SCAT Electronic News 18 March issue 558

SCAT Electronic News 18 March issue 558


Table of Contents
=================
SCAT Annual Flash
Holiday on ice 2001 - Nereng
Science Olympiad or Brokenspar meets authority
Woebbeking Airfoil Bradley and Woebbeking
xfoil on the web - Baxter and Drela
In response to easyryder, "F1C participation" - Menanno
JATO like effects of gearing? - Skykeing
The future?? - Markos
Applogies - Editor

SCAT Annual Flash
=================

F1A Zink
F1B Booth
F1C Archer

A Great contest, perfect weather, tough thermal finding.

Full results real soon now.


Holiday on ice 2001
===================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.



Clear sky, 1-3 m/sec.wind, temp. -8 - 0 Celsius, 2 inc. water and 4 =
inc.snow on the ice, but now problem.
best regards
Vegar Nereng.

F1A
---
PlasEtternavn Fornavn NasjonOmg1 Omg2 Omg3 Omg4 Omg5 Sum FlyOfTotal
1 RUMPP STEFAN GER 210 180 180 180 180 930 275 1205
2 HOLMBOM MIKAEL SWE 210 180 180 180 180 930 266 1196
3 VALO JARI FIN 210 180 180 180 180 930 261 1191
4 FINDAHL PER SWE 210 180 180 180 180 930 254 1184
5 KOTCHKAREV MIKHAIL RUS 210 180 180 180 180 930 250 1180
6 JAVIER ABAD ESP 210 180 180 180 180 930 238 1168
7 VAN NEST BRIAN USA 210 180 180 180 180 930 229 1159
8 POLIEV VALEREI RUS 210 180 180 180 180 930 222 1152
9 FÄRBER MATHIAS GER 210 180 180 180 180 930 220 1150
10 PERSSON ANDERS SWE 210 180 180 180 180 930 218 1148
11 KULMAKKO KIMMO FIN 210 180 180 180 180 930 217 1147
12 MAKAROV SERGEI RUS 210 180 180 180 180 930 212 1142
13 STEFFENSEN INGOLF NOR 210 180 180 180 180 930 203 1133
14 DE BOER PIETER NED 210 180 180 180 180 930 199 1129
15 ARINGER GERHARD AUT 210 180 180 180 180 930 198 1128
16 RONKANEN PEKKA FIN 210 180 180 180 180 930 196 1126
17 LIHTAMO MATTI FIN 210 180 180 180 180 930 188 1118
18 LARSSON LARS SWE 210 180 180 180 180 930 16 946
19 LEINO LAURA FIN 205 180 180 180 180 925 925
20 HEIKKONEN TIMO FIN 200 180 180 180 180 920 920
20 VARHOS DENIZ SWE 209 171 180 180 180 920 920
20 NYHEGN BO DEN 200 180 180 180 180 920 920
23 YABLONOVSKY IGOR UKR 194 180 180 180 180 914 914
24 NERENG VEGAR NOR 191 180 180 180 180 911 911
25 SUNDSTEDT INGE SWE 188 180 180 180 180 908 908
26 ISOTALO TOMMI FIN 201 158 180 180 180 899 899
27 VAN ELDIK ANTON NED 205 180 180 146 180 891 891
28 AMLIE HÅVARD NOR 181 180 168 180 180 889 889
29 KLUNGREHAUG ATLE NOR 179 180 180 177 172 888 888
30 EDLUND ULF SWE 210 180 180 133 180 883 883
31 KUTVONEN ARI FIN 210 180 180 129 180 879 879
32 OLDFIELD DAVID GBR 179 180 178 180 149 866 866
33 TROGEN GÖRAN SWE 210 108 180 180 180 858 858
34 PAJUNEN TIMO FIN 126 180 180 180 180 846 846
35 NYHEGN HENNING DEN 179 121 174 180 180 834 834
36 WIVARDSSON SOFIA SWE 167 180 146 151 170 814 814
37 KUNINKAS JUHANI FIN 194 136 140 180 139 789 789
38 OLSTAD SVEIN NOR 142 141 153 180 146 762 762
39 KLUNGREHAUG(JR) GYRI NOR 76 173 153 150 152 704 704
40 KUEHN JENS GER 163 132 120 140 139 694 694
41 KLEMENTSEN ANDERS NOR 129 180 125 98 149 681 681
42 RUNNARI (JR) JUHO FIN 130 168 180 69 70 617 617
43 RUNNARI VALVE FIN 163 154 58 121 59 555 555

F1B
---
PlasEtternavn Fornavn NasjonOmg1 Omg2 Omg3 Omg4 Omg5 Sum FlyOfFlyOfTotal
1 MEUSBURGER HARALD AUT 210 180 180 180 180 930 420 316 1666
2 RUYTER PIM NED 210 180 180 180 180 930 420 306 1656
3 ROSONOKS VIKTOR LAT 210 180 180 180 180 930 417 1347
4 PEERS BRIAN RUSSELL GBR 210 180 180 180 180 930 386 1316
5 ANDRIUKOV ALEX USA 210 180 180 180 180 930 385 1315
6 EIMAR BROR SWE 210 180 180 180 180 930 361 1291
7 FORSMAN JANNE SWE 210 180 180 180 180 930 349 1279
8 WIVARSSON GUNNAR SWE 210 180 180 180 180 930 335 1265
9 BUKIN ALEXEI UKR 210 180 180 180 180 930 333 1263
10 BROBERG HÅKAN SWE 210 180 180 180 180 930 320 1250
10 GHIO WALT USA 210 180 180 180 180 930 320 1250
12 LINKOSALO TAPIO FIN 210 180 180 180 180 930 314 1244
12 SOLDOV MAXIM RUS 210 180 180 180 180 930 314 1244
14 SKJULSTAD PER TH NOR 210 180 180 180 180 930 313 1243
15 MACKUS ROLANDAS LIT 210 180 180 180 180 930 309 1239
16 WALTONEN YRJÖ FIN 210 180 180 180 180 930 303 1233
17 STEFANCHUCK STEPHAN UKR 210 180 180 180 180 930 290 1220
18 SALZER KLAUS W AUT 210 180 180 180 180 930 271 1201
19 LØSNESS ARNE NOR 210 180 180 180 180 930 265 1195
20 CHELEPOV ALEXANDER RUS 210 180 180 180 180 930 262 1192
21 WOOLNER MICHAEL GBR 210 180 180 180 180 930 260 1190
22 HOLLANDER NILS ERIK SWE 210 180 180 180 180 930 257 1187
23 KUTVONEN ARI FIN 210 180 180 180 180 930 244 1174
24 KIISKINEN MARKKU FIN 210 180 180 180 180 930 240 1170
25 WOODHOUSE MICHAEL GBR 210 180 180 180 180 930 239 1169
26 JÄCKEL MICHAEL GER 210 180 180 180 180 930 232 1162
27 ASLETT BERNHARD GBR 210 180 180 180 180 930 227 1157
28 SAARI PEKKA FIN 210 180 180 180 180 930 219 1149
29 ISOTALO JANNE FIN 210 180 180 180 180 930 134 1064
30 ISOTALO JUHANI FIN 210 180 180 180 170 920 920
31 BORTNE TOR NOR 210 180 180 180 169 919 919
32 WOLD JAN NOR 194 180 180 180 180 914 914
33 HOFFMANN MANFRED GER 169 180 180 180 180 889 889
34 PRATT JOHN USA 210 146 144 180 180 860 860
35 SETTEM STEINAR NOR 131 180 167 180 180 838 838
36 KILPELÄINEN OSSI FIN 178 119 180 180 180 837 837
37 ROHRKE RICH USA 210 151 0 361 361
38 HORAK LADI CAN 0 180 180 180
39 TORHUS (JR) KRISTIAN NOR 16 16 16

iF1C
---
PlassEtternavn Fornavn Nasjon Omg1 Omg2 Omg3 Omg4 Omg5 Sum
1 LINDNER ANDREAS GER 240 180 180 180 180 960
2 ARINGER GERHARD AUT 235 180 180 180 180 955
3 KUUKKA KAARLE FIN 240 180 180 112 180 892
4 ROOTS JÜRI EST 157 115 180 180 180 812
5 ÅGREN GUNNAR SWE 159 180 160 177 125 801
6 GRETTER CLAUS GER 195 67 180 180 158 780
7 LINDGREN KARI FIN 193 58 180 180 155 766
8 NIIRANEN TIMO FIN 203 180 84 102 33 602



Science Olympiad or Brokenspar meets authority:
================================================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.




As a mentor ( as it's called ) for a grandson and his partner O'Connor,
after two weeks of building and rebuilding this ungainley airplane,
we arrive at the flying site ( early ) for testing and were told by the
teacher in charge - You have to launch from that basketball foul
line,
see those two chairs - . It didn't get any better.

However, first place and on to State level !



Woebbeking Airfoil
==================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.


Roger,

Recently I exchanged E-mails with Gerhard Woebbeking concerning his stab
airfoil. Whit Gerhard approval I am sending you the questions I ask him and
his reply.

Jim Bradley


Gerhard,

Maybe you can answer a question for me. Is there more than one version of
your stab airfoil or has it just been scaled to different % of thickness by
different people? I have also seen some versions that show the top camber
curved instead of being a straight line from the high point to the trailing
edge. Any information you can share with me would be greatly appreciated. I
am using your airfoil on my latest F1A and have been very happy with the way
the model flies.

Jim Bradley


Jim,
it's true that there are different versions of my tail profile used
by different pilots. The answer gives the theory; it is very difficult
to appraise small modifications in practices

1) Airfoil is not influenced by the Cheesman of 1952 which is a
kind of symmetrical profile with a flat bottom to ease the
construction. This profile has
a chamber in the back part of the upper surface of course.

2) After discussing the matter with Reiner Hofsaess I mixed up a typical wing
profile of a small Hand Launch Gliders with a round nose like the Clark Y 12%
or the Goe 625.

3) Why this? I wanted little sensitivity in a period of small changes of the
airflow and good reaction to big changes (turbulence, thermals, stall) like
thick round airfoils offer.

4) In the best wind tunnel test ever made (Schmitz, Aerodynamik des
Flugmodells) you can read, that the 15% Goe 625 at + 8 to 10 degrees
generates the same positive lift as - 8 to 10 degrees negative lift
(Re 20.000). So why not get rid of the thick hump (upper surface)
with all the drag and turn downside up?

5) Result was only 8% thick but able to generate high lift at high angles of
attack (see 3) with a small increase of lift at low angles both due to
the thick round nose. Andres Lepp could not find any difference between
7% and 8%. Alexander Andruikov moved the high point more and more forward
(exactly like the bottom of the
Goe 625). Stamov introduced a turbulator to gain more pull while towing.

That's the story.

Regards,
Gerd

Gerhard Woebbeking
Holstenstrasse 108
22767 Hamburg/ Germany
Tel.+49-40-3898310 This email address is being protected from spambots. You need JavaScript enabled to view it.




xfoil on the web
================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.

Dr. Mark Drela's airfoil analysis/synthsis program Xfoil is now free on the
web.

Now alleged to produce "reasonable" low Reynolds number results.



Xfoil web site

http://raphael.mit.edu/xfoil/

Xfoil user group

http://groups.yahoo.com/group/xfoil


In response to easyryder, "F1C participation"
=============================================

Friday, March 16, 2001

If were all looking for "wonderful growth" then lets all start have more
babes! But if you want to have true growth in F1c than don't hinder the
great minds that have given and innovated so much to our sport of flying.
F1C flyers compete because it's hard not because it's easy. This argument
over high tech or gears verses elimination or handicapping is nothing more
than the struggles of a democratic government vs a dictorship,
If you don't know the difference, then just think about what country
or political system you would like to live in ...

As for the cost of an air plane these days, I suggest folks that can't
afford to fly modern models, revert back to flying hand launch gliders! No
disrespect to hand launch. The whole idea that we should lower the bar to get
more enthusiasm In F1C is Insane! The allure of F1C is that it is so
illusive. Last thoughts The competition in AMA flying is Myself and when I
break into F1C I will still be competing against myself, To dream to build
to succeed to win!
Frank Menanno

[This article has been edited slightly, appologies to Frank but it
does express his original sentiments.]


JATO like effects of gearing?
=============================
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.

Concerning various observations/speculations on how much
higher the geared ships are getting A question is just how
much higher can we expect, theoretically, for a geared FAI
to actually get?

I realize I know just enough to get into to trouble trying
to play engineer but it seems that the projected altitude
gain from gearing doesn't match up with subjective
observations. Roughly, IF propellor efficiency of gearing is
80% and a fixed propellors say, 60% then there is a 20%
advantage going to the gears. But 20% efficiency does NOT
translate automatically to a 20% gain in altitude. The gain
in altitude would be on the order of a third. So if altitude
gained is say 450,' then 106.66% would be 480' thus giving
an advantage to the geared airplane of 30'.

Now that is a welcome improvement, granted, but doesn't
seem an overwhelming one considering the entire selection
menu involved in flying.

If I've misunderstood elements of Fred Wieke's (sp) classic
book on propellor theory and design then would qualified
people please step up and set this straight for everyone's
benefit.

Skyscraper



The future??
============
Author : This email address is being protected from spambots. You need JavaScript enabled to view it.

Could it be that the demise of FAI is the logical outcome of the trend in
rules changes, both instituted and proposed? If one plots the engine run
time in F1C from 10 sec to 7 to 5, and now proposed to 4-point something or
other over the years, the inescapable conclusion is that the apporach to
zero is accelerating...hence no more F1C. For F1B, the slope of the curve
for motor weight is more gradual, but the intercept with the abscissa seems
also bound to happen. No motor = no F1B. That leaves us with F1A which has
been stable since the towline was reduced fromm 100 meters to 50, but since
we are all getting older and unable to run, won't be worth changing anyway.
Just kidding...or am I ?
Chuck


Applogies
=========

In that last issue we credited Gil Morris's article to Buxton.
In addition there was a piece written by one JimmyB aka
easyryder - who was not Buxton either.

In our hurry to get to Lost Hills for the SCAT Annual - a
BlueBird day ! the editorial dept got it's wires crossed.

........
Roger Morrell