Lilium vertical take off "jet"

[mickjoebill]

Lilium Aviation
Another people carrying drone.
This simpler than others as it isn't trying to be a car.

Verticle takeoff and land using 36 electric fans.
2018 rollout.
The Lilium Jet, cruise 500km (310mi) max 400kph (248mph), and reach an altitude of 3km (9,900ft). Recharges overnight from a standard household outlet. Max range at 180mph. Autonomous landing.
Sports liscence.
360kw battery, over 400hp.
200kg payload.


I wonder what the endurance is in the hover...
The wing appendage that look like a flap is the array of motors that swivels down to hover.


Price of a Tesla maybe?

Mickjoebill

[Ascend Charlie]

The cg is WAY in front of the wing, with no canard to supply lift at the front, so that cylinder at the front will be permanently pointing down to provide upward thrust to counter the cg moment. Instant death if the battery goes flat or the motor quits.

Another dream of some dude playing with a 3-d drawing program and no understanding of physics. Where is the fan motor with its huge intake? Where do the wheels go? Will they add a "Verticle" fin for some stability? And just a little bit of sunburn from that big canopy.

[Freewheel]

Originally Posted by Ascend Charlie

The cg is WAY in front of the wing, with no canard to supply lift at the front, so that cylinder at the front will be permanently pointing down to provide upward thrust to counter the cg moment. Instant death if the battery goes flat or the motor quits.

Yeah, but you'll get a great view!

[DeltaV]

That looks daft.

I prefer this one,

and the CGI is better too.

[mickjoebill]

The 36 motors are distributed to create some redundancy.

Not sure about CG as the battery could be rearward and won't alter during flight


For reference
A boffin has torn down a Tesla battery. It is a good reference for the weight and specs of a state of the art battery
https://teslamotorsclub.com/tmc/thre...ry-pack.34934/
Tesla battery (LiCoO2):
Total 85kwh battery cell weight is 900lbs plus uber strong housing of 300lbs.
The pack contains modules. Each module weights 56 lbs and delivers 5.31kWh with a mass of 1001 in^2 -

Or 10.55 lbs per kWh
188.4 in^2 per kWh

Edit: The above are specs of a tesla car battery for reference. No specs released yet for the Lilium battery.

M

[Ascend Charlie]

Total 85kwh battery cell weight is 900lbs plus uber strong housing of 300lbs.

That makes 1200 lb or about 500kg, the total takeoff wt is 600kg, which minus the 200kg payload leaves an airframe of 400kg, 100kg short of the battery weight by itself - doesn't add up.

Go to the website, look for the photo looking up at the machine and see that everything is forward of the wing - it will not fly.

See also the pop-out cylinders for hovering - when they pop back in, the occupants' feet are crushed.

Looks very pretty, but somebody is playing with himself.

[mickjoebill]

That makes 1200 lb or about 500kg, the total takeoff wt is 600kg, which minus the 200kg payload leaves an airframe of 400kg, 100kg short of the battery weight by itself - doesn't add up.

It doesn't add up because the figures you quote include the weight of the massive battery frame needed to form the superstructure of the Teslar Model S car.
Base your power v weight calculations on the individual battery modules, these weight 5 kilos and deliver 1kWh.

No specs available on the batteries planned for the Lilium, so using the tesla battery modules as a guide.

In respect to what look like flaps, perhaps they are not required to reduce stall speed.

Wouldn't lifting the nose, let's say, 45 degrees and simultaneously gradually tilting the canard and wing fans downwards, produce a smooth transition from the wing providing lift to the fans taking over?

The Lilium is mentored by ESA, so hard to imagine that they are crackpots.

Mickjoebill

[Ian Corrigible]

The wing layout is reminiscent of the RQ-3A DarkStar, though the forward CG is far more extreme.

The propulsion approach is similar to the recently announced Aurora LightningStrike concept, which may have prompted the ESA 'business incubation' funding.

Given that the Lilium project was only "founded in February 2015 by four engineers and doctoral students," I'd say we have a better chance of seeing the sky blackened with Mollers, Hoverbikes or Terrafugias by 2018 than we do of seeing the Lilium reach the marketplace.

I/C

[mickjoebill]

I don't disagree with comments about the aerodynamic puzzle.
Hard to see how it can be controlled with the forward canards retracted.
The things that looks like wings may not need to produce much lift if motors are tilted down?

They claim 325kw/435 horsepower and endurance at cruise of approx 1hr 25min. Empty weight of 400kg.
Is this achievable if applying the specs of Tesla batteries of 5kilos per 1kWh? The Tesla modules themselves in an 85 kWh Model S are about 900 lbs. The other ~300 lbs is everything else for the pack.


Mickjoebill

[riff_raff]

The vertical lift efficiency of all those small diameter/high speed rotors will be miserable. And it's VTOL operation that drives the size of the electric motors/power electronics. An electric propulsion system sized for VTOL operation that accounts for less than 5% of total flight time usually means the motors/PEs will be over-sized for the other 95% of flight time in conventional (wing-borne) operation. This weight penalty can be significant.

Compare this to a battery-electric 2 seat rotorcraft that was actually built and flown. It was a modified S-300C helicopter which already had a well developed rotor system and lightweight airframe. The electric motor was rated at 141 kW which was the same power produced by the original Lycoming piston engine. The lithium ion battery pack weighed 1100 pounds which was limited by the S-300C max GW capability . This allowed around 15 minutes of flight with a single pilot on board.

I'm sure the engineers that designed the Firefly were competent, and the motor/controls/battery were all based on current technology. So it would be fair to use the Firefly's demonstrated performance as a baseline to evaluate concepts like Lilium.

[Rotorbee]

Apart from the things already pointed out - it doesn't even look as it should fly in an environment commonly know as air - , they should have studied the regs a bit more.
They want it to be a light sport aircaft.
A few points:
Max speed 180mp/h - Oh no. Max speed of an LSA can't be more than 138 mph.
No rotorcraft in the LSA category. Since it has lots of rotors, it disqualifies even multiple times.
One engine/motor only in a LSA.

... and a 600kg it would be just 1.2 kg too heavy for an LSA. But that's nitpicking.

Looks like somebody didn't even do the most basic research or they are just in the business to get crowd funding and then disappear to somewhere sunny ... to get in the mood for the project, I am sure.

[Ascend Charlie]

No pix of it on the ground or with wheels showing - where in the nose could you put a retractable nosewheel that doesn't get in the way of the retractable cylinders? Where would the main gear go and still leave room for a battery?

And just imaging the NOISE from 36 screeching little fans doing 15,000rpm to push some air downwards. Pure pud-pulling.

[Wageslave]

Come on, cut them a bit of slack, it's no more than silly verbiage applied to a series of pretty pictures drawn by someone with no knowledge whatsoever of aerodynamics.

It clearly isn't a serious proposal or anywhere close to one.

If anything it's a good troll judging by all the serious technical replies.

[Nige321]

drawn by someone with no knowledge whatsoever of aerodynamics

Really...??
Well either the armchair designers here are wrong, or this lot are...

We are a team of visionary aerospace engineers and product designers from the Technical University of Munich, Germany.
Our academic and professional backgrounds span from aeronautics and aerodynamics to robotics and ultra-lightweight structures. Initially funded by the European Union and supported by the European Space Agency and its Business Incubation Centre Bavaria we are developing the most advanced personal aircraft the world has ever seen.

[oggers]

This is the Lilium Jet, the world's first electric vertical take-off and landing jet

...just one problem with that: HELLO, it's only a pretend photo!

[mickjoebill]

And just imaging the NOISE from 36 screeching little fans doing 15,000rpm to push some air downwards. Pure pud-pulling.]

But its German visionaries say it will be much quieter than a helicopter!??

Some reasonable criticism of most of its specs on Pprune, are we losing something in the translation or are they onto something new?

Mickjoebill

[riff_raff]

"We are a team of visionary aerospace engineers and product designers from the Technical University of Munich, Germany. Our academic and professional backgrounds span from aeronautics and aerodynamics to robotics and ultra-lightweight structures. Initially funded by the European Union and supported by the European Space Agency and its Business Incubation Centre Bavaria we are developing the most advanced personal aircraft the world has ever seen."

Based on what this team is proposing, I would question their claims of expertise as "visionary aerospace engineers" or the ability to develop "the most advanced personal aircraft the world has ever seen". Unfortunately, this group of young inexperienced engineers will learn the cold, hard lesson of the difference between conceptual and real world designs. Those 36 tiny electric rotors will produce far less lift than they predict, the complete system will be far heavier than they predict, and it will be much more difficult to control this system than they predict.

[Ascend Charlie]

Then these "Experts" should know that it is far more efficient to accelerate a large amount of air to a low speed, then a small amount of air to a high speed, as well as the noise. Compare the noise and downwash disturbance from a 5-ton helicopter (S-76) in the hover to a Harrier jet.

And their claim to hold degrees from a particular university is far outweighed by my degrees and doctorates from Snotgobbler University, Noo Joisey, they cost me $50 each.

[Wageslave]

Initially funded by the European Union and supported by the European Space Agency and its Business Incubation Centre Bavaria

ie a glitzy prestige project funded by a irresponsible and financially corrupt body notorious for handing vast sums of cash as "subsidies" to anyone with a slick line of talk and maybe a bit of inside influence.
The "visionary" (quaaludes???) designers (aka ambitious permanent students) will live high on the hog for a few years just drawing silly pictures and issuing press statements before it all goes tits-up and they start again with another half decade of taxpayer-funded smoke, mirrors and champagne.
Not a bad lifestyle, all in all, even if it is ultimately one sponged off the taxpayer (ie us) with nowt to show for it.

[konradb]

this looks like

LightningStrike X-Plane ? Aurora

it is going to use the AE1107 turboshaft as used in the v-22 to drive 3 x 1 megawatt generators
will weigh 12000lb, 3000lb of fuel and 1500lb of payload