SEN-488 October 18 2000/attachments

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News and Reports 2000 - second half
SCAT Electronic News 18 October 2000 issue 488 - Attachments

Attachment supplement
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King
King
Instructions for anodising from Bob Beecroft via Al Ulm

P. King   (Climb Simulation..again)

Dear Jean,

First of all, I misunderstood you regarding the flight speed of differing 
AR's.  Of course the higher the AR the lower the CL therefore the higher the 
velocity.  

I have checked up on how I handle the effect of Re No in the climb mode and 
this is the situation with some results and graphs, attached in Exel.

In fact the Re is simulated during the climb and gave the following results 
when I ran two cases.  ie.  AA's AA30 (AR ca 15.8 and Alex's 'Long model'  AR 
ca 22 plus.

If you can download the Exel spread sheet, you will see figures for velocity, 
climb angle and CL.   They show what one would expect but notice that the 
motor run stays about the same at ca 43.5 secs in both cases.

A short summary of the comparitive performance is as follows:

            LOW AR              HIGH AR
Motor run      43.65                       43.55
Glide CL       1.017                         0.982
Height (m)     104.75                  106.95
Duration         369 sec                    397 sec

Notice the duration is slightly less for the high AR despite the higher climb 
!! (Due to Re effect on the glide at high AR.

A look at the spread sheet will show that, as we would expect, the CL is 
slightly higher for the Low AR and the Velocity is slightly lower.   An 
interesting thing I found was that the difference is far more marked at the 
end of the climb when the CL is highest.    During the 1st 2/3rds of the 
climb there is little difference in either speed or CL.   To sum up, the High 
AR Wake climbs just over two meters higher but takes an almost identical time 
to get there !!!  How does all this compare with your observations and 
calculations.   As I understand it,  the effect is similar to what you have 
noticed but the magnitude of difference is lower ??    It is very welcome to 
have all this feed back and it all helps enormously in refining the computer 
simulations.  All the best to you Jean !!

Peter King





NEW EXEL GRAPHS for Climb Sim.

I have now done a better spread sheet, (See attachment), of the effects of AR 
on the F1B climb.
It now shows 3 AR's ranging from 13/1 to 22/1.  In fact the duration is 
highest at 22/1

Peter King


.....
Roger Morrell

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