September 18, 2020, ©. Leeham News: In our series on hydrogen as an energy store for airliners we analyze the conversion of the present Turbofan and Turboprop airliner engines to hydrogen as fuel instead of carbon-based fuels.
We know it’s possible as the world’s first jet engine from 1937 ran on hydrogen, Figure 1. But what are the problems and how good are the hydrogen-fueled engines in efficiency and emissions?
Figure 1. The world’s first jet engine, Hans von Ohain’s He S-1. The engine’s aerodynamics is pictured below the cut-through. Note the skewed hydrogen injector at c. Source: Wikipedia.
Bjorn’s Corner: The challenges of Hydrogen. Part 8. Fuel cell electric or Turbofan propulsion?
September 11, 2020, ©. Leeham News: In our series on Hydrogen as an energy store for airliners we look at whether we use an LH2 burning Turbofan as propulsion or as the EU study proposed, a Parallel Hybrid feed by a fuel cell, Figure 1.
Figure 1. The Parallel Hybrid 165 seat aircraft from the EU Hydrogen study. Source: EU.
Bjorn’s Corner: The challenges of Hydrogen. Part 7. The fuel system.
September 4, 2020, ©. Leeham News: In our series on Hydrogen as an energy store for airliners we look at the rest of the fuel system after we looked at the hydrogen tanks over the last weeks.
The cryogenic state of the liquid hydrogen (cryogenic=very low temperatures, -253°C) creates some new challenges when designing the fuel system.
Figure 1. The Tu-155 Hydrogen research aircraft with its aft fuselage tank and fuel system. Source: Tupolev.
Bjorn’s Corner: The challenges of Hydrogen. Part 6. Tank placement.
August 28, 2020, ©. Leeham News: In our series on Hydrogen as an energy store for airliners we look at the challenge of placing the hydrogen tanks efficiently.
Different from carbon fuels, liquid hydrogen needs specially shaped and bulky tanks. It can’t be stored in the wingbox as today’s Jet-A1.
Figure 1. The Tu-155 Hydrogen research aircraft with its aft fuselage tank. Source: Tupolev.
Bjorn’s Corner: The challenges of Hydrogen. Part 5. The Hydrogen tank.
By Bjorn Fehrm
August 21, 2020, ©. Leeham News: In our series on hydrogen as an energy store for airliners we start the design discussion of a hydrogen-fueled airliner by understanding the onboard storage of hydrogen better.
While there is present knowledge from for instance the space launcher industry, the storage demands for launchers are hours rather than days. Several implementations of longer storage aeronautical tanks have been done, among others by NASA/Boeing for high flying UAVs.
Airbus and the Russian aircraft industry were also active with research during the 1990s and Tupolev built a test aircraft that included a complete hydrogen fuel system (Figure 1).
Figure 1. The Tu-155 Hydrogen research aircraft. Source: Tupolev.
Bjorn’s Corner: The challenges of Hydrogen. Part 4. Hydrogen safety.
By Bjorn Fehrm
August 14, 2020, ©. Leeham News: In our series on hydrogen as an energy store for airliners we are closing in on the design problems for a hydrogen-fueled airliner.
One of the aspects we must understand before discussion aircraft solutions are the safety aspects of hydrogen as a fuel in aircraft. Another is the requirements for the storage of liquid hydrogen, LH2.
Figure 1. The Hindenburg disaster at Lakehurst in May 1937. Source: Wikipedia.
Bjorn’s Corner: The challenges of Hydrogen. Part 3. Application space.
By Bjorn Fehrm
August 7, 2020, ©. Leeham News: In our series on Hydrogen as an energy store for airliners we now look at the emission targets one is chasing and then discuss for what type of airliner does a hydrogen propulsion system make sense.
The CO2 emission target as expressed by Air Transport Target Group (ATAG) is shown in Figure 1. The graph is from the EU report on Hydrogen Powered Aviation.
Figure 1. The development of CO2 from aviation and the ATAG 2050 target. Source: EU Hydrogen Powered Aviation report.
Bjorn’s Corner: The challenges of Hydrogen. Part 1. Background.
By Bjorn Fehrm
July 24, 2020, ©. Leeham News: What a difference three months make!
When I wrapped the 20 piece Corner series about e in ePlane not standing for electric, on the first of May, I was virtually alone in saying hydrogen is the best long term alternative to our airliners’ jet fuel.
Today it’s all about hydrogen, especially if you ask industry and authorities in Europe. What happened?
Figure 1. The Russian Tu-155 hydrogen fuel research aircraft that flew in 1988. Source: Tupolev.
Bjorn’s Corner: Do I get COVID in airline cabins? Part 11. Wrapup.
By Bjorn Fehrm
July 18, 2020, ©. Leeham News: It’s time to wrap our Corner series about flying during the COVID-19 pandemic.
We started the series on the 8th of May. A lot of knowledge has been gained since, about COVID-19 in general and when taking a scheduled flight.
Figure 1. The difference of coughing without and with a mask. Source: Simulations by Florida Atlantic University, composited and annotated by LNA.
Bjorn’s Corner: Do I get COVID in airline cabins? Part 10. Trans-Atlantic trip.
By Vincent Valery
July 10th, 2020, © Leeham News: In our Corner series about flying during the COVID-19 pandemic, we look at a trip undertaken last week by a member of the LNA team, Vincent Valery. Vincent, who flew from New York to visit family in France close to Geneva, writes this post.
On the flight over the Atlantic in Economy. Source: All photos LNA.