Today's Message Index:
----------------------
1. 12:43 AM - Re: Re: Votex Generators (Keith Hickling)
2. 01:39 AM - Re: paint shops (Alan)
3. 02:34 AM - Re: Votex Generators (flyingphil2)
4. 07:42 AM - paint shop (danny@mcwalterscafe.co.uk)
5. 08:12 AM - Re: Votex Generators (Fred Klein)
6. 08:21 AM - Re: Re: Votex Generators (D.Hetrick)
7. 08:34 AM - Re: Votex Generators (D.Hetrick)
8. 09:15 AM - Re: Votex Generators (flyingphil2)
9. 09:19 AM - Re: Re: Votex Generators ()
10. 10:41 AM - Re: Votex Generators (rampil)
11. 10:57 AM - Re: Votex Generators (Graham Singleton)
12. 02:05 PM - Re: Re: Votex Generators (Graham Singleton)
13. 02:09 PM - Re: Votex Generators (karelvranken)
14. 03:05 PM - Re: Re: Votex Generators (Fred Klein)
15. 04:37 PM - Airbrake horn cover ()
16. 04:52 PM - Re: Re: Votex Generators (Graham Singleton)
Message 1
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Subject: | Re: Votex Generators |
Do they increase drag at higher speeds?
Keith Hickling.
----- Original Message -----
From: "D.Hetrick" <gdh@isp.com>
Sent: Friday, May 11, 2007 1:18 PM
Subject: Re: Europa-List: Re: Votex Generators
>
> Fred,
> I.m told that the VG's can ruduce the stall speeds by as much as 12 mph,
> aircraft dependable of course.
> I'm thinking seriously of giving it a try.
> Dale
> ----- Original Message -----
> From: "Fred Klein" <fklein@orcasonline.com>
> To: <europa-list@matronics.com>
> Sent: Thursday, May 10, 2007 5:53 PM
> Subject: Re: Europa-List: Re: Votex Generators
>
>
>>
>>
>> On Thursday, May 10, 2007, at 02:41 PM, Graham Singleton wrote:
>>
>>> VGs were applied to the wing and canard of a Long EZ, which has laminar
>>> sections on both, to reduce stall speed, the VGs re energise the laminar
>>> boundary layer and help to prevent separation after the max thickness
>>> point of the section. Stall was reduced by 7 kts.
>>> Graham
>>
>> So here's a question...
>>
>> Is it conceivable that adding VGs to the Europa could reduce the stall
>> speed sufficiently to meet the LSA requirements?
>>
>>
>>
>>
>>
>>
>
>
>
Message 2
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Murray Flint in Norfolk did my tri gear early this year. He paints millions
of Jabirus and has done a few Europas.
When I shopped around his name was repeatedly recommended and I'm very
pleased with the job he's done.
murray@flint.flyer.co.uk 01945 780023
Alan
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Richard
Collings
Sent: 10 May 2007 18:00
Subject: Re: Europa-List: paint shops
<r.collings@onetel.net>
It may seem a long way to go but you couldn't do much better than Mick Allen
& Sons Ltd . Turweston Airfield, Brackley, Northants. They are in a purpose
built building right next door to the PFA offices.
----- Original Message -----
From: <danny@mcwalterscafe.co.uk>
Sent: Thursday, May 10, 2007 10:02 AM
Subject: Europa-List: paint shops
> <danny@mcwalterscafe.co.uk>
>
> Hi All,
> My baby is getting very close to being ready to be painted. Can
> anyone in the uk recommend a good paint shop. I reside in north wales,
> but will be able to trail R.I. any where in the uk.
>
> Cheers Danny G-c.e.r.i.
>
>
> --
> 269.6.6/795 - Release Date: 5/9/2007 15:07
>
>
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Message 3
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Subject: | Re: Votex Generators |
This is developing into quite a discussion. I'm an aerodynamicist by trade and
so here's my answers to the points above:
1. If someone wants to try VGs on a Europa then go ahead but I suspect they won't make any difference. The wing design is far more advanced than those seen on www.landshorter.com which tend to be things like the Kitfox etc. VGs may improve flow over the ailerons which will make the aircraft feel better at slow speeds and will improve controllability near the stall. With a poor wing design they may reduce the stall speed. Don Dykins used a lot of his (and his department's) experience in the Europa wing and that was previously used on aircraft like the BAe 146 and early Airbus.
2. Graham is right about the Long Eze and the way in which the VGs helped. I
guess the laminar region on the canards was probably the first 25% of the chord
and there was a trailing edge separation. The Europa is designed to have a
larger laminar region with no separation and so the VGs will not help in this
case.
3. To reduce the stall speed on the Europa you would need to have a more powerful
flap with maybe an additional 'flap vane' ahead of the main flap or something
like leading edge slats. You could try a 'blown' wing as well if you were
keen.
On another point:
NACA intakes are designed to be an efficient and low drag intake method. The edges
of the intake generate small vortices which the flow down the intake and
they work very well indeed if positioned in the right place. I think Duncan's
issue may be down to a positioning problem and you won't improve the flow down
that duct with a VG at high aoa if the flow isn't going that way in the first
place. That brings me on to another point. I routinely run large computer
simulations of external aerodynamic cases in my job. I'm quite keen to look at
a Europa but need some CAD geometry. The factory doesn't have any as the moulds
were hand made so my question is has anyone, who has too much spare time
on their hands, made a good quality CAD representation of a Europa? I know there
are some models floating round for flight simulators but they are far too
basic for what I would need.
Regards,
Phil
Visit - www.EuropaOwners.org
Message 4
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Thanks for all the recommendations. Time to start making a few phone call.
Cheers Danny
Message 5
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Subject: | Re: Votex Generators |
Phil,
The resourceful minds plugged into this forum never cease to amaze
me...thanks for sharing your knowledge of VGs.
Would you care to opine as to the aerodynamics of the
wingroot/flap/fuselage intersection and what might be done to reduce
drag in this area?
Fred
A194
On Friday, May 11, 2007, at 02:33 AM, flyingphil2 wrote:
>
> I'm an aerodynamicist by trade and so here's my answers to the points
> above:
Message 6
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Subject: | Re: Votex Generators |
Keith,
Not according to their information.
Dale
----- Original Message -----
From: "Keith Hickling" <keithhickling@clear.net.nz>
Sent: Thursday, May 10, 2007 7:41 PM
Subject: Re: Europa-List: Re: Votex Generators
> <keithhickling@clear.net.nz>
>
> Do they increase drag at higher speeds?
>
> Keith Hickling.
>
> ----- Original Message -----
> From: "D.Hetrick" <gdh@isp.com>
> To: <europa-list@matronics.com>
> Sent: Friday, May 11, 2007 1:18 PM
> Subject: Re: Europa-List: Re: Votex Generators
>
>
>>
>> Fred,
>> I.m told that the VG's can ruduce the stall speeds by as much as 12 mph,
>> aircraft dependable of course.
>> I'm thinking seriously of giving it a try.
>> Dale
>> ----- Original Message -----
>> From: "Fred Klein" <fklein@orcasonline.com>
>> To: <europa-list@matronics.com>
>> Sent: Thursday, May 10, 2007 5:53 PM
>> Subject: Re: Europa-List: Re: Votex Generators
>>
>>
>>>
>>>
>>> On Thursday, May 10, 2007, at 02:41 PM, Graham Singleton wrote:
>>>
>>>> VGs were applied to the wing and canard of a Long EZ, which has laminar
>>>> sections on both, to reduce stall speed, the VGs re energise the
>>>> laminar boundary layer and help to prevent separation after the max
>>>> thickness point of the section. Stall was reduced by 7 kts.
>>>> Graham
>>>
>>> So here's a question...
>>>
>>> Is it conceivable that adding VGs to the Europa could reduce the stall
>>> speed sufficiently to meet the LSA requirements?
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>
>
>
Message 7
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Subject: | Re: Votex Generators |
Phil,
Thank you very much for your insight on VG's. Guess I had better wait until
after you run your simulations before adding them.
Thanks again,
Dale
----- Original Message -----
From: "flyingphil2" <ptiller@lolacars.com>
Sent: Friday, May 11, 2007 2:33 AM
Subject: Re: Europa-List: Votex Generators
>
> This is developing into quite a discussion. I'm an aerodynamicist by
> trade and so here's my answers to the points above:
>
> 1. If someone wants to try VGs on a Europa then go ahead but I suspect
> they won't make any difference. The wing design is far more advanced than
> those seen on www.landshorter.com which tend to be things like the Kitfox
> etc. VGs may improve flow over the ailerons which will make the aircraft
> feel better at slow speeds and will improve controllability near the
> stall. With a poor wing design they may reduce the stall speed. Don
> Dykins used a lot of his (and his department's) experience in the Europa
> wing and that was previously used on aircraft like the BAe 146 and early
> Airbus.
>
> 2. Graham is right about the Long Eze and the way in which the VGs
> helped. I guess the laminar region on the canards was probably the first
> 25% of the chord and there was a trailing edge separation. The Europa is
> designed to have a larger laminar region with no separation and so the VGs
> will not help in this case.
>
> 3. To reduce the stall speed on the Europa you would need to have a more
> powerful flap with maybe an additional 'flap vane' ahead of the main flap
> or something like leading edge slats. You could try a 'blown' wing as
> well if you were keen.
>
> On another point:
>
> NACA intakes are designed to be an efficient and low drag intake method.
> The edges of the intake generate small vortices which the flow down the
> intake and they work very well indeed if positioned in the right place. I
> think Duncan's issue may be down to a positioning problem and you won't
> improve the flow down that duct with a VG at high aoa if the flow isn't
> going that way in the first place. That brings me on to another point. I
> routinely run large computer simulations of external aerodynamic cases in
> my job. I'm quite keen to look at a Europa but need some CAD geometry.
> The factory doesn't have any as the moulds were hand made so my question
> is has anyone, who has too much spare time on their hands, made a good
> quality CAD representation of a Europa? I know there are some models
> floating round for flight simulators but they are far too basic for what I
> would need.
>
> Regards,
>
> Phil
>
>
> Visit - www.EuropaOwners.org
>
>
>
Message 8
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Subject: | Re: Votex Generators |
Hi Fred,
Well my thoughts on this would be as follows:
1. Is there a problem in that area? Oil flow tests would show up any separations
in that area or maybe someone with a dirty aircraft has flown through rain
and has some pictures of the surface flow patterns that were left. If there
is no obvious problem then I'd leave it alone.
2. If there is a problem then making a really good job of the wing fillets would
be the best approach and maybe trying to maximise the radius of that fillet
(larger radius = better). The problem with a large radius is what happens when
you come to the trailing edge of the wing (or in the Europa's case, where the
wing ends and the flap starts). You need to lose that large radius and run
it out to nothing smoothly.
3. Sealing the wing against the fuselage would definitely be good. On gliders,
we use PVC tape but that only works if you have a small 'wing stub' moulded
into the fuselage that the wing butts up to. On a Europa I would say that some
high density foam on the inside of the wing root fillet would do the trick and
when the wings are fitted, the foam is compressed and thus forms a nice seal.
I.m not sure what gaps people have between the fuselage and the wing fillets
but try and keep them as small as possible.
In terms of drag reduction I would have thought that there is little to do on the
Europa. It's already an excellent design and the use of composite materials
(and ability to build almost any shape) helps this. Compared to some homebuilts
on the market using the same engine, it has to be a very efficient machine.
Having said that, you notice the difference on a glider if the wing roots
are not taped and the controls are not sealed and so all these little bits of
attention to detail would add up and help reduce the drag that little bit further.
Actually, that's an interesting point above. Out of all the homebuilts powered
with a 912S, there can't be many aircraft that are faster than a Europa. There
is the DynAero MCR1 (which I had an amazing flight in once) and that is very
fast but look at the size of it - it's tiny. Anyone have any other comparisons?
Phil
Visit - www.EuropaOwners.org
Message 9
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Subject: | Re: Votex Generators |
A few negatives to keep in mind with Vortex generators:
Cleaning = PIA
Waxing = PIA
Painting = PIA
Another thing to break
Ron Parigoris
Message 10
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Subject: | Re: Votex Generators |
Re Conversion to LSA specs
Europa04 and Custom Flight Creations (AKA Europa USA)
currently has Bud Yerly working on a new wing design to meet
the LSA spec and be easier and less expensive.
As I noted previously in the forum, Bud is the only guy I who has a
degree in ->Low Speed
--------
Ira N224XS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=112268#112268
Message 11
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Subject: | Re: Votex Generators |
Phil
the nioest wing root I've seen is Ted and Justin's, small radius at the
LE, large at the TE. picture attached. imho this is the way to do it,
the fillet needs to be flexible to allow wing bending without crushing
the fuselage side, so no more than 3 plies of BID at the edge. There are
several Europas with this style but only Ted's has the elegant change of
radius moving aft.
Easier to rig a wing done like this too, something to line up with as it
goes in.
Graham
flyingphil2 wrote:
>
> Hi Fred,
>
> Well my thoughts on this would be as follows:
>
> 1. Is there a problem in that area? Oil flow tests would show up any separations
in that area or maybe someone with a dirty aircraft has flown through rain
and has some pictures of the surface flow patterns that were left. If there
is no obvious problem then I'd leave it alone.
>
> 2. If there is a problem then making a really good job of the wing fillets would
be the best approach and maybe trying to maximise the radius of that fillet
(larger radius = better). The problem with a large radius is what happens
when you come to the trailing edge of the wing (or in the Europa's case, where
the wing ends and the flap starts). You need to lose that large radius and run
it out to nothing smoothly.
>
> 3. Sealing the wing against the fuselage would definitely be good. On gliders,
we use PVC tape but that only works if you have a small 'wing stub' moulded
into the fuselage that the wing butts up to. On a Europa I would say that some
high density foam on the inside of the wing root fillet would do the trick
and when the wings are fitted, the foam is compressed and thus forms a nice seal.
I.m not sure what gaps people have between the fuselage and the wing fillets
but try and keep them as small as possible.
>
> In terms of drag reduction I would have thought that there is little to do on
the Europa. It's already an excellent design and the use of composite materials
(and ability to build almost any shape) helps this. Compared to some homebuilts
on the market using the same engine, it has to be a very efficient machine.
Having said that, you notice the difference on a glider if the wing roots
are not taped and the controls are not sealed and so all these little bits of
attention to detail would add up and help reduce the drag that little bit further.
>
> Actually, that's an interesting point above. Out of all the homebuilts powered
with a 912S, there can't be many aircraft that are faster than a Europa. There
is the DynAero MCR1 (which I had an amazing flight in once) and that is very
fast but look at the size of it - it's tiny. Anyone have any other comparisons?
>
> Phil
>
>
>
>
>
>
> Visit - www.EuropaOwners.org
>
>
>
>
>
>
>
>
>
--
Graham Singleton
Tel: +441629820187
Mob: +447739582005
Message 12
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Subject: | Re: Votex Generators |
Fred
The stall on the Europa is critically affected by the position and size
of the LE radius, Don and his aerodynamicist friend David tweaked the
leading edge, it's quite a sharp radius and there is a minute bulge
underneath. Hard to spot it but it does have a marked effect if it isn't
accurate.
On a couple of Europas I was involved with (both Classics) I made
templates of the first 10 inches of section at about 8 stations and the
builders spent many hours sanding to these templates. The stalls on both
these aircraft are relatively benign, unlike that of G-KWIP. Both are
fast too. It is all too easy to sand off the bumps in the section which
are meant to be there.
I have tried to attach a dwg file of the section coordinates/
Graham
Fred Klein wrote:
>
>
> On Thursday, May 10, 2007, at 02:41 PM, Graham Singleton wrote:
>
>> VGs were applied to the wing and canard of a Long EZ, which has
>> laminar sections on both, to reduce stall speed, the VGs re energise
>> the laminar boundary layer and help to prevent separation after the
>> max thickness point of the section. Stall was reduced by 7 kts.
>> Graham
>
>
> So here's a question...
>
> Is it conceivable that adding VGs to the Europa could reduce the stall
> speed sufficiently to meet the LSA requirements?
>
Message 13
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Subject: | Re: Votex Generators |
Phil, Graham and all,
In attachment my solution for the wing root drag problem. While building I
fixed the fairing as well to the wing as to the fuselage and cut it vertical
with the wing root. Then I reinforced both to become entire part and
sufficient solid. I also prolonged the upper side at the fuselage to cover
the gap for the flap torque tube so that no spoiled fuel or water could
penetrate the fuselage. This solution gave me some advantages:
- the fuselage is certainly reinforced
- the rigging of the wing is easier because you see exactly were the root
has to meet
- sealing with tape is easy as I did before with my gliders.
Thank you Phil for your much apreciated intervention.
Karel Vranken.
----- Original Message -----
From: "Graham Singleton" <grahamsingleton@btinternet.com>
<fklein@orcasonline.com>
Sent: Friday, May 11, 2007 7:58 PM
Subject: Re: Europa-List: Votex Generators
> Phil
> the nioest wing root I've seen is Ted and Justin's, small radius at the
> LE, large at the TE. picture attached. imho this is the way to do it,
> the fillet needs to be flexible to allow wing bending without crushing
> the fuselage side, so no more than 3 plies of BID at the edge. There are
> several Europas with this style but only Ted's has the elegant change of
> radius moving aft.
> Easier to rig a wing done like this too, something to line up with as it
> goes in.
> Graham
Message 14
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Subject: | Re: Votex Generators |
Graham,
Sorry I was not clear in my email to you. My references to Ted's radii
were to his trailing edge fillet were to the fillet at the rear of the
flap as viewed in plan form, not in cross section...I would not be one
to mess with Don and David's leading edge!
Fred
On Friday, May 11, 2007, at 02:05 PM, Graham Singleton wrote:
> Fred
> The stall on the Europa is critically affected by the position and
> size of the LE radius, Don and his aerodynamicist friend David tweaked
> the leading edge, it's quite a sharp radius and there is a minute
> bulge underneath. Hard to spot it but it does have a marked effect if
> it isn't accurate.
> On a couple of Europas I was involved with (both Classics) I made
> templates of the first 10 inches of section at about 8 stations and
> the builders spent many hours sanding to these templates. The stalls
> on both these aircraft are relatively benign, unlike that of G-KWIP.
> Both are fast too. It is all too easy to sand off the bumps in the
> section which are meant to be there.
> I have tried to attach a dwg file of the section coordinates/
> Graham
> Fred Klein wrote:
>> On Thursday, May 10, 2007, at 02:41 PM, Graham Singleton wrote:
>>> VGs were applied to the wing and canard of a Long EZ, which has
>>> laminar sections on both, to reduce stall speed, the VGs re energise
>>> the laminar boundary layer and help to prevent separation after the
>>> max thickness point of the section. Stall was reduced by 7 kts.
>>> Graham
>> So here's a question...
>> Is it conceivable that adding VGs to the Europa could reduce the
>> stall speed sufficiently to meet the LSA requirements?
>
> --
> This message has been scanned for viruses and
> dangerous content by MailScanner, and is
> believed to be clean.
>
> <aerofoil47in.dwg>
Message 15
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Subject: | Airbrake horn cover |
Would appreciate input how to cover airbrake control horn under pilot
right thigh. Picture?
Thx.
Ron Parigoris
Message 16
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Subject: | Re: Votex Generators |
Neither would I! I was replying to your earlier email Fred, asking about
stall speeds & VGs
Graham
Fred Klein wrote:
>
> Graham,
>
> Sorry I was not clear in my email to you. My references to Ted's radii
> were to his trailing edge fillet were to the fillet at the rear of the
> flap as viewed in plan form, not in cross section...I would not be one
> to mess with Don and David's leading edge!
>
> Fred
>
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