Towing petroleum from Australia – NRC

“The steamer is back,” said one enthusiastic co-editor. He sent a press release as proof. But that was it wishful thinking: Pratt & Whitney develops aircraft engines that burn hydrogen and use steam injection to increase efficiency and reduce NOxxto reduce emissions. Injection of homemade steam. The futuristic engine is a turbine, not a steam engine.

Which does not change the fact that there were steam planes. In April 1933, a biplane equipped with a steam engine of the kind that had driven heavy vehicles since 1903 took off over California. The water in the boiler was heated by burning petroleum, the steam again turned into water in a condenser. The machine ran largely silently, but was complex and heavy (240 kg) and less efficient than explosion engines. No salvation can be expected upon reintroduction.

Everyone knows that salvation must come from electric flight. Electric planes were there early too. In October 1973, a modified aircraft equipped with NiCad batteries could hold a person in the air for nine minutes, writes Wikipedia. Since then, progress has been sparse. The whole of the Netherlands is waiting for planes that can be flown to Portugal and Turkey without shame, but we will have to wait at least three decades longer. It was elected in 2019 to Natural energy

Miserable energy density

The difficulty lies in the miserable energy density of lithium batteries. At best, it is 0.25 kWh per. kg and in a practical setup it is only 0.20 kWh / kg. That’s just 1.7 percent of petroleum’s energy content. If the energy density of the batteries were to increase by 4 percent annually, the density would have doubled in 18 years. But only when the content is quadrupled it is possible to fly to Paris electrically, and even then it is a bit of a tick.

the piece in Natural energy was enlightening. It was determined that flying fully electric in the United States reduces CO2emissions from air traffic currently would enlarge, given the unfavorable fuel distribution of the US factories. Fully electric flying is also not without sound: electric propeller propellers make a lot of noise.

For now, we are left with the miserable flight shame, even though no airlines care about it. And certainly not the Australian company Qantas. It announced in early May that it would offer non-stop flights from Sydney to London from 2025, 20-hour non-stop flights to refuel and recover.

No stopovers

There has been a non-stop connection between London and Perth in northwestern Australia since 2018, but the distance to Sydney is greater, around 17,000km. In recent decades, one or two stopovers were usually made on the journey: in Singapore and / or Bahrain (or Dubai). The stopovers are canceled to shorten the flight path and of course mainly because they take a lot of time: at least half an hour, usually twice as much.

But what does that mean for the extra fuel consumption you want to know. The maximum take-off weight of the Airbus A350-1000 to be deployed is 319 tonnes, Airbus notes. A maximum of 127 tonnes of petroleum can be taken and will probably also be taken on the trip to London. This means that the weight of the Airbus in Sydney consists of no less than 40 per cent fuel and explains why the payload (passengers and luggage) is only just 38.5 tonnes.

A heavily loaded aircraft uses more fuel per hour than an empty aircraft, the internet is clearly around this. But what is the connection really? That rule of thumb is that consumption is proportional to the aircraft’s total weight, says Delft’s aviation expert Joris Melkert. At the end of Qantas’ non-stop flight, hourly consumption can be up to 30 percent lower than at the start.

Practical calculations

The key question is how much more petroleum Qantas spends on its non-stop flight than on one- or two-stop travel. It’s easy to figure out if you can assume that Airbus always flies at the same speed. Van Melkert can do that. The aircraft’s gradual weight loss is now described by an ‘exponential function’ of a shape that also describes, for example, radioactive decay. Assuming that the aircraft will always arrive at the final destination or stopover with 15 tons of reserve fuel, the calculation shows that it costs 11 percent more fuel to fly than to fly with one stop and even 14 percent more than to fly with two stops. The consumption of the stopovers (approx. 2 tonnes) has been neglected.

Aviation expert and airline pilot Benno Baksteen offers more accurate practical calculations on a Boeing 777-200. These come out higher and suggest 19 percent extra consumption for a non-stop flight compared to a two-stop flight. For the environment and climate, 14 percent was bad enough.

Why, Melkert and Baksteen have been asked, why are the passenger planes not refueled in the air when it is so terribly busy. You can not, was the polite answer, and no one wants that. It is difficult and risky. Only US President Air Force One can do that. But it is also a military aircraft.

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