Which sustainer system would you chose for your sailplane?

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