Leeham News and Analysis
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Bjorn’s Corner: Sustainable Air Transport. Part 18. Advanced Hydrogen Gas Turbines
By Bjorn Fehrm
May 6, 2022, ©. Leeham News: Last week, we looked at how we create the shaft power for the thrust device we discussed before. We described the basics of a hydrogen-burning gas turbine alternative.
When we have liquid hydrogen as fuel, several advanced developments are possible. It’s what we look at now.
Figure 1. Airbus ZEROe hydrogen gas turbine concepts. Source: Airbus.
Bjorn’s Corner: Sustainable Air Transport. Part 17. Gas Turbine Propulsion
By Bjorn Fehrm
April 29, 2022, ©. Leeham News: Last week, we looked at the thrust generating device that aircraft propulsion systems use. We could conclude that independent of how we create the shaft power, we can choose different thrust technologies with desired characteristics. A propeller, open fan, or fan in nacelle covers different speed ranges and efficiency profiles.
Now we look at how we generate the shaft power for these devices. We start with the hydrogen-burning gas turbine alternative.
Figure 1. Airbus ZEROe hydrogen gas turbine turboprop concept. Source: Airbus.
Bjorn’s Corner: Sustainable Air Transport. Part 15. Hydrogen propulsion system choices.
By Bjorn Fehrm
April 15, 2022, ©. Leeham News: Last week, we examined different airliner types’ power requirements and the importance of their size classes in the market.
Now we look at what propulsion system alternatives are available when using hydrogen as the energy source and their principal advantages and disadvantages.
Figure 1. CO2 emission by airliner segments. Source: EU Hydrogen-powered aviation report.
Bjorn’s Corner: Sustainable Air Transport. Part 14. Propulsion system requirements.
By Bjorn Fehrm
April 8, 2022, ©. Leeham News: Last week, we discussed the architecture of a liquid hydrogen fuel system. We now start looking at the propulsion system of a hydrogen aircraft.
Before discussing how a propulsion system is done, we must understand what power requirements different airliner types have and the importance of these types in the market.
Figure 1. The World Jet market forecast for the next 20 years. Source: JADC.
Bjorn’s Corner: Sustainable Air Transport. Part 13. Hydrogen fuel system and APU.
By Bjorn Fehrm
April 1, 2022, ©. Leeham News: Last week, we looked at how to store hydrogen in an aircraft. We could see the gaseous storage of hydrogen is too heavy other than for demo systems and extreme short-haul. For practical airliners, liquid hydrogen is the solution.
Now we look at what this means for the aircraft fuel system and how to configure a suitable Auxiliary Power Unit, APU.
Figure 1. Typical placement of hydrogen tanks. Source: Leeham Co.
Bjorn’s Corner: Sustainable Air Transport. Part 12. Hydrogen storage.
By Bjorn Fehrm
March 25, 2022, ©. Leeham News: Last week, we looked at the energy density by mass and volume for hydrogen and regular Jet fuel (Kerosene), Figure 1.
With this information, we now look at how these fuels can be stored in an aircraft.
Figure 1. The Volume and Mass densities of fuels. Source: Boeing.
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Bjorn’s Corner: Sustainable Air Transport. Part 11. Hydrogen and SAF.
By Bjorn Fehrm
March 18, 2022, ©. Leeham News: In our series, we have now seen the major limitations batteries as an energy source impose on an airliner and that hybrids work but don’t bring any advantages for an airliner.
The alternatives are to use an energy source with a higher energy density and combine it with an efficient propulsion system. Sustainable Aviation Fuel, SAF, has the same high energy density as today’s Jet fuel and hydrogen’s density is three times higher than Jet fuel.
Figure 1. The Volume and Mass densities of fuels. Source: Boeing.
Bjorn’s Corner: Sustainable Air Transport. Part 6P. Energy consumption, the deeper discussion.
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By Bjorn Fehrm
February 11, 2022, ©. Leeham News: This is a complementary article to Part 6. Energy consumption. It uses the Aircraft Performance Model from our Consultancy practice to generate energy consumed data when we fly a typical airline mission for the first aircraft we analyze, the battery-based Eviation Alice and Heart Aerospace ES-19.
These represent what to expect for airliners that have chosen this energy storage principle.
Heart Aerospace ES-19. Source: Heart Aerospace.
Bjorn’s Corner: Sustainable Air Transport. Part 6. Energy consumption.
By Bjorn Fehrm
February 11, 2022, ©. Leeham News: In a sister article, Part 6P. Energy consumption, the deeper discussion we use Leeham’s Aircraft Performance Model from our consulting practice to generate the aeronautical energy consumption for aircraft like Eviation’s Alice and Heart Aerospace’s ES-19.
This is the energy needed to combat the drag of the airframe during flight (Figure 1). We then add the losses in the chosen propulsion system to arrive at the energy drawn from the energy source.
Figure 1. Simplified force model for an aircraft. Source; Leeham Co.
Airbus readies hydrogen-powered demo flights
Update, Feb. 21: Airbus announced today a press conference tomorrow in Toulouse.
By Scott Hamilton
One concept of where hydrogen tanks could be located.
Feb. 8, 2022, (c) Leeham News: Airbus plans to fly a hydrogen-fueled ZEROe demonstrator soon, with an announcement coming as early as this month.
Airbus’ drive to reduce emissions appears prioritized toward developing an H2-fueled airplane. While all it’s A-Series aircraft will be 100% compatible with Sustainable Aviation Fuel (SAF) by 2030—they’re 50% compatible today—hydrogen is at the forefront of its research and development. Officials want to have an H2-powered airplane ready for service by 2035. This aircraft will almost certainly be a turboprop.
Amanda Simpson, vice president for research and technology of Airbus, said the company must have a demonstration project proving the feasibility of an H2-fueled airplane before full development can proceed. She told the audience at the annual conference of the Pacific Northwest Aerospace Alliance yesterday that an announcement could come within two weeks. In sideline remarks, she declined to say what type of aircraft will be used for the demo project.