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Posted (edited)

This could be the early versions of the next generation of racing planes, which if it follows ice planes, the technology advancement will move to private planes. Have read a bit about the development of electric planes and it seems they are not that far away for short haul commercial flights, but for long haul, it's a long way off. These racing planes, or choppers, will probably result in 2 seater private planes and can;t understand why no one has yet incorporated solar cells in wings and fuselage, as that would dramatically increase range and once above the clouds, unlimited energy.

 

Long haul flights will probably go the hydrogen direction, hydrogen powered cars seem to go a long way on a small amount of hydrogen, one has just completed over 1300klms on a small 6-7kg of hydrogen.

 

"Airspeeder, a flying racing car that can go from 0-62 miles per hour in just 2.8 seconds akin to Formula One racing cars, has had a successful dual test run for the first time.

 

The test flight of two unmanned Airspeeder vehicles, in skies over an undisclosed location near Adelaide, South Australia at the end of September, marks the first time two units have taken to the air together."

https://www.dailymail.co.uk/sciencetech/article-10084123/Worlds-electric-flying-race-cars-skies-Adelaide.html

Edited by Dax
Posted

The craft is powered by a lithium polymer battery which allows it to fly for about 15 minutes. 

 

Since these were created for something like pylon racing, the short battery life isn't worth discussing in relation to the use of this type of aircraft for general flying. They say that when used for racing, the races would involved "pit stops" every 15 minutes and that a battery change would take 20 seconds. 

 

Sounds like a fun new vehicle racing sport for spectators and crews alike, but watch CASA stuff it up.

  • Agree 1
Posted

People love to compare EP flight with the Wrong Bro’s etc! Got nothing to do with that! EP is about propulsion not the birth of flight! But I guess you lot keep me entertained😂😂

Posted

The point I was trying to make was that when things first are invented, they might be flimsy or not very good, but once invented, they are soon improved upon. Remember Dick Tracey's wrist phone? A figment of the imagination? On January 13, 1946, the two-Way Wrist Radio became one of the strip's most immediately recognizable icons, worn as a wristwatch by Tracy and members of the police force. This radio wristwatch inspired Martin Cooper's invention of the mobile phone and may have inspired later smartwatches.

 

These electric flying racers are "rudimentary" at the moment, but if the sport flourishes (I was almost going to say 'takes off'.) who knows what will come from the development of its technology. Technological advancement is much more rapid in the 21st Century than at any other time in history. 

  • Haha 1
Posted (edited)

Solar cells in wings and fuselage are not practical in application at this point in time, simply because current solar cells weigh too much.

I had a new 6.6Kw solar system installed on the house today. The 10 yr old solar panels we pulled down are 800 x 1500mm, produce 190 watts, and surprisingly - weigh 17 kgs each.

The new ones I put up are 1M x 2M, are 370 watts output - and they still weigh 20kgs each. The frames are aluminium, so no weight there, the weight is in the actual photovoltaic cells.

 

Edited by onetrack
  • Like 1
Posted

As you say, One T. Consider the fact that solar energy, at best, offers about one kilowatt of total energy per square metre.

A conventional two seat light aircraft has about ten square metres of wing.

It's obvious that even if solar cells could convert SUN to electrons with 100% efficiency, the approximately ten square metres of wing can't possibly produce the required 80 kilowatts required for flight.

And as a range extender for a battery powered aircraft, they can only offer maybe 10% extension.

Solar on the back of aircraft can never provide the required energy.

Posted

Surely the success of the Wright brothers hinged as much on their ability to build a lightweight engine as it did on their flying knowledge.

They did build their own engine.

Posted
21 hours ago, Fliteright said:

We shall ALL be dead before EP planes go beyond the curious phase! 😂

Ignorance is bliss for some isn't it, electric commercial planes are already flying and development is well advanced. Of course it's in the beginning stages and we may not see big planes for a decade or so, but short haul are already viable and in production.

 

14 hours ago, onetrack said:

Solar cells in wings and fuselage are not practical in application at this point in time, simply because current solar cells weigh too much.

They already are building cars with solar cells in the roof and a solar cell only weighs 8-9grams. There would be no weight problem with solar cells embedded in wings and fuselage and as E planes are mostly carbon fibre, integrating solar cells into the wings and body would be easy. If they added super capacitors into the body, they could charge them whilst on the ground and use their stored power for takeoffs, which is where the majority of energy is used in flight.

 

One plane I've read about had props front and rear of the wing, both are used for takeoff and the front blades fold away during flight. There is already a caravan converted to electric flying round and many others, here's some links for any interested in what we can look forward to in the future.

 

https://www.airbus.com/innovation/zero-emission/electric-flight.html

https://www.bbc.com/future/article/20200617-the-largest-electric-plane-ever-to-fly

https://www.nasa.gov/feature/glenn/2019/nasa-us-industry-aim-to-electrify-commercial-aviation

https://www.greenbiz.com/article/6-electric-aviation-companies-watch

 

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Posted

A bloke  (employee) called Taylor built Wright's first engine. It was on its side and made an inadequate 16 HP and overheated. Glen Curtis offered to do the job but Wrights didn't want that. A significant aspect of their achievement was learning to fly it which was quite a challenge and it had roll control by wing  warping when others just used the further effect of rudder. with a lot of skidding. Nev

  • Informative 1
Posted
1 hour ago, Yenn said:

Surely the success of the Wright brothers hinged as much on their ability to build a lightweight engine as it did on their flying knowledge.

They did build their own engine.

Lawrence Hargrave was the first to fly in the late 1880's at Stanwell park, the wright brother used his engine design to build their own and that 3 cylinder rotary was the standard for many years

Posted
3 hours ago, facthunter said:

Wright's first engine. It was on its side and made an inadequate 16 HP and overheated.

Don't forget that in 1902/3 IC engines were not built anywhere as well as even engines twenty years later. The science of carburetion was in its infancy, as was ignition timing. Also the fuel was of a low quality compared even to the fuel of the 1920's. It is a wonder that the engine ran at all.

 

Everyone thinks that the Wright Bros pulled a rabbit out of a hat with their Flyer, but the general construction was an application of a lot of previously published data - Hargrave's stuff included. Before them, the means of introducing pitch and yaw were settled. The Wright Bros' contribution was to develop (invent) a means of controlling roll. During their experiments in 1902 the Wrights succeeded in controlling their glider in all three axes of flight: pitch, roll and yaw. Their breakthrough discovery was the simultaneous use of roll control (with wing-warping) and yaw control (with a rear rudder). The patent's importance lies in its claim of a new and useful method of controlling a flying machine, powered or not. The technique of wing-warping is described, but the patent explicitly states that other methods instead of wing-warping, including ailerons, could be used for adjusting the outer portions of a machine's wings to different angles on the right and left sides to achieve lateral roll control.

 

And you've been sucked into the belief that Horsepower is the god to be adored. Look at the performance figures they wanted from their propellers

Wilbur designed and carved his first full-size set of propellers -- 102 inches (2.6 meters) long, tapering from 6 inches at the tip to two inches at the hub (15.2 cm to 5 cm). Wilbur had determined they would need 90 pounds of thrust to sustain the Flyer in flight at 24 mph (38.6 kph). When tested at 245 rpm, the props fell short of the mark. Wilbur determined that the reason was that the propeller pitch (the angle at which the blade met the air) was too steep. 

 

In March, he began designing an improved prop and by June 1903 he had carved two of them -- one to turn clockwise on the right side of the Flyer and the other to turn anti-clockwise on the left. (Brilliant insight).  When the brothers finally did get a chance to test these propellers on the fully assembled Flyer at Kitty Hawk, they found they produced a combined thrust of between 120 and 130 pounds at 330 rpm. They were also remarkably efficient, converting 66 percent of the mechanical energy from the motor into thrust.

 

The Wright Bros didn't need a high HP engine, they needed torque to turn those props. These are the specs for their 1903 engine

Specifications:

  • Cylinders: 4
  • Stroke: 4 in (10.2 cm)
  • Bore: 4 in (10.2 cm)
  • Displacement: 201 in3 (3.3 l3)
  • Horsepower:12
  • Ignition: Make-and-brake powered by low-tension (10-volt) magneto.
  • Weight: 180 lbs (81.6 kg)
  • Unique features: Aluminum block, no carburetor.

An engine that develops 12 HP at 330 RPM produces 190 poundsforce.foot torque

 

There is a formula for converting torque to thrust, the thrust F generated by the propeller disk is equal to the pressure change, delta p, times the propeller disk area A:

F = delta p * A

That formula uses a bit of Bernoulli, so I'm not going any further.

  • Like 3
Posted

An improved engine was quickly made, bigger and upright  with better combustion chamber design as the first plane had no wheels and also was catapulted on rails to get airborne. A prop failed at the hub killing  some military guy. as it was too thin in that area.  The prop rpm was much below the engines.

  190 ft/lbs torque from that engine ? it would never take it or make it.  Nev

  • Informative 1
Posted

There's plenty of questionable "facts" about these days to distract and confuse research. The BEST/MOST reliable basis  is from what was documented at the time. Apply simple Physics to what is known as a fact. Look up BMEP. Brake Mean Effective Pressure which was an index of engine output capability and efficiency in common use with piston engines used in aircraft.. Nev

  • Like 1
Posted

One of the first to fly was  plane designed and built by Cayley, I think that was his name. It must have been easy to contol because his coachman was the  pilot for the first flight and quit the job immediately after. Just surviving was a miracle as far as I can see.

  • Agree 1
Posted

There's "flying" and there's "controlled flight". Cayley's 1803 aircraft was a glider. (He knew that sustained flight could not be achieved until very lightweight engines were developed.) The glider design established the general layout of wings, rudder/tailplane and Centre of Gravity. However, there does not seem to have been any means of coordinating turns with wing lift devices. It was the Wright Bros who attacked that problem and defeated it. They showed how to control an aircraft in three dimensions.

They also had a century's worth of engineering experience in engine creation to be able to design and have built engines with a suitable power to weight ratio for the task they set it.

 

There were others in obscure places at the same time as the Wrights who fitted engines to the basic Cayley design, but if you read descriptions of their flights, they were mainly straight line. and often ended with a wing drop onto the ground, if they didn't fail to clear hedges in their path.

 

16 hours ago, facthunter said:

190 ft/lbs torque from that engine ? it would never take it or make it. Apply simple Physics to what is known as a fact.

Too true. According to the conversion equation, there is a linear relationship between HP and Torque. In theory, you could calculate the HP the Wright's engine could develop at, say 2750 RPM, from the values at 330 RPM. But I reckon that before the engine got to 2750 RPM, there would be bits of engine hurtling through the workshop.

Posted

The engine was very low compression and thermally as far as efficiency goes very bad, It's volumetric efficiency was also bad. It was a good effort at the time  and to build it in house, especially.  I'm not one to decry the Wright's place in aviation history. Even when they belatedly and after much criticism, turned up at Paris the demo flight was widely acclaimed by the French and Flyers were built under licence by the French. The aircrafts ability to be turned and manouvered was acknowledged.. Nev

Posted

It's really not so strange that the Wright brothers developed roll control.  They were bicycle manufacturers, remember.  If you ever try to turn a bike at more than walking pace without leaning into the corner, you'll realise why they would automatically think of rolling an aircraft to turn it.

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  • Agree 1
Posted

You will find that railway tracks built for passenger trains that travel a bit quick, have camber in their curves so that they can maintain a designed speed through the curve. I'ts not so important for goods trains which usually don't travel as fast as passenger trains.

  • Agree 1
Posted

When I studied engineering there was a formula for super elevation of the outside rail. I thought it was done for all railway tracks on curves. As you say, there has to be an assumed speed but even goods trains would need it.

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