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@N201MKTurbo Posted:

So, what would it take to make an electric Mooney.

200 HP is 150 KW, so 75% power is ~ 115KW. 

Lets look at a 5 hour flight with 1/2 hour at 100% power and 4 1/2 hours at 75% power.

75KWH for climb + 517 KWH for cruise, that is 592 KWH.

Using the magic 500WH/KG battery, it would 1184 KG of batteries or 2600 Lbs of batteries to replace 384 Lbs of AVGAS.

Payload wise, it makes a Rocket look good!

Using the California electricity rate of $0.15/KWH that costs $88 for a tank of electricity, not bad...

One thing nobody mentioned, no turbo required! You can climb up till you need a pressure suit and hit the coffin corner. How do propellers work in the thin air above the RSVM airspace?

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You know -  Blue on Top one more great thing about electric that is uniquely electric vs any other power plant - 

The actual motor is usually much smaller than anything burning liquid fuels.  So the frontal area of a motor on the nose could be quite narrow.  And lots of batteries in the wings.

On the other hand - who has seen this thing - 2 big props at the wing tips and what - 20 little motors on the wings.  You have a whole new world of possibilities when working with electric motors.    Imagine a Mooney looking airplane with 14 props like that nasa experimental.

There are fantastic and interesting stall characteristics and efficiency characteristics when actually driving the air directly over the wing from lots of tiny motors on the wings. 

Edited by aviatoreb
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@N201MKTurbo Replied to @Danb with:

The problem is hydrogen isn’t a fuel, it is an energy storage medium. There are no hydrogen mines or wells. You have to make it, probably from and with fossils fuels. It will never de cheap.

Even as a storage medium it has problems. It isn’t very dense, even liquid has less energy per gallon then AVGAS. A liquid dewar is hard to make light and they all need maintenance eventually. It would be hard to keep the vacuum space leak free in an airplane bouncing around in turbulence. After the vacuum goes away the liquid will be gone in a few days and even if it’s perfect, you will probably loose 1/2 your fuel every month. If you wanted to use compressed gas, you would need something like 20 or more bottles the size of the big oxygen bottles. Where are you going to put those? 

If you do somehow find a place for all the hydrogen, forget an internal combustion engine! Get a fuel cell and go electric. The fuel cell will make the rest of the airplane look cheap, but we are dreaming.... right? 

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I think we are more apt to see something like the "Black Fly" in the near future for short trips and fun flying, I'd love to fly one of these. I live 9 miles from Wally World. Would love to jump in and fly there land in the parking lot get what I need and fly back home. 

 

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25 minutes ago, cliffy said:

I think we are more apt to see something like the "Black Fly" in the near future for short trips and fun flying, I'd love to fly one of these. I live 9 miles from Wally World. Would love to jump in and fly there land in the parking lot get what I need and fly back home. 

 

Could they put a Mooney tail on that please? :rolleyes:

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Let’s think about a twin engine hybrid. The engines would be in nacelles like current twins. They would have no propellers but would be motor generators. The combined power would equal the required cruise performance plus charging the batteries for takeoff, climb and emergency power. The slim line motors would be in the nose. There would be two motors for redundancy in a coaxial arrangement, each motor turning a counter rotating (or not) propellor. 

For takeoff and climb, the motors would run on engine plus battery power. While in cruise, the excess power from the engines would charge the batteries for the next takeoff. In the case of an engine failure, a light would come on telling it is time to find an airport to land at. If a motor or propellor failed, the failed prop would feather and you could operate on takeoff power on one motor with no blue line problems.

The most  dangerous time would be at the top of climb, with depleted batteries, in the case of engine failure, you would only have 1/2 cruise power available, which would probably hold altitude at a slow airspeed. 

In all situations, more efficient then current twins and certainly safer!

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All these person hauling quadcopters, while certainly electric aircraft, probably scale similar to photo drones. They don’t have spectacular range or endurance.  A half an hour or so. Beyond that any increase in size is just to haul the extra batteries and the endurance doesn’t change much.

Does anybody have design formulas for quad copters with respect to time, speed and battery requirements?

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1 hour ago, cliffy said:

I think we are more apt to see something like the "Black Fly" in the near future for short trips and fun flying, I'd love to fly one of these. I live 9 miles from Wally World. Would love to jump in and fly there land in the parking lot get what I need and fly back home. 

 

I'll go with you to Wally World in that.

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2 hours ago, Blue on Top said:

@salty Replied to @mike_elliott with:

That’s what they’ve been saying for more than 50 years. Good luck with that. 

Mike Elliott replied to Salty with:

Fortunately, the FAA doesnt have to "approve" the technology developed by HiBar, Maxwell technologies and Tesla. Their dry lithium batteries save a ton of weight. Stay tuned, Sept 15th will make the TSLAQ's hurt that much more.

 

 

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Hmmmm...

The coolest oddity of electric motors...

They can derive max torque from zero rpm all the way on up....

Where a typical V8 has to be well above 2krpm...


So.... 0 to T/O speed can come up quickly, aka shorter T/O roll....

 

The second coolest oddity of electric motors...

They can put energy back into the batteries....  so each time we would normally use the speed brakes.... instead of turning the excess energy into wasted heat... we could  store the energy back in the battery instead....

I typically select altitudes for really long glide distance safety....

 

Way to go Ron!

Have you seen any fo the formula e racing? (Automotive world)

Best regards,

-a-

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Energy density by weight. Land as heavy as you take off. For aerodynamic cars, drag doesn’t overtake rolling resistance until you’re north of around 50mph. Most cars need no more than 20-50hp to maintain highway speed. Can a Mooney even maintain altitude at those power settings? Battery powered airplanes are a stupid thing to pursue these days. Efforts for hybrid gas+electric would be far better use of engineering resources as the electric propulsion has room for development and can leverage economies of scale from new power source designs in the future. 

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I think I'm all caught up … again :) 

Everyone is right, but you're talking fruit salad (LOL).  Apples, oranges, bananas, grapefruits, prunes, melons, etc.  I've been doing electric airplanes for a couple decades now.  Is it possible at this time to replace a "J" with an electric airplane.  NO!  But .. we need to do things to get there in the future … when some form of electrons can be stored in a lighter version.

First, let's get physics out of the way.  Automobiles use 20-30 HP going down the road at highway speeds.  @mike_elliott can tell you exactly.  His Tesla tells him.  An airplane (the "J") uses 200 HP on takeoff and 150 HP the rest of the time.  Not comparable.   Electric motor low-end torque is irrelevant; the propeller is the torque absorber … and it needs RPM … sorry @carusoam.  Automobiles care about weight, but only for acceleration.  Airplanes pay a drag penalty for weight depending on the L/D ratio.

At this time (and this is only my personal thought), hybrid is the only way to go at this moment in time, and here is why.  Batteries (or any other form of energy storage) is not there yet.  But, if we can get 30 minutes of battery power for an airplane, an on-board genset can supply the power for flight.  Yes, it would be heavier.  The engine can be a Chevy, Ford, etc., because if it craps out, the pilot still has 30 minutes to get the airplane on the ground.  This could be a certificated installation … I know, I'm on the ASTM committee writing these "regulations."  I DEFINITELY DON'T KNOW IT ALL, though.

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So... i fell down on the max torque available at zero rpm argument... Darn-it... :)

 

never deterred... I’ll start again...
 

The really coolest thing about electric planes....

They can fill themselves with energy, while parked in the hangar...

free electricity using solar collectors...


 

Mr. Elliot, do you have solar energy feeding your Tesla?

That is the kind of numbers I need to make the trigger pulling argument...

I have friends with Teslas...

I have friends with solar collectors...

I need an engineer level friend that can put these figures together...

At this time... various discounts seem to be necessary to make things break even...


Back in the day... prior to retirement, my gasoline costs were over $500 each month... (rough estimate)

My airport friend with the Tesla, took me for a ride down the runway...  :):):)

That’s a heavy car... it may use a few extra things like tires...

PP thoughts only...

Best regards,

-a-

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3 hours ago, MikeOH said:

Wonder what the glide ratio of that thing is?

Count me out!

Like a helicopter only without the auto-rotate feature- like a bent manhole cover BUT it has 8 motors and can fly on 6 IIRC

Rotating thrust vector aircraft will be the first "usable" all electric vehicles for short range travel across cities- IF the noise can be negated!!! 

BTW, the range of 26 miles (with reserves) is currently limited by Federal laws regarding Ultralight Vehicle Performance Limitations  not engineering. 

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