Today's Message Index:
----------------------
1. 03:14 AM - Communication short term..... (ptag.dev@tiscali.co.uk)
2. 05:37 AM - Re: motorglider V-speeds and registration (h&jeuropa)
3. 08:06 AM - A rare message..... (Fergus Kyle)
4. 09:44 AM - Re: A rare message..... (Karl Heindl)
5. 09:46 AM - Jab cooling (TELEDYNMCS@aol.com)
6. 01:42 PM - Re: Jab cooling (Duncan & Ami McFadyean)
Message 1
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| Subject: | Communication short term..... |
Hi! All
I have a major computer failure probably due to being like a squirrel
with my filling !(according tomy son anyway !)
Any urgent messages will have to be by phone 07973 832741.
In the short term I can collect e-mails week day mornings from my
son's computer until my Tiscali account gets too full for the same
reason ! and until I get the beast sorted out ... need this problem as
much as a hole in the head at present. But at least my daily trips to
Lincoln Hospital can be now put to better use ! Those with continued
interest in my Torque tube clamp mod will either have to await my
resssurection or use the pne number above, please.
Regards
Bob Harrison G-PTAG
__________________________________________________
Tiscali Broadband only 7.99 a month for your first 3 months! http://www.tiscali.co.uk/products/broadband/
Message 2
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| Subject: | Re: motorglider V-speeds and registration |
Alan,
I have copies of the registration made. Please send me your email address off
list.
Jim Butcher
butcher43@att.net
do not archive
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=137805#137805
Message 3
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| Subject: | A rare message..... |
Hello,
We often see complaints regarding after-sales service of some of the
people who accept our money in exchange for their goods/services,
I'd like to counter that with good news.
Last Tuesday, 25SEP 07, as I was passing close to the front of the
engine, my sleeve caught one of the sintered brushes which are meant to
engage the rotating rings of my Woodcomp 3000-3 prop (not instralled). It
snapped the brush in half - just another trifling reverse, as I went to bed
shaking my head.
The next morning I emailed Jiri Holoubek near Prague with a sketch
and description of what had happened. By now it was 4pm his time. I received
an email reply about 1-1/2 hours later to say he would send a replacement.
It arrived this morning in the mail (two replacements) with the
date-stamp showing "27.09.07" as the posting. He must have arranged to post
it that afternoon.
You can't ask for more than that, especially on a small item that
couldn't have much profit to it. I thought you should know.
Cheers, ferg
Message 4
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| Subject: | A rare message..... |
Hi ferg,
That is amazing. I had the same happen to me and it took about 4 weeks to
get the replacement.
Karl
>From: "Fergus Kyle" <VE3LVO@rac.ca>
>To: "EUROPALIST" <europa-list@matronics.com>
>Subject: Europa-List: A rare message.....
>Date: Wed, 3 Oct 2007 11:00:54 -0400
>
>
>Hello,
> We often see complaints regarding after-sales service of some of the
>people who accept our money in exchange for their goods/services,
> I'd like to counter that with good news.
> Last Tuesday, 25SEP 07, as I was passing close to the front of the
>engine, my sleeve caught one of the sintered brushes which are meant to
>engage the rotating rings of my Woodcomp 3000-3 prop (not instralled). It
>snapped the brush in half - just another trifling reverse, as I went to bed
>shaking my head.
> The next morning I emailed Jiri Holoubek near Prague with a sketch
>and description of what had happened. By now it was 4pm his time. I
>received
>an email reply about 1-1/2 hours later to say he would send a replacement.
> It arrived this morning in the mail (two replacements) with the
>date-stamp showing "27.09.07" as the posting. He must have arranged to post
>it that afternoon.
> You can't ask for more than that, especially on a small item that
>couldn't have much profit to it. I thought you should know.
>Cheers, ferg
>
>
_________________________________________________________________
Can you see your house from the sky? Try Live Search Maps
http://maps.live.com
Message 5
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In a message dated 10/3/2007 3:00:41 AM Eastern Daylight Time,
europa-list@matronics.com writes:
I recall that in 1995 I asked the late Richard Cabrinha why he had changed
from a chin intake to a pair of Lo-Presti style circular intakes on his Free
Spirit Mark II, for cooling a Continental IO 360, and he replied "because
they work!" He told me that if the diameter were too large then there would
be a reverse flow, spilling air out round the circumference of each intake.
He refined the size by putting some oil around each rim and doing a quick
circuit: inspection on landing showed whether the oil film had spread
inwards or migrated outwards, and he would then the repeat the test with
different diameters accordingly.
Hi Mike, Graham, and all,
That is essentially what I've done with my string testing, although I wasn't
aware that size had much to do with it (Typical male, huh?) I've not played
with changing the size of the intake at all. It does seem like 25 square
inches of intake should be more than adequate for cooling this little engine,
though.
.
What I've seen in my string tests is an apparent low pressure area forming
on the outboard side of the left intake as viewed from the cockpit. I've also
noticed an apparent high pressure area directly in front of the inlet when my
turbulators are not installed and this high pressure "bubble" rejects the
string as it approaches the intake from upwind. At one point it turns the
string 180 degrees and it blows towards the fan. Installing turbulators at the
lip
of the intake helped considerably. I went from about 50% of the intake
"accepting" the string, to what I'd estimate as about 80% now accepting the
string in the intake. Still not perfect, but I'm still playing with it, too. What
I have seen in terms of engine cooling has been dramatic, though.
I need to dig up the Lo-Presti info and take a look at it. That's about the
fifth time somebody has mentioned that name to me.
An A&P friend of mine stopped by my shop yesterday and I showed him what I
was doing. He's also a glider pilot and amateur aerodynamicist. We also
discussed exit cooling flow. The trigear has a rather large triangle shaped
reinforcing piece on the nosegear leg just below and outside the line of the cowl.
This triangle is flat to the relative wind, probably worse at climb angles,
and I would reckon that it causes some disturbance right where the cooling air
from the cowl is trying to exit. Whether or not that is interfering with my
cooling flow remains to be determined, but it sure looks like it could use a
fairing to split the flow, hopefully accelerating it and causing a low
pressure area in that region. It stands to reason that cleaning up this area with
a
fairing might help create a bit of suction and aid cooling flow, too.
Graham said: I wonder if your turbulator is helping keep the flow attached
over the
whole of the outside of the cowl?
I'm thinking you are correct in your assessment there, Graham. I think
"re-exciting" the flow is indeed causing it to stay attached. FWIW, I've done
some
tuft testing on my wings and I seem to have laminar flow at least as far
back as the hinge line of the aileron. The wing tip is much cleaner than I
anticipated, too. There are very few modern sailplanes that get this level of
laminar flow that far back on the wing. Shaw and Dykins are obviously genius'.
I don't have enough knowledge on the subject to really know one way or the
other how internal duct pressure is related to flow, but my tests seem to
indicate that there is either no relationship, or the relationship is inverse.
If
you think about it, restricting the flow would cause higher pressure, just
as it does when you put your finger on the end of a running garden hose. The
pressure increases, but the flow decreases. That seems to be what is happening
here.
Regards,
John Lawton
Whitwell, TN (TN89)
N245E - Flying
Message 6
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John,
You could also try:
"An investigation of the aerodynamics and cooling of horizontally
opposed engine installation"
SJ Miley. SAE 1977.
Which contains velocity ratio investigations for a number of different
nostril shapes, including 'LoPresti' style.
Duncan Mcf.
----- Original Message -----
From: TELEDYNMCS@aol.com
To: europa-list@matronics.com
Sent: Wednesday, October 03, 2007 5:16 PM
Subject: Europa-List: Jab cooling
In a message dated 10/3/2007 3:00:41 AM Eastern Daylight Time,
europa-list@matronics.com writes:
I recall that in 1995 I asked the late Richard Cabrinha why he had
changed
from a chin intake to a pair of Lo-Presti style circular intakes on
his Free
Spirit Mark II, for cooling a Continental IO 360, and he replied
"because
they work!" He told me that if the diameter were too large then
there would
be a reverse flow, spilling air out round the circumference of each
intake.
He refined the size by putting some oil around each rim and doing a
quick
circuit: inspection on landing showed whether the oil film had
spread
inwards or migrated outwards, and he would then the repeat the test
with
different diameters accordingly.
Hi Mike, Graham, and all,
That is essentially what I've done with my string testing, although I
wasn't aware that size had much to do with it (Typical male, huh?) I've
not played with changing the size of the intake at all. It does seem
like 25 square inches of intake should be more than adequate for cooling
this little engine, though.
.
What I've seen in my string tests is an apparent low pressure area
forming on the outboard side of the left intake as viewed from the
cockpit. I've also noticed an apparent high pressure area directly in
front of the inlet when my turbulators are not installed and this high
pressure "bubble" rejects the string as it approaches the intake from
upwind. At one point it turns the string 180 degrees and it blows
towards the fan. Installing turbulators at the lip of the intake helped
considerably. I went from about 50% of the intake "accepting" the
string, to what I'd estimate as about 80% now accepting the string in
the intake. Still not perfect, but I'm still playing with it, too. What
I have seen in terms of engine cooling has been dramatic, though.
I need to dig up the Lo-Presti info and take a look at it. That's
about the fifth time somebody has mentioned that name to me.
An A&P friend of mine stopped by my shop yesterday and I showed him
what I was doing. He's also a glider pilot and amateur aerodynamicist.
We also discussed exit cooling flow. The trigear has a rather large
triangle shaped reinforcing piece on the nosegear leg just below and
outside the line of the cowl. This triangle is flat to the relative
wind, probably worse at climb angles, and I would reckon that it causes
some disturbance right where the cooling air from the cowl is trying to
exit. Whether or not that is interfering with my cooling flow remains to
be determined, but it sure looks like it could use a fairing to split
the flow, hopefully accelerating it and causing a low pressure area in
that region. It stands to reason that cleaning up this area with a
fairing might help create a bit of suction and aid cooling flow, too.
Graham said: I wonder if your turbulator is helping keep the flow
attached over the
whole of the outside of the cowl?
I'm thinking you are correct in your assessment there, Graham. I think
"re-exciting" the flow is indeed causing it to stay attached. FWIW, I've
done some tuft testing on my wings and I seem to have laminar flow at
least as far back as the hinge line of the aileron. The wing tip is much
cleaner than I anticipated, too. There are very few modern sailplanes
that get this level of laminar flow that far back on the wing. Shaw and
Dykins are obviously genius'.
I don't have enough knowledge on the subject to really know one way or
the other how internal duct pressure is related to flow, but my tests
seem to indicate that there is either no relationship, or the
relationship is inverse. If you think about it, restricting the flow
would cause higher pressure, just as it does when you put your finger on
the end of a running garden hose. The pressure increases, but the flow
decreases. That seems to be what is happening here.
Regards,
John Lawton
Whitwell, TN (TN89)
N245E - Flying
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