Jet engines vs. leaf blowers

I am bored with all the current threads on the newsgroup.



Larry

O'K...are we ready for our annual World Class PW-5 glider discussion or
we wait 'till after the soaring season? I am surre this one would not
be boring.

I think the PW5 thread is traditionally in the fall. It's a bit early
in the year to start. We could however try to conger up lennie from the
dark side. Anyone know a good magus? Lennie was always good for some
long purposeless threads.

I was sorta curious about the jet engines versus leaf-blowers thing.
What'd I miss?

How about warming up the old 'battery charging' discussion. That
ususally sparks some interesting comments..

Good idea, Uli. I will take it from here. On a slightly
different bent. Join in, if you like. Pretend this
is being said by Andy Rooney of 60 Minutes.

Ever wonder why all these glider pilots want to install
not one, not two, but three or four seperate 12 volt
batteries in their gliders? I have for years operated
with just ONE 14 volt, 10 amp hour battery. Never
had it die on me in flight. Of course, I don't fly
as long each day as Klaus Ohlman or Gordon Boettger...

See this from my partner:

Canopy & Gear Door leakage control
=AB Start of topic =AB Older Messages 1 - 10 of 25 Newer =BB End
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1. Ken Kochanski \"Kilo Kilo\" Sep 9 1997, 3:00 am show
options

Newsgroups: rec.aviation.soaring
From: "Ken Kochanski \"Kilo Kilo\"" - Find
messages by this author
Date: 1997/09/09
Subject: Canopy & Gear Door leakage control
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Like most other glider pilots, I know that leakage around the canopy
and
gear doors is a major are of performance loss ... and I have installed
the standard set of open and closed cell foam seals in an attempt to
control this problem. I have always suspected the mechanicals were
not
performing properly, however, and eventually realized that proper
pressure control inside the fuseladge was the only way to stop the
leakage. Some rough calculations indicated that a sustained pressure
drop .2 inches of mercury would be required. Since this decrease
could not be achieved using aome arrangement of NACA ducts on the
fuseladge, a solution using some type of powered means (i.e. fan or
blower) was sought. Solar powered exaust fans for trailer ventilation
proved to be too weak and a search of trade publications (air
conditioning, environmental controls, etc.) did not uncover any real
solutions, since all were powered by AC motors. Quite by accident, I
discovered that I had a device capable of generating enough suction
right in my garage ... in the form of a Stihl BG72 (72 cc) leaf
blower. The unit was actually a little too big, which created a few
engineering problems explained below. A set of brackets were
fabricated and the unit was mounted in the tail boom of my ASW-20B just

behind the mixer. A simple set of controls were fabricated to start,
throttle, and shut down the engine. We extended the blower nozzle to
exhaust through the opening just below the rudder ... just to insure
all
combustion products were properly expelled from the cockpit environ.
Since the unit was actually a little larger than desired, cooling
became
a bit of a problem, and we had to put NACA ducts in the gear doors and
the top of the fuse to supply more air to the engine. Eventually we
got
the balance correct and a manometer reading indicated that the cockpit
pressure would drop .3" hg at sea level when the engine was running
at
full throttle on he ground. Since the installation took so long, I
did
not have an opportunity to perform any flight tests prior to leaving
for
the Region III contest at Elmira. Starting the unit in the air proved
to be more of a problem than anticipated, and the poor weather at the
meet made it impossible to conduct many extensive side-by-side glide
comparisons against the new ASW-27s and V2s. However, on the last day
I
was in a final glide with SM (ASW-27) and I managed to get the blower
running. The performace improvement was immediately apparent ... and I

would estimate that my glide ratio was equal to ... or perhaps better
than ... the ASW-27. Unfortunately, SM hit the ground 9 miles out and
I
luckily made it home. Controlling cockpit and gear door leakage
clearly
has more of a performance improvement that the the winglets installed 6

years ago ... and base unit only costs 149.00 USD. I hope to have all

the bugs worked out before the Sports Class Nationals next Spring. See

you there ... Good luck and good racing!!!


2. Uwe Hale Sep 9 1997, 3:00 am show options

Newsgroups: rec.aviation.soaring
From: Uwe Hale - Find messages by this author
Date: 1997/09/09
Subject: Canopy & Gear Door leakage control
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Hi Ken,



Since this decrease
could not be achieved using aome arrangement of NACA ducts on the
fuseladge, a solution using some type of powered means (i.e. fan or
blower) was sought. Solar powered exaust fans for trailer ventilation
proved to be too weak and a search of trade publications (air
conditioning, environmental controls, etc.) did not uncover any real
solutions, since all were powered by AC motors. ...


Check out the ducted fans and electric DC motors used to power RC jet
airplanes. They might require a large battery if you plan on running
it for
the entire flight. I recently read that NASCAR type folks are using
them for
cooling driver and brakes.


Quite by accident, I
discovered that I had a device capable of generating enough suction
right in my garage ... in the form of a Stihl BG72 (72 cc) leaf
blower.


..=2E

Yikes! Sounds scary. I bet if you mount that in the nose, put a prop
on it,
and use it as a sustainer, you will get even better performance than
using it
to deal with leaks.


=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D
Uwe Hale
http://www.sct-inc.com


Texas Soaring Association
http://www.txcc.net/~perkinsd/texsoar/
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D


3. David Leonard Sep 9 1997, 3:00 am show options

Newsgroups: rec.aviation.soaring
From: David Leonard - Find messages by this
author
Date: 1997/09/09
Subject: Canopy & Gear Door leakage control
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| Report Abuse


Ken Kochanski "Kilo Kilo" wrote:




- Hide quoted text -
- Show quoted text -

Like most other glider pilots, I know that leakage around the canopy
and
gear doors is a major are of performance loss ... and I have installed

the standard set of open and closed cell foam seals in an attempt to
control this problem. I have always suspected the mechanicals were
not
performing properly, however, and eventually realized that proper
pressure control inside the fuseladge was the only way to stop the
leakage. Some rough calculations indicated that a sustained pressure
drop .2 inches of mercury would be required. Since this decrease
could not be achieved using aome arrangement of NACA ducts on the
fuseladge, a solution using some type of powered means (i.e. fan or
blower) was sought. Solar powered exaust fans for trailer ventilation


proved to be too weak and a search of trade publications (air
conditioning, environmental controls, etc.) did not uncover any real
solutions, since all were powered by AC motors. Quite by accident, I


discovered that I had a device capable of generating enough suction
right in my garage ... in the form of a Stihl BG72 (72 cc) leaf
blower. The unit was actually a little too big, which created a few
engineering problems explained below. A set of brackets were
fabricated and the unit was mounted in the tail boom of my ASW-20B
just
behind the mixer. A simple set of controls were fabricated to start,
throttle, and shut down the engine. We extended the blower nozzle to
exhaust through the opening just below the rudder ... just to insure
all
combustion products were properly expelled from the cockpit environ.
Since the unit was actually a little larger than desired, cooling
became
a bit of a problem, and we had to put NACA ducts in the gear doors and


the top of the fuse to supply more air to the engine. Eventually we
got
the balance correct and a manometer reading indicated that the cockpit


pressure would drop .3" hg at sea level when the engine was running at


full throttle on he ground. Since the installation took so long, I
did
not have an opportunity to perform any flight tests prior to leaving
for
the Region III contest at Elmira. Starting the unit in the air proved


to be more of a problem than anticipated, and the poor weather at the
meet made it impossible to conduct many extensive side-by-side glide
comparisons against the new ASW-27s and V2s. However, on the last day
I
was in a final glide with SM (ASW-27) and I managed to get the blower
running. The performace improvement was immediately apparent ... and
I
would estimate that my glide ratio was equal to ... or perhaps better


than ... the ASW-27. Unfortunately, SM hit the ground 9 miles out and
I
luckily made it home. Controlling cockpit and gear door leakage
clearly
has more of a performance improvement that the the winglets installed
6
years ago ... and base unit only costs 149.00 USD. I hope to have
all
the bugs worked out before the Sports Class Nationals next Spring.
See
you there ... Good luck and good racing!!!



Isn't that kind of like a ducted fan? Intake in gear door scoops,
output
in tail. Sounds like a weak motor-glider to me. It would take very
little thrust to give you a visible performance difference. Much more
likely you're getting a bit of thrust than significant drag reduction.
Definitely raises interesting question for competition rules.

-Dave Leonard
AS-W20 ZL


4. David Leonard Sep 9 1997, 3:00 am show options

Newsgroups: rec.aviation.soaring
From: David Leonard - Find messages by this
author
Date: 1997/09/09
Subject: Canopy & Gear Door leakage control
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Ken Kochanski "Kilo Kilo" wrote:
snip...



Controlling cockpit and gear door leakage clearly
has more of a performance improvement that the the winglets installed
6
years ago ... and base unit only costs 149.00 USD. I hope to have
all
the bugs worked out before the Sports Class Nationals next Spring.
See
you there ... Good luck and good racing!!!


Let's see, a bigger unit could turn your wing blow holes into suck
holes, which work better anyway, then you could probably out glide a
Nimbus 4 with the old 20B ;-)

ZL


5. FSD NetSrv Sep 10 1997, 3:00 am show options

Newsgroups: rec.aviation.soaring
From: FSD NetSrv - Find messages by this author

Date: 1997/09/10
Subject: Canopy & Gear Door leakage control
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Come on, Ken! You wrote that as a tongue-in-cheek attempt
to raise some controversy, didn't you? 'Fess up now.
I was laughing the whole time that I read it, thinking to myself:
"you know, somebody is going to think he is serious and start
writing in that this is not cockpit sealing, but is clearly a
ducted fan form of powered propulsion."


And I disagree with the other post that suggests a propellor on
the nose would work better. For something as sleek as a 20,
ducted fan propulsion is the way to go, unless you want to
use the engine for takeoff.
Elmer Mooring (T8)



Ken wrote:


We extended the blower nozzle to


- Hide quoted text -
- Show quoted text -

exhaust through the opening just below the rudder ... just to insure
all
combustion products were properly expelled from the cockpit environ.
Since the unit was actually a little larger than desired, cooling
became
a bit of a problem, and we had to put NACA ducts in the gear doors and
the top of the fuse to supply more air to the engine.


6. news_check.py Sep 10 1997, 3:00 am show options

Newsgroups: rec.aviation.soaring
From: (news_check.py) - Find messages by this
author
Date: 1997/09/10
Subject: Canopy & Gear Door leakage control
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In article "Ken Kochanski \"Kilo Kilo\""
wrote:



Like most other glider pilots, I know that leakage around the canopy and
gear doors is a major are of performance loss ... and I have installed
the standard set of open and closed cell foam seals in an attempt to


Like most other glider pilots, I know that leakage around the canopy
and
gear doors is a major are of performance loss ... and I have installed
the standard set of open and closed cell foam seals in an attempt to
control this problem. I have always suspected the mechanicals were
not
performing properly, however, and eventually realized that proper
pressure control inside the fuseladge was the only way to stop the
leakage. Some rough calculations indicated that a sustained pressure
drop .2 inches of mercury would be required. Since this decrease
could not be achieved using aome arrangement of NACA ducts on the
fuseladge, a solution using some type of powered means (i.e. fan or
blower) was sought. Solar powered exaust fans for trailer ventilation
proved to be too weak and a search of trade publications (air
conditioning, environmental controls, etc.) did not uncover any real
solutions, since all were powered by AC motors. Quite by accident, I
discovered that I had a device capable of generating enough suction
right in my garage ... in the form of a Stihl BG72 (72 cc) leaf
blower. The unit was actually a little too big, which created a few
engineering problems explained below. A set of brackets were
fabricated and the unit was mounted in the tail boom of my ASW-20B just

behind the mixer. A simple set of controls were fabricated to start,
throttle, and shut down the engine. We extended the blower nozzle to
exhaust through the opening just below the rudder ... just to insure
all
combustion products were properly expelled from the cockpit environ.
Since the unit was actually a little larger than desired, cooling
became
a bit of a problem, and we had to put NACA ducts in the gear doors and
the top of the fuse to supply more air to the engine. Eventually we
got
the balance correct and a manometer reading indicated that the cockpit
pressure would drop .3" hg at sea level when the engine was running
at
full throttle on he ground. Since the installation took so long, I
did
not have an opportunity to perform any flight tests prior to leaving
for
the Region III contest at Elmira. Starting the unit in the air proved
to be more of a problem than anticipated, and the poor weather at the
meet made it impossible to conduct many extensive side-by-side glide
comparisons against the new ASW-27s and V2s. However, on the last day
I
was in a final glide with SM (ASW-27) and I managed to get the blower
running. The performace improvement was immediately apparent ... and I

would estimate that my glide ratio was equal to ... or perhaps better
than ... the ASW-27. Unfortunately, SM hit the ground 9 miles out and
I
luckily made it home. Controlling cockpit and gear door leakage
clearly
has more of a performance improvement that the the winglets installed 6

years ago ... and base unit only costs 149.00 USD. I hope to have all

the bugs worked out before the Sports Class Nationals next Spring. See

you there ... Good luck and good racing!!!

7. CloudSippr Sep 11 1997, 3:00 am show options

Newsgroups: rec.aviation.soaring
From: (CloudSippr) - Find messages by this author
Date: 1997/09/11
Subject: Canopy & Gear Door leakage control
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seems to me that perhaps the extra performance was caused more by
sucking
air in the front and expelling it out the back - I bet someone clever
could
spray kerosene ... and add a torch at the back ...g


8. Uwe Hale Sep 10 1997, 3:00 am show options

Newsgroups: rec.aviation.soaring
From: Uwe Hale - Find messages by this author
Date: 1997/09/10
Subject: Canopy & Gear Door leakage control
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Hi Rod,



And I disagree with the other post that suggests a propellor on
the nose would work better. For something as sleek as a 20,
ducted fan propulsion is the way to go, unless you want to
use the engine for takeoff.


I figured if he was serious enough about efficiency to go through all
the
trouble that he did, that he would want the increased efficiency of a
prop over
a ducted fan.

Also, instead of putting intake ducts in the gear doors, they should
all be on
the top side so that the glider gets "sucked" into the air.g


Hmm - the mind reels. Get several more blowers, put the exhaust duct
near the
CG facing down and you could have a STOL or Harrier type aircraft. ;-)


Why do I get the feeling this would make an ideal post for early in
April?


=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D
Uwe Hale
http://www.sct-inc.com


Texas Soaring Association
http://www.txcc.net/~perkinsd/texsoar/
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D


9. FSD NetSrv Sep 10 1997, 3:00 am show options

Newsgroups: rec.aviation.soaring
From: FSD NetSrv - Find messages by this author

Date: 1997/09/10
Subject: Canopy & Gear Door leakage control
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Because if it was April, everyone would know that he
is kidding and then it wouldn't be as much fun.
This way, some folks think it is serious and we get
a better thread.
Elmer Mooring (T8)



- Hide quoted text -
- Show quoted text -

Uwe Hale wrote:
Why do I get the feeling this would make an ideal post for early
in April?


10. Uwe Hale Sep 10 1997, 3:00 am show options

Newsgroups: rec.aviation.soaring
From: Uwe Hale - Find messages by this author
Date: 1997/09/10
Subject: Canopy & Gear Door leakage control
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Hi Rod,



Because if it was April, everyone would know that he
is kidding and then it wouldn't be as much fun.
This way, some folks think it is serious and we get
a better thread.


I was not sure how to take it at first. Like I said, it sounded pretty
scary.
But then I remember friends in high school trying to supercharge cars
by
hooking a reversed vacuum cleaner to the carburetor, or creating a poor
mans
Nitrous system by attaching a can of starter fluid(ether) to the
intake. I
thought maybe some of these guys grew up to be glider pilots.

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D
Uwe Hale
http://www.sct-inc.com


Texas Soaring Association
http://www.txcc.net/~perkinsd/texsoar/
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3 D=3D=3D=3D=3D=3D



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