What do you think about "e-soaring"?

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opcod

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Aug 28, 2010
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79
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Canada
Hi Martin, i re-read about the continuous power and what you said about : in level flight..
If you run the motor at a needed 30kw of power and you read a 30 amp with your 35kw batt pack : so what is the flight duration with like only 2 takeoff ? (no thermaling.. engine running all time)

Do you also base the calc on the prop low efficiency and always with the 30min flight reserve ( as per regulation) ?

thanks for precision
 

John.Roo

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Oct 8, 2013
Messages
692
Location
Letohrad / Czech Republic
Hi Martin, i re-read about the continuous power and what you said about : in level flight..
If you run the motor at a needed 30kw of power and you read a 30 amp with your 35kw batt pack : so what is the flight duration with like only 2 takeoff ? (no thermaling.. engine running all time)

Do you also base the calc on the prop low efficiency and always with the 30min flight reserve ( as per regulation) ?

thanks for precision
Hi!
Well.... I summary my experience.
Motor is designed for 80 kW be we limited max, power to 60 kW because Phoenix really doesn´t need more (maybe except aerotowing).
Battery has nominal Voltage 345 V. Max. voltage 398 V.
For TakeOff I need +-160 Amps, for 30 kW climb I need +-80 Amps and for horizontal flight I need +-30 Amps.
You can see it here:
I can use 60 kW for max. 3 minutes, but usually I reduce 60 kW earlier and I continue to climb at 25-30 kW.
During level flight I use 12 kW at speed 120-130 km/h.
I really take care of batteries so typically I don´t cross 2 hours flights and I land with min. 30% reserve.
In Denmark I did 10 takeoffs / 1x recharge with pilots interested to test electric Phoenix. In this case I typically climb to 300-400 m and than I fly rest or circuit with no power.

I will now repeat myself, but I beleive that (at least in EU) make more sense to install smaler battery (20-25 kWh) and install to airplane also 10-15 kW charger. Here is no net of chargers and make no sense to wait till chargers are available. So to make electric airplane independent is etter to decrease endurance to +-90 min with reserve but with large advantage to recharge everywhere. In EU are 220 V or 400 V sockets on nearly all airfields.

In US (maybe also in Canada) is situation different.
I don´t know what is max. power available on typical airport. If I remember well it is typically 1 phase 110-120 V and 15 Amps. Much better would be to use 3 phase (as we do - 400 V / 16 or 32 Amps).

I beleive that key is to use variable pitch prop to keep efficiency of motor at 90%. It will increase efficiency of whole system + it will help to cool down the motor. But this has to be done automatically :)

As battery capacity is limited is important to "play" with details. Every % is important.
If I see 12 kW going from battery it means that Phoenix needs less than 8 kW.
Efficiency numbers I normally use is:
Prop 80%
Motor 85%
Controller 95%
+ something for wiring etc.
So finally you get max. 65% eff. of propulsion.... what a waste of energy :)

Best regards!
Martin
 

opcod

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Joined
Aug 28, 2010
Messages
79
Location
Canada
Thanks that's the pretty good picture. Indeed, in america it's more like the only high power available are the few tesla power system. In fact it's for standards ev and the few present are outside of the taxi way. And even those, the highest power is 1phase / 240v at 40amp. The solar approach with cell over the entire wing are a nice option, but even on the sunseeker, it's at most a 1.8kw gain with great sunny day and it cost about 55k for the cell alone. But i'm big fan of motorglider and even good time on a sinus too. But running at 1;26 is not enought.
*with the 17m or 16m version.. did you expect to get a 1:33 ?
 

John.Roo

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Oct 8, 2013
Messages
692
Location
Letohrad / Czech Republic
Thanks that's the pretty good picture. Indeed, in america it's more like the only high power available are the few tesla power system. In fact it's for standards ev and the few present are outside of the taxi way. And even those, the highest power is 1phase / 240v at 40amp. The solar approach with cell over the entire wing are a nice option, but even on the sunseeker, it's at most a 1.8kw gain with great sunny day and it cost about 55k for the cell alone. But i'm big fan of motorglider and even good time on a sinus too. But running at 1;26 is not enought.
*with the 17m or 16m version.. did you expect to get a 1:33 ?
Yes, with 17 m wig extensions we expect to get to 1:33 or better.

The high power electricity really seems to be a problem in US.
But 240 V / 40 Amps = +-9,6 kW and that is not so bad.

I agree that solar panels on the wings are actually not really a way.
Energy you get is low in compare with complexity of this soltion. This may will improve in future, but so far is probably better to have solar panels of roof of hangar :)
 

John.Roo

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692
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Fixed wing, 5 seats....
Of course so far is still jut a nice render, but at least seems that they understand that electric airplane must be efficient :)
Elektron.jpg
 

EzyBuildWing

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Sep 23, 2009
Messages
200
Location
Sydney NSW Australia
Electron Aviation's website is impressive and convincing for this 5-seater.
.....crowd-funding on kick-starter perhaps?
Perhaps pilot-instructor PLUS 4 students would make it an excellent-choice for flying-schools?
 

John.Roo

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Oct 8, 2013
Messages
692
Location
Letohrad / Czech Republic
Electron Aviation's website is impressive and convincing for this 5-seater.
.....crowd-funding on kick-starter perhaps?
Perhaps pilot-instructor PLUS 4 students would make it an excellent-choice for flying-schools?
I am not sure if you need 4 students aboard for training. For some lessons could be probably usefull (navigation?), but generally weight = energy consumption. 3 studends sitting on rear seats = at least + 200 kg (realistically +250 kg).

The reason why I mentionned this project is configuration.
If I look to some 3D renders of electric airplanes I have to ask myself - how they want to achieve optimal CG position? Here you can see all 5 passengers in the front of "glider like" wing (high aspect ratio). Imagine CG position difference for 1 pilot of for 5 persons.
In Electron case I suppose that CG is solved by front stabilizer. So during stall you loose lift on front stabilizer. Than is CG moving a lot forward = nose down and building up speed.
I am not sure if this is real purpose, but makes sense to me :)
Canards are working the same way. Electron has also "standard" tail surfaces and this is something I personally like because it could help to achieve standard recovery from not standard situations.
On their web is info that they would like to make scale model. Well... I am not really fan of "scaled models". RC model can be done with much better weight/power ratio. I would prefer to see for example one seat prototype with similar configuration. That would be much more convincing ;)
1614399021250.png
 

henryk

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Mar 8, 2010
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5,889
Location
krakow,poland
airplane also should look nice
=air particles are not good in "nice view" criteria...

-for me,the old gliders and cars was more byuty then todays one !

BTW= PHOENIX pilot in taxii mode
"have a nice view :)"?

 

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John.Roo

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Oct 8, 2013
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Letohrad / Czech Republic
I agree - most of old gliders and old cars are beautifull.
But I also thing that "air particles" can feel if they are fluently going arround something nice :)

Design is a very subjective category... Celera seems to be interesting project. Is just not mine "cup of coffee".
I do a sport and fun flying = I need to have good view.
1614421744440.png
 

John.Roo

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Joined
Oct 8, 2013
Messages
692
Location
Letohrad / Czech Republic
Zero motorcycle power drive is high RPM system so it is necessary to use reduction.
Zero powerdrive kopie.jpg
Technical data are here:

Report about electric Xenos is here:

Gabriel contact info is here:
 
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