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$1 billion BMS Ooops...



 
 
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  #51  
Old March 4th 21, 10:55 PM posted to rec.aviation.soaring
Kenn Sebesta
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Posts: 48
Default $1 billion BMS Ooops...

A hybrid system with a gas engine wouldn't have the pucker factor associated with starting a
gas powered motorglider to avoid a landing: if the hybrid engine doesn't start, it just means
your potential retrieve distance is shorter, instead of an imminent landing.


I'll wade in here with some experience. Top Flight, a Boston startup specializing in hybrid propulsion systems, spend over half a decade developing their power unit. The hardest part for them was developing a unit which was reliable. Motors don't like vibration and they don't like heat. Combine the two together and the motor is not long for this world. It took a lot more R&D than anyone expected to make a lightweight package which could survive.

I would not expect anyone to be deploying this technology anytime soon. If and when it is commercialized, it will be useful for ferry flights of electric aircraft. For any use which requires permanent installation, you're probably better having it drive the propeller directly.

eGliders, I sense a tone here which is reminiscent of discussions about finally putting the 2-33 to rest. The US is no longer the forefront of light aviation, so we need to look east to see what the trends are. We know that leading glider manufacturers are racing to bring eGliders to market. A gentleman who works on glider competition rules noted this summer that glider records are falling left and right to eGliders. There is a growing group of amateurs who are pulling their engines out of their gas self-launchers and replacing them with electric (If you'd like to be a part of this group, DM me). The future was yesterday, but like any future it doesn't arrive at all places at once.
  #52  
Old March 4th 21, 11:00 PM posted to rec.aviation.soaring
Martin Gregorie[_6_]
external usenet poster
 
Posts: 699
Default $1 billion BMS Ooops...

On Thu, 04 Mar 2021 14:27:53 -0700, Dan Marotta wrote:

9,000 RPM makes quite a racket, no matter the muffler. Have a good
noise canceling headset...

Yeah, I know - the engine I took weight and power numbers was a 20cc RC
aircraft engine, while I was iriginally thinking of thre 20cc petrol
engines you used to see on small chainsaws and big drills.

But, add a bit of weight and bulk for water cooling and put it in a sound-
absorbing box with the motor/generator combo sat on rubber mounts and I
think you cound reduce the sound level quite a lot.

But, the main poing of my piece was to show just how light and relatively
fuel efficient such a small generator set would be compared with an
battery of equivalent capacity.

A litre of gas or diesel fuel weighs 800g and has an energy capacity of
9.7 kWh.

Totally OTT: As an ex-free flight model flyer, I think the finest engine
sound I've ever heard was a 1cc Cyclon-06 glow motor with an open exhaust
spinning a 7" x 4" prop at 30,500 rpm on 25% nitro fuel mix.



--
Martin | martin at
Gregorie | gregorie dot org

  #53  
Old March 4th 21, 11:15 PM posted to rec.aviation.soaring
Moshe Braner
external usenet poster
 
Posts: 114
Default $1 billion BMS Ooops...

On 3/4/2021 5:00 PM, Martin Gregorie wrote:
On Thu, 04 Mar 2021 14:27:53 -0700, Dan Marotta wrote:

9,000 RPM makes quite a racket, no matter the muffler. Have a good
noise canceling headset...

Yeah, I know - the engine I took weight and power numbers was a 20cc RC
aircraft engine, while I was iriginally thinking of thre 20cc petrol
engines you used to see on small chainsaws and big drills.

But, add a bit of weight and bulk for water cooling and put it in a sound-
absorbing box with the motor/generator combo sat on rubber mounts and I
think you cound reduce the sound level quite a lot.

But, the main poing of my piece was to show just how light and relatively
fuel efficient such a small generator set would be compared with an
battery of equivalent capacity.

A litre of gas or diesel fuel weighs 800g and has an energy capacity of
9.7 kWh.

Totally OTT: As an ex-free flight model flyer, I think the finest engine
sound I've ever heard was a 1cc Cyclon-06 glow motor with an open exhaust
spinning a 7" x 4" prop at 30,500 rpm on 25% nitro fuel mix.



I'd prefer a quiet engine, like the ones on small Honda generators.
Presumably 4-stroke, so a bit heavier, but very efficient (for a small ICE).

I'll leave it to the IGC folks to tear their hair out on how to deal
with the engine noise no longer being an indicator of (simultaneous)
propulsion.

Perhaps for a "sustainer" model you could run the engine only when you
decide you need propulsion, and have an engine large enough to supply as
much power to the batteries as the electric motor is using, or a bit more.
  #54  
Old March 5th 21, 12:30 AM posted to rec.aviation.soaring
Mark Mocho
external usenet poster
 
Posts: 108
Default $1 billion BMS Ooops...

"There seems to be an anomaly with your numbers: The 100 kWh battery delivers about 400 miles of
range. How is it possible to go that far on the equivalent of 2.1 gallons of Av Gas?"

Eric- the main reason that the numbers seem skewed is the relative efficiency difference between modern brushless electric motors (often over 90%) and typical Internal combustion engines, which barely reach 30% efficiency.

For a reasonable overview of the gas vs. electric debate, I highly recommend an article in the January 2021 issue of "AOPA PIlot" magazine entitled "hp versus kW" by Peter Rez, "an Arizona State University physics professor from Scottsdale who flies a Mooney."
  #55  
Old March 5th 21, 03:15 AM posted to rec.aviation.soaring
Matthew Scutter
external usenet poster
 
Posts: 42
Default $1 billion BMS Ooops...

On Friday, March 5, 2021 at 9:30:31 AM UTC+10, Mark Mocho wrote:
"There seems to be an anomaly with your numbers: The 100 kWh battery delivers about 400 miles of
range. How is it possible to go that far on the equivalent of 2.1 gallons of Av Gas?"
Eric- the main reason that the numbers seem skewed is the relative efficiency difference between modern brushless electric motors (often over 90%) and typical Internal combustion engines, which barely reach 30% efficiency.

For a reasonable overview of the gas vs. electric debate, I highly recommend an article in the January 2021 issue of "AOPA PIlot" magazine entitled "hp versus kW" by Peter Rez, "an Arizona State University physics professor from Scottsdale who flies a Mooney."


I think what he was trying to get at, is that comparing on the basis of energy density isn't very meaningful. We should be comparing distance-retrievable/kg and height-climbable/kg across different ICE and electric solutions.
  #56  
Old March 5th 21, 02:00 PM posted to rec.aviation.soaring
Hank Nixon
external usenet poster
 
Posts: 60
Default $1 billion BMS Ooops...

On Thursday, March 4, 2021 at 4:55:30 PM UTC-5, Kenn Sebesta wrote:
A hybrid system with a gas engine wouldn't have the pucker factor associated with starting a
gas powered motorglider to avoid a landing: if the hybrid engine doesn't start, it just means
your potential retrieve distance is shorter, instead of an imminent landing.

I'll wade in here with some experience. Top Flight, a Boston startup specializing in hybrid propulsion systems, spend over half a decade developing their power unit. The hardest part for them was developing a unit which was reliable. Motors don't like vibration and they don't like heat. Combine the two together and the motor is not long for this world. It took a lot more R&D than anyone expected to make a lightweight package which could survive..

I would not expect anyone to be deploying this technology anytime soon. If and when it is commercialized, it will be useful for ferry flights of electric aircraft. For any use which requires permanent installation, you're probably better having it drive the propeller directly.

eGliders, I sense a tone here which is reminiscent of discussions about finally putting the 2-33 to rest. The US is no longer the forefront of light aviation, so we need to look east to see what the trends are. We know that leading glider manufacturers are racing to bring eGliders to market. A gentleman who works on glider competition rules noted this summer that glider records are falling left and right to eGliders. There is a growing group of amateurs who are pulling their engines out of their gas self-launchers and replacing them with electric (If you'd like to be a part of this group, DM me). The future was yesterday, but like any future it doesn't arrive at all places at once.


What is contact info for the list mentioned?
Thx
UH
  #57  
Old March 5th 21, 04:50 PM posted to rec.aviation.soaring
Kenn Sebesta
external usenet poster
 
Posts: 48
Default $1 billion BMS Ooops...

On Friday, March 5, 2021 at 8:00:05 AM UTC-5, Hank Nixon wrote:
On Thursday, March 4, 2021 at 4:55:30 PM UTC-5, Kenn Sebesta wrote:
... There is a growing group of amateurs who are pulling their engines out of their gas self-launchers and replacing them with electric (If you'd like to be a part of this group, DM me)...

What is contact info for the list mentioned?
Thx
UH


While Google Groups no longer displays email addresses, they can be pulled from RSS readers. I sent you an invite.

(Sometime in the near future I'll set up a better way to join the group.)
  #58  
Old March 5th 21, 05:29 PM posted to rec.aviation.soaring
2G
external usenet poster
 
Posts: 1,439
Default $1 billion BMS Ooops...

On Thursday, March 4, 2021 at 8:22:34 AM UTC-8, Eric Greenwell wrote:
2G wrote on 3/3/2021 6:11 PM:
On Tuesday, March 2, 2021 at 8:27:55 PM UTC-8, Eric Greenwell wrote:
2G wrote on 3/2/2021 7:25 PM:
On Tuesday, March 2, 2021 at 6:28:27 PM UTC-8, Andrzej Kobus wrote:
On Tuesday, March 2, 2021 at 4:10:48 PM UTC-5, ProfJ wrote:
On Wednesday, 24 February 2021 at 14:42:01 UTC-7, wrote:
https://insideevs.com/news/490300/hy...ll-82000-bevs/
Discus amongst yourselves...
Some comments:

- High current draw for VTO launches (Lilium) - IIRC they are planning to use supercapacitors to provide the current boost so that the batteries don't have to. A supercapacitor/LiPo combination makes a lot of sense for that problem.

- Electric vs. gas: a very experienced motorglider ferry pilot, who I am sure does not want to be named, once told me when discussing Stemmes: "I've had every known Stemme issue except the in-flight fire, I'm not looking forward to that one..." I side with Eric here - we have normalized all the hassle that goes with gas self-launchers. When we get mature technology electric self-launchers, they'll dominate. Current complaints about electric sound exactly like the complaints about electric cars, before Tesla got it right.
So how big is the electric glider market vs. electric car market? Things get done with proper research and funding. I don't see that happen for the glider market. I suggest you review David's presentation. He discussed this point.

ICO glider engines have been developed over the last 70 years or so. And, then, many of them have come from the 2-cycle engine applications such as snowmobiles and ultralights. The electric glider market is much more immature..

That immaturity means they have a lot of promise, compared to the ICE gliders. We know in 5
years the performance of the electrics will increase significantly; the fossil fueled ones -
not nearly so much. Even at the current immature stage, they are so desirable, all the major
manufacturers, and some of the second tier, offer at least two electric models in mast or FES
varieties.

I suggest that in maybe 5, but certainly in 10 years, the discussions will no longer be about
gas vs electric, but which electric to buy.
--

yhttps://sites.google.com/site/motorgliders/publications/download-the-guide-1

Wishful thinking duly noted. The development, deployment and long-term flight experience of aircraft takes time. Ten years is a good estimate for a single model such as the Antares. Its first flight was in 2003, so development must have started about 20 years ago. I think that in 5 to 10 years we will be thinking "Boy, those electric gliders looked promising at the time, but if we knew then what we know now I would never have bought one." Successful product development just can't be rushed.

It's not wishful thinking when there are four companies selling electric glider power systems:
Lange, Solo, Pipistrel, and LZ Design (FES). The glider manufacturers do not have to design
their own system, like Antares had to. That speeds development (even eliminates it in some
cases), reduces their cost, and increases reliability.

While the glider market is very small, the main component - batteries - is under intense
development by major corporations around the world. We will benefit from this investment,
without investing a dime in it.

As for glider pilots feeling sorry for their current electric choices in 5 or 10 years, well,
I'm going to suggest many glider pilots will be feeling sorry for their current gas engine
choices ;^)
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1


Predicting the future is ALWAYS wishful thinking. If you could actually do it reliably you would be a billionaire. Having four companies doing it doesn't mean the development is 4 times as fast, you just get 4 possible failures instead of one.

There are already some pieces of "common wisdom" that have been debunked. One is that electric is inherently more reliable than ICE. The fire incidents are of greatest concern. Dave's issues with his Antares are also troubling - systems that are dependent on complex software can have failure modes that are only found by extensive testing. I know of another Antares owner who had to fly a technician over from Germany to fix the problems with his glider. And the small numbers of electric gliders means that buyers will ultimately do most of the testing themselves. Long term support of these complex systems is yet another question.
  #59  
Old March 5th 21, 05:57 PM posted to rec.aviation.soaring
BobW
external usenet poster
 
Posts: 504
Default $1 billion BMS Ooops...

Predicting the future is ALWAYS wishful thinking. If you could actually do
it reliably you would be a billionaire. Having four companies doing it
doesn't mean the development is 4 times as fast, you just get 4 possible
failures instead of one.



Yogi Berra - many laughed at him - was right. (Look up his body of work
involving malapropic wisdoms...you'll know when you've found the appropriate
one for this particular bit of thread drift!) Perhaps tellingly, he never
became a billionaire.

Who knows - he mighta been a decent soaring pilot!
  #60  
Old March 5th 21, 06:05 PM posted to rec.aviation.soaring
Hank Nixon
external usenet poster
 
Posts: 60
Default $1 billion BMS Ooops...

On Friday, March 5, 2021 at 11:29:30 AM UTC-5, 2G wrote:
On Thursday, March 4, 2021 at 8:22:34 AM UTC-8, Eric Greenwell wrote:
2G wrote on 3/3/2021 6:11 PM:
On Tuesday, March 2, 2021 at 8:27:55 PM UTC-8, Eric Greenwell wrote:
2G wrote on 3/2/2021 7:25 PM:
On Tuesday, March 2, 2021 at 6:28:27 PM UTC-8, Andrzej Kobus wrote:
On Tuesday, March 2, 2021 at 4:10:48 PM UTC-5, ProfJ wrote:
On Wednesday, 24 February 2021 at 14:42:01 UTC-7, wrote:
https://insideevs.com/news/490300/hy...ll-82000-bevs/
Discus amongst yourselves...
Some comments:

- High current draw for VTO launches (Lilium) - IIRC they are planning to use supercapacitors to provide the current boost so that the batteries don't have to. A supercapacitor/LiPo combination makes a lot of sense for that problem.

- Electric vs. gas: a very experienced motorglider ferry pilot, who I am sure does not want to be named, once told me when discussing Stemmes: "I've had every known Stemme issue except the in-flight fire, I'm not looking forward to that one..." I side with Eric here - we have normalized all the hassle that goes with gas self-launchers. When we get mature technology electric self-launchers, they'll dominate. Current complaints about electric sound exactly like the complaints about electric cars, before Tesla got it right.
So how big is the electric glider market vs. electric car market? Things get done with proper research and funding. I don't see that happen for the glider market. I suggest you review David's presentation. He discussed this point.

ICO glider engines have been developed over the last 70 years or so.. And, then, many of them have come from the 2-cycle engine applications such as snowmobiles and ultralights. The electric glider market is much more immature..

That immaturity means they have a lot of promise, compared to the ICE gliders. We know in 5
years the performance of the electrics will increase significantly; the fossil fueled ones -
not nearly so much. Even at the current immature stage, they are so desirable, all the major
manufacturers, and some of the second tier, offer at least two electric models in mast or FES
varieties.

I suggest that in maybe 5, but certainly in 10 years, the discussions will no longer be about
gas vs electric, but which electric to buy.
--

yhttps://sites.google.com/site/motorgliders/publications/download-the-guide-1

Wishful thinking duly noted. The development, deployment and long-term flight experience of aircraft takes time. Ten years is a good estimate for a single model such as the Antares. Its first flight was in 2003, so development must have started about 20 years ago. I think that in 5 to 10 years we will be thinking "Boy, those electric gliders looked promising at the time, but if we knew then what we know now I would never have bought one." Successful product development just can't be rushed.

It's not wishful thinking when there are four companies selling electric glider power systems:
Lange, Solo, Pipistrel, and LZ Design (FES). The glider manufacturers do not have to design
their own system, like Antares had to. That speeds development (even eliminates it in some
cases), reduces their cost, and increases reliability.

While the glider market is very small, the main component - batteries - is under intense
development by major corporations around the world. We will benefit from this investment,
without investing a dime in it.

As for glider pilots feeling sorry for their current electric choices in 5 or 10 years, well,
I'm going to suggest many glider pilots will be feeling sorry for their current gas engine
choices ;^)
--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

Predicting the future is ALWAYS wishful thinking. If you could actually do it reliably you would be a billionaire. Having four companies doing it doesn't mean the development is 4 times as fast, you just get 4 possible failures instead of one.

There are already some pieces of "common wisdom" that have been debunked. One is that electric is inherently more reliable than ICE. The fire incidents are of greatest concern. Dave's issues with his Antares are also troubling - systems that are dependent on complex software can have failure modes that are only found by extensive testing. I know of another Antares owner who had to fly a technician over from Germany to fix the problems with his glider. And the small numbers of electric gliders means that buyers will ultimately do most of the testing themselves. Long term support of these complex systems is yet another question.


You can't buy experience, but you do pay for it!
UH
 




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