radiators have no influence on speed

BP_Tailspin · #1 10-31-2011, 04:54 PM

This place never ceases to entertain me …

Quote:

Originally Posted by David198502

i surprisingly just found out that the rads settings of the 109 have no impact on speed at all...

Should they have an impact on speed?

Quote:

Originally Posted by David198502

normally i fly with them as much closed as possible, to avoid engine overheating, while maintaining the minimum air resistance...however i found out that one can leave the rads fully open and still reach and hold the top speed in level flight....

Keeping your 109 cool sounds good to me and without a performance hit is even better.

Quote:

Originally Posted by David198502

that should be looked into by the devs,

I think there busy trying to make the “game” playable.

Quote:

Originally Posted by David198502

cause i would assume that a fully opened radiator should cause enough surface to slow the aircraft down...

Key word here is “assume”

Quote:

Originally Posted by David198502

i have to say that this fact is extremely disappointing,

Fact? Please quote your aeronautical engineering data.

Quote:

Originally Posted by David198502

as CEM and FMs are supposed to be the strengths of this game(sim?)

Key word here is “game” but maybe it’s more of a “sim” than we think. The P51 Mustang’s radiator has a low/no drag design.

“The duct for the radiator was designed to slow the incoming air down. The air could then absorb more heat from the radiator, but the radiator needed to be made larger because of the slower air velocity, which meant installation in the rear fuselage. After the air passed through the radiator, it expanded due to the heat and was accelerated out the back, producing some thrust to counter the drag the radiator caused.”

I don't have the time or energy to do the research the 109’s cooling but here’s some cool (pun intended) data about the pesky little 109 I did find. Instead of beating up the devs … research it and present the data to the devs.

http://www.wwiiaircraftperformance.o...09g-14026.html

Flanker35M · #2 10-31-2011, 05:06 PM

S!

Addman, try to find the book called Lentäjän Näkökulma II (Pilot's Point of View II freely translated). Written by Jukka Raunio. ISBN 951-96866-0-6

ACE-OF-ACES · #3 10-31-2011, 05:12 PM

Since David was unable, or unwilling to provide the real 'data' his claim is based on, I figured I would give it a quick look.

To see what all the fuss is about, ie are we talking about

10?
20?
30?
40?

In doing so I found some 109G data but not E data, here is the sorce

http://www.wwiiaircraftperformance.o...9/14026pg9.jpg

Now it is really hard to read the speed axis, but it 'looks' like it goes

520
530
540
550
560

If that is the case, than the 'difference' in speed between open and closed is..

5 kph

Which is well within the pilot error noise

Thus, IMHO, the only way to detect this small change is to log the data and account for the pilot errors

PS correct me if I am wrong, but the rads on the 109 changed alot from the E to the G, so, assuming Jerry did a better job on the new rads, we can only assume that the older E rads caused more drag, and thus impacted speed more. But, even if the change was doulbe this, say 10kph, it is still well within the pilot error noise

David198502 · #4 10-31-2011, 05:20 PM

Quote:

Originally Posted by ACE-OF-ACES

Since David was unable, or unwilling to provide the real 'data' his claim is based on, I figured I would give it a quick look.

To see what all the fuss is about, ie are we talking about

10?
20?
30?
40?

In doing so I found some 109G data but not E data, here is the sorce

http://www.wwiiaircraftperformance.o...9/14026pg9.jpg

Now it is really hard to read the speed axis, but it 'looks' like it goes

520
530
540
550
560

If that is the case, than the 'difference' in speed between open and closed is..

5 kph

Which is well within the pilot error noise

Thus, IMHO, the only way to detect this small change is to log the data and account for the pilot errors

PS correct me if I am wrong, but the rads on the 109 changed alot from the E to the G, so, assuming Jerry did a better job on the new rads, we can only assume that the older E rads caused more drag, and thus impacted speed more. But, even if the change was doulbe this, say 10kph, it is still well within the pilot error noise

well that document is really hard to read....however how do you come to the conclusion of 5kph differnce?

maybe i read it wrong....there are two different graphs which show the speed per rads setting.
however both show a straight decreasing line with the same angle...so the difference remains the same.
the lower line shows a speed of 555kph with 50mm opened rads, and only 505kph with 310mm opened rads(which is not fully open).

50kph difference between not fully closed and not fully opened rads...

ACE-OF-ACES · #5 10-31-2011, 05:43 PM

Quote:

Originally Posted by David198502

well that document is really hard to read....however how do you come to the conclusion of 5kph differnce?

maybe i read it wrong....there are two different graphs which show the speed per rads setting.
however both show a straight decreasing line with the same angle...so the difference remains the same.
the lower line shows a speed of 555kph with 50mm opened rads, and only 505kph with 310mm opened rads(which is not fully open).

50kph difference between not fully closed and not fully opened rads...

As noted, hard to read the graph, but assuming 'speed' is on the bottom (x axis) and that it goes as follows

520 - 530 - 540 - 550 - 560

Now looking at the point where the two curves intersect (y=0) the bottom (x axis) we have

1st @ ~523.5kph
2nd @ ~528.5kph

5 = 528.5 - 523.5

That is what I got, but again, I could be reading it wrong too.. That graph is hard to read

But..

Lets not use that graph.. Lets use the 109E data your claim was based on! That would be the correct thing to do! Now that I got your att on the subject!

David198502 · #6 10-31-2011, 05:55 PM

Quote:

Originally Posted by ACE-OF-ACES

As noted, hard to read the graph, but assuming 'speed' is on the bottom (x axis) and that it goes as follows

520 - 530 - 540 - 550 - 560

Now looking at the point where the two curves intersect (y=0) the bottom (x axis) we have

1st @ ~523.5kph
2nd @ ~528.5kph

5 = 528.5 - 523.5

That is what I got, but again, I could be reading it wrong too.. That graph is hard to read

But..

Lets not use that graph.. Lets use the 109E data your claim was based on! That would be the correct thing to do! Now that I got your att on the subject!

the whole document is twisted 90° left.
so the speed is actually on the y axis.but there is also the temperature on the y axis as well in the lower half...
and the rads settings are on the x axis in mm.

so the doc you provided states a difference of more than 50kph between open and closed rads.

ACE-OF-ACES · #7 10-31-2011, 06:15 PM

Quote:

Originally Posted by David198502

the whole document is twisted 90° left.
so the speed is actually on the y axis.

Disagree.. Look at the top of the document.. The heading is not rotated, which is the way it is scanned in and how it will appear when you click on the link. Thus all my references are to how it is presented. PS the word is rotated not twisted

Quote:

Originally Posted by David198502

but there is also the temperature on the y axis as well in the lower half...

Which pertains to the temperate graph.. which is not what we are talking about, we are talking about how it affected the speed

Quote:

Originally Posted by David198502

and the rads settings are on the x axis in mm.

If you want to rotate the graph, go for it, but all my references are to the graph in how it is presented (un rotated) in a typical 8 1/2 by 11 sheet of paper

Quote:

Originally Posted by David198502

so the doc you provided states a difference of more than 50kph between open and closed rads.

Nope..

Not based on the numbers I read, i.e.

(left) 520 - 530 - 540 - 550 - 560 (right)

addman · #8 10-31-2011, 05:13 PM

Quote:

Originally Posted by Flanker35M

S!

Addman, try to find the book called Lentäjän Näkökulma II (Pilot's Point of View II freely translated). Written by Jukka Raunio. ISBN 951-96866-0-6

Thanks! Found it at the city library, time to practice on that Finnish of mine.