Which sustainer system would you chose for your sailplane?

When is a hybrid coming? FES plus a 10hp generator would be the ideal combination.

On Friday, January 8, 2016 at 3:53:32 PM UTC+3, J. Nieuwenhuize wrote:
When is a hybrid coming? FES plus a 10hp generator would be the ideal combination.

Solar cells.

It shouldn't be long before it's economic to embed solar cells under a thin smooth transparent layer (would gelcoat do?) of the entire upper surface of the wing.

At current efficiencies, a single seater with 10 sq m of wing will get about 2 hp, not 10, but that will still help as it'll be working almost all the time.

On Friday, January 8, 2016 at 1:40:33 AM UTC-5, Surge wrote:
On Thursday, 27 September 2012 00:06:31 UTC+2, wrote:
For me electrical sustainer in a glider is the perfect solution. It links in to the spirit of the sport, better than a turbine. But the propeller on the nose feels slightly off.... Especially when you consider the bugwiper garages becoming standard on the top sailplanes. We are spending more and more on reducing drag. Then this minor addition feels going against the flow. Why not a small pylon with this nice foldable propeller you have engineered? Or am I the only one who has this uncomfortable feeling?

How about FES in an EDF (electric ducted fan) configuration instead of pylon mounted FES? The EDF could be mounted in the fuselage with doors than open and close for the inlet and exhaust.
Would this make any sense or be simpler than a pylon mounted system?
Would a smaller prop size make it less efficient and impractical?
The one advantage would be the removal of most of the pitching issue associated with pylon mounted systems.

If I had the money for a self launcher or sustainer equipped glider it would be FES due to simplicity, reliability and safety.
From a safety perspective I presume a battery fire would tend to be more isolated in a crash whereas with combustible fuel you and the glider could become engulfed in flames within seconds as fuel is splashed around.
As battery and fuel cell technology advances, alternative energy storage upgrades could be a possibility without having to purchase another glider.
I don't like the smell of gasoline or jet fuel nor the complexity with things that operate at high temperatures and need to be maintained regularly. A brushless electric motor can literally run for years with a decent set of bearings. That means less hassle and maybe lower maintenance costs over the long run depending on the battery technology being used.

A sustainer option would suite me perfectly. I don't need to operate autonomously and a winch launch to 1500 feet is cheap ($4.70 USD) and preserves power for when I may need it.

With retractable gear, mixers/controls, etc., not much room for a decent sized EDF. Unless of course, you want to make the fuselage larger, but that add's wetted area and reduces the performance.

At 14:52 08 January 2016, Charlie M. UH & 002 owner/pilot
wrote:
On Friday, January 8, 2016 at 1:40:33 AM UTC-5, Surge
wrote:
On Thursday, 27 September 2012 00:06:31 UTC+2,

wrot=
e:
For me electrical sustainer in a glider is the perfect
solution. It
lin=
ks in to the spirit of the sport, better than a turbine. But
the propeller
=
on the nose feels slightly off.... Especially when you
consider the
bugwipe=
r garages becoming standard on the top sailplanes. We are
spending more
and=
more on reducing drag. Then this minor addition feels
going against the
fl=
ow. Why not a small pylon with this nice foldable propeller
you have
engine=
ered? Or am I the only one who has this uncomfortable
feeling?
=20
How about FES in an EDF (electric ducted fan)
configuration instead of
py=
lon mounted FES? The EDF could be mounted in the
fuselage with doors than
o=
pen and close for the inlet and exhaust.
Would this make any sense or be simpler than a pylon
mounted system?
Would a smaller prop size make it less efficient and
impractical?
The one advantage would be the removal of most of the
pitching issue
asso=
ciated with pylon mounted systems.
=20
If I had the money for a self launcher or sustainer
equipped glider it
wo=
uld be FES due to simplicity, reliability and safety.
From a safety perspective I presume a battery fire would
tend to be more
=
isolated in a crash whereas with combustible fuel you and
the glider could
=
become engulfed in flames within seconds as fuel is
splashed around.
As battery and fuel cell technology advances, alternative
energy storage
=
upgrades could be a possibility without having to purchase
another glider.
I don't like the smell of gasoline or jet fuel nor the
complexity with
th=
ings that operate at high temperatures and need to be
maintained
regularly.=
A brushless electric motor can literally run for years with a
decent set
o=
f bearings. That means less hassle and maybe lower
maintenance costs over
t=
he long run depending on the battery technology being
used.
=20
A sustainer option would suite me perfectly. I don't need
to operate
auto=
nomously and a winch launch to 1500 feet is cheap ($4.70
USD) and
preserves=
power for when I may need it.

With retractable gear, mixers/controls, etc., not much room
for a decent
si=
zed EDF. Unless of course, you want to make the fuselage
larger, but that
a=
dd's wetted area and reduces the performance.


I'd agree with most of the above: gasoline is certainly a
hazard in a crash but Lithium batteries are not exactly "safe"
in a crash, they too can burn and the combustion products
are very hazardous. Then there's the problem of several
hundred volts DC at large...
See:
http://www.bea.aero/fr/enquetes/2012/2012.semaine.36.pd
f

As a very proud of e very nice Lak17a, I asked Luka for the price of FES Retrofit.
Answer was quick, contact very nice.

Price was not.

I sold the Lak and bought an ASH25e.

Which sustainer system would you chose for your SAILPLANE?

Experience and skill.

If I wanted and aeroplane, I would have a ASH 31Mi or and Arcus M.

Fine if you want to never stretch the day, and enjoy landing in places
where unforeseen risks/hidden obstacles can cause expensive damage.

I have landed in more fields than I care to remember, and occasionally
beaten World Champions on competition tasks. I feel no shame in
knowing when the day is over and ending back at the field with an
intact ship ready for the next day.

Chacun a son gout.

At 15:37 11 January 2016, Justin Craig wrote:

Which sustainer system would you chose for your SAILPLANE?

Experience and skill.

If I wanted and aeroplane, I would have a ASH 31Mi or and Arcus M.

On Thursday, January 7, 2016 at 10:40:33 PM UTC-8, Surge wrote:

How about FES in an EDF (electric ducted fan) configuration instead of pylon mounted FES? The EDF could be mounted in the fuselage with doors than open and close for the inlet and exhaust.
Would this make any sense or be simpler than a pylon mounted system?
Would a smaller prop size make it less efficient and impractical?
The one advantage would be the removal of most of the pitching issue associated with pylon mounted systems.


FES is by definition the front mounted ('F') variety not pylon mounted - just to nit-pick.

As to EDF, you might be able to get one big enough to climb a glider, but the efficiencies would, I suspect, be poor and electric sustainers already face a weight/range tradeoff that is marginal for many pilots. I expect the pylon-mounted sustainers with a larger prop would be the best compromise (reliable and fast deployment, minimal drag, acceptable range, low enough weight for an 18m glider to not face too much of a weight penalty. Whether it is appreciably more efficient than an FES prop would be interesting to know - my guess is they'd be a bit more efficient. FES wins for pure simplicity..

I'd rather carry batteries around than gasoline any day. Internal combustion engines (and turbines) are a recipe for lots of mechanical fiddling and maintenance in my experience.

9B

On Tuesday, January 12, 2016 at 3:16:41 PM UTC-5, Andy Blackburn wrote:
On Thursday, January 7, 2016 at 10:40:33 PM UTC-8, Surge wrote:

How about FES in an EDF (electric ducted fan) configuration instead of pylon mounted FES? The EDF could be mounted in the fuselage with doors than open and close for the inlet and exhaust.
Would this make any sense or be simpler than a pylon mounted system?
Would a smaller prop size make it less efficient and impractical?
The one advantage would be the removal of most of the pitching issue associated with pylon mounted systems.


FES is by definition the front mounted ('F') variety not pylon mounted - just to nit-pick.

As to EDF, you might be able to get one big enough to climb a glider, but the efficiencies would, I suspect, be poor and electric sustainers already face a weight/range tradeoff that is marginal for many pilots. I expect the pylon-mounted sustainers with a larger prop would be the best compromise (reliable and fast deployment, minimal drag, acceptable range, low enough weight for an 18m glider to not face too much of a weight penalty. Whether it is appreciably more efficient than an FES prop would be interesting to know - my guess is they'd be a bit more efficient. FES wins for pure simplicity.

I'd rather carry batteries around than gasoline any day. Internal combustion engines (and turbines) are a recipe for lots of mechanical fiddling and maintenance in my experience.

9B

There are plenty of retractable engine gliders that, due to geometry changes to fit the engine etc, and/or poor doors, may well have as much drag rise over a pure glider as those 2 prop blades.
The down side to front motor is that, for almost all but the light gliders, there is not a good way to get enough ground clearance for a prop that will apply the power needed for self launch.
It is a very clever concept.
UH

On 12/01/2016 22:16, Andy Blackburn wrote:

I expect the pylon-mounted sustainers with a larger prop
would be the best compromise (reliable and fast deployment, minimal
drag, acceptable range, low enough weight for an 18m glider to not
face too much of a weight penalty. Whether it is appreciably more
efficient than an FES prop would be interesting to know - my guess is
they'd be a bit more efficient. FES wins for pure simplicity.

If I were investing in a sustainer, my preference would also be for a
pylon mounted electric unit. Pylon retraction should be as reliable as
u/c retraction and time to extend/retract would not equate to
significant hight loss. Once the prop is in the breeze an electric drive
is equally reliable on a pylon as it is on a FES.

Pylon installation in existing fuselage designs should be easier than
FES and there would be fewer complications with cooling and instruments.
When a pylon motor is stowed, there is less drag than there is with a
folding prop and unlike FES there is very little chance of accidental
damage.

I am not sure what the drag/efficiency is of a FES verses a pylon +
large prop once they are both running. Maybe FES has an advantage,
giving it longer range?

I'd rather carry batteries around than gasoline any day. Internal
combustion engines (and turbines) are a recipe for lots of mechanical
fiddling and maintenance in my experience.

I think the biggest requirement for a sustainer is reliable starting,
with minimum pilot work load and minimum hight loss. Electric has got to
win every time.

Now if FES technology and experience was to put into a pylon mounted
electric sustainer which could be retrofitted it into any 15m or 18m
fuselage originally designed to accommodate a sustainer, I might be
tempted to pawn my pension....

The tricky part is that the batteries may have to go into the wings.

Ian