Siemens 260kw electric motor weighs 50kg...

[Wedgetail]

http://interestingengineering.com/si...-for-aircraft/


2mm flexible solar panels on UML of wings, battery packs, and the electric motor.
Perhaps also a small IC motor driving an AC alternator/rectifier?

Anyone want to start planning for vans fitment?
Brings me to the next question:

What will the 2025 experimental vans rv look like !

[GalinHdz]

Originally Posted by Wedgetail

Brings me to the next question: What will the 2025 experimental vans rv look like !

Maybe something like this:



The RV-X wing, Van's first multi engine bi-plane. But it might require a Garmin R2D-296 (or similar) navigator for 2025 ADS-B compliance.

[meloosifah]

I am still waiting for the miracle battery pack. Great advances in motors still leave us tied to fuel because it's the batteries that weigh so much. I have an electric motor for a model that paired up would power a small plane - just can't get any endurance due to energy storage weight.

[Mike S]

Julian-------welcome to VAF

You are at least the third person to "Discover" this motor, and post a thread about it.

Hopefully someday the science and engineering folks in the battery world will be able to catch up with those in the motor world.

It is a nice dream---------but at the current state of reality, only a dream for us.

[BillL]

Welcome Julian,

Function Replacement theory requires some new thinking. What if . .

the airframe (w/o powerplant and fuel) weighed (gross) at 1160 pounds, and it had a best glide sink rate of 2 ft/sec, and it was already carrying 450 lbs of ballast? Think - - sailplane. That is 3.1 kw BTW to keep the velocity and zero sink rate. If my calculations were correct.

Now, think replace that 450 lbs of ballast with 400 lb of batteries. At 150 watt-hrs/kg. That yields 7 hour range with an 80% motor/inverter energy conversion! The catch is takeoff and climb. But, at least it is a start.

Oops, forgot about prop efficiency, drop the range by another 20%.

Now, back to work on something mundane, like fiberglass work on my 7.

[bret]

Originally Posted by BillL

Welcome Julian,

Function Replacement theory requires some new thinking. What if . .

the airframe (w/o powerplant and fuel) weighed (gross) at 1160 pounds, and it had a best glide sink rate of 2 ft/sec, and it was already carrying 450 lbs of ballast? Think - - sailplane. That is 3.1 kw BTW to keep the velocity and zero sink rate. If my calculations were correct.

Now, think replace that 450 lbs of ballast with 400 lb of batteries. At 150 watt-hrs/kg. That yields 7 hour range with an 80% motor/inverter energy conversion! The catch is takeoff and climb. But, at least it is a start.

Oops, forgot about prop efficiency, drop the range by another 20%.

Now, back to work on something mundane, like fiberglass work on my 7.

10,000 farad CAP for take off...http://www.marketwatch.com/story/sun...tor-2015-05-06

[rv7charlie]

My favorite quote from that article:

quote:
The power-to-weight ratio of this engine, which breaks all previous records, opens up the possibility of larger aircraft with takeoff weight of up to two tons and capacity for up to 100 passengers to use an electric propulsion system.
unquote

(Do the math.)

Having said that, I think that the naysayers are a bit like ferriers in the early 20th century who saw no need to retrain for other jobs.

[sblack]

If you look at any very large scale electric powered model, and there are lots out there, the motors are tiny relative to the airframe. It's sort of like a turbine engine in that they are tiny and put out massive hp for their size. But the battery for the electric is the issue, just like the extra fuel burn is the issue for the turbine. So a new super light motor does not change the equation.

Back in the 80s we were flying 6 cell nicad rc models, made like old rubber powered designs so as to be light as possible. We were getting 3 min on a good day and the gas guys would laugh at us and shake their heads. Then lipos came out and over night everything changed. You could fly two 15 min flights one one charge with the same performance as the "Slimers". Ok we had the odd fire but hey...that's the orice if progress.

Electric airplanes are at the same stage as electric rc was in the 80s - for die hard tinkerers and very high tech super light, low drag airplanes. But if there is a new battery technology it will change very quickly.

[Mike S]

Originally Posted by rv7charlie

The power-to-weight ratio of this engine, which breaks all previous records, opens up the possibility of larger aircraft with takeoff weight of up to two tons and capacity for up to 100 passengers to use an electric propulsion system.


(Do the math.)

OK, 100 passengers at the FAA mythical 160 lbs is 16,000 pounds or 8 tons. In reality it will most likely be higher.

Add the two tons of airframe--------pretty mythical also for a hundred passengers (The Concorde carried about a hundred passengers, and weighed 80+ tons-------empty. Boeing 737-100 apx 100 passengers, 30+ tons empty. DC 7--just under a hundred passengers, 29 tons) -------and you get 10 tons.

Now you want to fly that on 350 HP???

Originally Posted by rv7charlie

Having said that, I think that the naysayers are a bit like ferriers in the early 20th century who saw no need to retrain for other jobs.

I think the horse shoers are safe for a little longer.

[Jordan1976]

Originally Posted by bret

10,000 farad CAP for take off...http://www.marketwatch.com/story/sun...tor-2015-05-06

I can design a 10,000F capacitor that can't power a watch for more than a second and a 1uF capacitor that has enough energy to take a 747 across the Pacific.

Without stating what voltage it operates at, the capacitance measurement is worthless in determining how much energy it stores. It's exactly the same as saying "I have a 400V battery!" without mentioning that it has only 1mA of capacity.

For instance, that capacitor at 1.2V (Standard for a Graphene capacitor) would only produce 200HP for .05 seconds (yes, 1/20th of a second).

For a 2 hour flight, you'd need 144,000 of them. At the current weight/volume of supercapacitors, that would be about 300,000 lbs and 4,800 cubic feet of volume.