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.

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Bjorn’s Corner: Why e in ePlane shall stand for environment, Part 13. Serial Hybrid.

March 13, 2020, ©. Leeham News: In this week’s Corner, we address an often forgotten aspect of Electric and Electric-Hybrid aircraft design.

The battery as an energy source, as the only or assisting source, has the same weight during the whole flight. A fuel (alternate, fossil, or hydrogen) consumes during the flight. You gradually fly a lighter aircraft. Let’s see how this affects the aircraft’s efficiency.

Figure 1. Embraer’s E175-E2, a latest-generation 88 seater jet used for our example. Source: Embraer.

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Bjorn’s Corner: Why e in ePlane shall stand for environment, Part 12. Battery risks.

March 6, 2020, ©. Leeham News: We use this week’s Corner to discuss the safety hazards a change to an Electric or Hybrid-Electric airliner introduces.

The trigger is two battery fires in six weeks for the electric aircraft prototypes which are now flooding the market.

Figure 1. Eviation’s Alice battery-driven prototype. Source: Eviation

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Bjorn’s Corner: Why e in ePlane shall stand for environment, Part 7. Efficiency of cars versus airliners.

January 31, 2020, ©. Leeham News: We now look at ways to increase the fuel efficiency of our airliner and by it, improve the CO2 situation for our environment.

Let’s start with understanding where we are with the efficiency of our present air transport system. To get a feel for where we are we will compare it to our road transport system.

Figure 1. A principal view of a two-spool airliner turbofan. Source: Wikipedia.

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Bjorn’s Corner: Why e in ePlane shall stand for environment. Part 1. Hype versus reality.

December 13, 2019, ©. Leeham News: The first all-electric commercial aircraft, a Harbor Air DHC-2 Beaver, flew over the Fraser River near Vancouver in the week (Figure 1). It was powered by a magniX electric engine fed with energy from batteries.

Despite this progress, this Corner series is about why the e in our future ePlanes should stand for environment and not electric.

Figure 1. Harbour Air seaplane flying with a magniX electric engine feed by batteries. Source: magniX.

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Electric aircraft builder announces new engine option

By Bryan Corliss

April 22, 2019, © Leeham News:  Electric aircraft motor builder MagniX will celebrate Earth Day today by announcing it has been chosen as one of two powerplants for Eviation Aircraft’s proposed nine-seater Alice passenger plane.

“We have been successfully testing the MagniX system with our Alice aircraft propeller for quite some time now with great results,” Eviation Chief Executive Omer Bar-Yohay said in a statement.

The MagniX motor has more than 1,500 hours on a test stand, according to Roei Ganzarski, who is CEO of the suburban Seattle engine-builder.

The Alice is a clean-sheet electric aircraft design developed by Eviation, an Israeli company that has established a testing/production facility in Prescott, AZ. Eviation has announced plans to fly the Alice at Le Bourget this summer.

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Bjorn’s Corner: Electric aircraft, Part 13

By Bjorn Fehrm

September 22, 2017, ©. Leeham Co: After 12 articles about electric aircraft, it’s time to wrap up. We will go through what we have learned and discuss future developments.

Our designs were aimed for the next decade and the result was sobering. Electric aircraft have important challenges to traverse. As had electric cars, and they have turned the corner.

Figure 1. Idea for future aircraft that could use electric propulsors. Source: NASA.

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IATA on air safety

By Bjorn Fehrm in Dublin

June 1, 2016, ©. Leeham Co: We report from the International Air Transport Association’s (IATA) Annual General Meeting running in Dublin Thursday and Friday this week, where all the world’s airlines meet to report on a number of initiatives and decide on things to do going forward.

The first briefing from IATA was on the level of safety in the air for 2015, measured through the IATA Operational Safety Audit, IOSA. 2015 was a good year, not quite to the level of 2014 which was the safest year in history, but close at 0.32 jet hull losses per one million flights instead of 0.27 recorded for 2014, Figure 1.

Figure 1. Jet hull losses during 2015 per million flight hours. Source: IATA.

As a reference, the the 2013 rate was 0.41 hull losses over one million flights. The 2015 rate was a 30% improvement over the average rate of the years 2010-2014. The turboprop level was worse at 1.29 hull losses per million flights but it was a large improvement compared to previous years at 3.13 and 3.95. It shall be cautioned that the sample size for Turboprops is much smaller than for Jets, therefore one hull loss will affect the statistics quite a lot. Read more

Bjorn’s Corner: Electrical flight, how real?

By Bjorn Fehrm

By Bjorn Fehrm

10 July 2015, ©. Leeham Co: We have just witnessed the first solar electrical aircraft, Solar Impulse 2, cross the ocean from Tokyo to Hawaii. Today, Friday, Airbus Group will cross the English Channel with a battery powered electrical aircraft, the E-Fan.

How real is electrical flying? Real enough to make demonstration flights like the one to Hawaii and to Calais. Both these aircraft are technology demonstrators but it is symptomatic that they do these hops now, 2015.E-Fan cross Channel

Airbus Group’s E-Fan aircraft is preparing to cross the English Channel. Source: Airbus.

We live in the years when electrical cars have gone from exotic one-offs to serial produced products, still expensive but more and more practical. Why should not the aircraft industry follow? Read more

PNAA Conference Pt 3: Renewable biofuels

The future of bio-fuel is different from the bio-fuel today, says John Plaza, CEO of Imperium Renewables. He is speaking at the Pacific Northwest Aerospace Alliance conference in suburban Seattle. It will be drop-in fuel, potential to be cheaper, meet same specifications as petroleum, equivalent to civilian (JP-8) and military fleets (JP-10).

First generation of bio-fuel is bio-diesel. Second generation will be the drop-in described above. Bio-fuels have to become multiple products as in the petroleum industry.

  • We’re seeing increasing density of bio-fuels, which increases BTUs and efficiency on long-haul flights.
  • WA State has one of highest recycling programs in the country but still generates a lot of trash (much of which is trained to Oregon). Trash can contribute to bio-fuel.
  • Bio-fuel without subsidy costs around $4/gal vs $3.25 or so for jet fuel, so there is still a price disparity.
  • 200 million gallons of jet fuel within 100 mile radius of wood slash can be generated.
  • Other feed stocks: Jatropha, Eucalyptus, mixed growth plots. Algae is interesting but requires more research.