Official Fulqrum Publishing forum - Why still no dive acceleration difference?

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- - Why still no dive acceleration difference? (http://forum.fulqrumpublishing.com/showthread.php?t=31464)

Quote:

Originally Posted by FC99 (Post 416047)

Planes don't fly in vacuum. Your diving physics is missing drag.

I just put everything simply in to the "backforce"

even the air fricition and what so ever are supposed to be within the "back force"

and

if the missing drag u mentioned is the drag force by the engine

JTD have already said Mass*G >> engine thrust or so

"earth gravitational constant >> excess thrust / mass, so excess thrust / mass doesn't really matter."

he is wrong?

Quote:

Originally Posted by mayshine (Post 416052)

prove that,

I just put everything simply in to the "backforce"

even the air fricition and what so ever are supposed to be within the "back force"

and

if the missing drag u mentioned is the drag force by the engine

JTD have already said Mass*G >> engine thrust or so

"earth gravitational constant >> excess thrust / mass, so excess thrust / mass doesn't really matter."

please proof I flew in vacuum

I edited my previous post I wrote first version before you posted the calculation with "backforce". As you can calculate than do the full calculation and show us the results which proves how the game is wrong.

Just out of curiosity, how much difference you expect in dives?

Quote:

Originally Posted by FC99 (Post 416047)

So in this extreme case plane have 2,5m/s advantage in acceleration. What will be the difference in distance after 12-13 seconds?

And in the end try with different values for drag for each plane like it is in most real life cases.

come on!!!

in this extreme case it is not 2,5m/s advantage

its 50 % speed acceleration advantage

se FW = a1, La = a2
by the time la dive to from 300 to 500km/h , FW will get the speed of 600km/h

enought to do a verticle hammer action.

u know I can feel a lot of people are just defending theirself instead of
looking for truth

Quote:

Originally Posted by FC99 (Post 416060)

sorry I am not sure, but certainly will be different for current version

please do not be offenced,

you know I just try to........

acutually i am happy to be wrong

However I will try to provide more figures in the coming days

so late here now

Quote:

Originally Posted by FC99 (Post 416047)

yep, and it is only valid for 90 degree dive. You will have to multiply gravity force (mxg) with sine of the dive angle (assuming zero degrees of AoA) in a very simplified case. In the end, the final effect is marginal as tests show and as it is correctly modeled in Il-2 that has the basic physics 100% right.

Quote:

Originally Posted by mayshine (Post 416062)

I should be more precise and use m/s^2, I meant acceleration in my post and I still call it just 2,5m/s^2.

Even with this numbers distance between the planes will be less than 200m. Now plug in real numbers for FW and La and do the calculation again. When you include real numbers for mass, drag and thrust difference between La and FW will be very small.

LOL! You are so funny Mayshine. You tell us we aren't listening, and we don't know what we're talking about, but you have not listened to a bloody word anyone has said here, then you have the unmitigated gall to say that you would be happy to be proven wrong. That's Bull.

You are engaging in mental masturbation, pure and simple.

Have fun.

Quote:

Originally Posted by FC99 (Post 415966)

TAIC is very serious, have you read what I wrote about it? Report that deal with A6M5 and P-38,P-51 and P-47 is TAIC report No 38. A6M5 was tested against some Navy planes too,F6F-5, F4U-1D and FM-2. Results are published as TAIC Report No 17.

So far you didn't provided any evidence that would suggest that there is something fundamentally wrong with the game. IIRC Your picture that shows dives is from the post war magazine article.

And you will be hard pressed to find any RL test with planes diving at 90 deg straight into the ground or any 90 deg diving test for that matter, ~45 deg maximum angle during the dive is more typical.

1)FC99, 30 degree dive is very different from 60 degree dive,leave alone 90 vertival.

http://www.wwiiaircraftperformance.o...e52-taic38.pdf

P51D and zeke，@10000ft，begin dive at 200MPH（IAS），after 27s， reach 325IAS ，P51D is 200 yards ahead of zeke。

This test is probably a shallow dive(30 degree), in my opinion, if dive in 45-60 degree, P51D will get much more advantage. So we need more data on 45 degree dive.

2)

http://www.wwiiaircraftperformance.org/sl-wade.html

Quote:

Efficient streamlining and maximum speed both influence the dive, although a jet propelled aircraft will invariably have the advantage, particularly at the higher speeds, when the conventional fighter is progressively more handicapped by airscrew drag, and the accessory protuberances common to all conventionally powered fighters.

As speed building up, the drag force of airscrew increases sharply because the tip of airscrew is approvching sonic.

Does il2 model this increasing drag of propeller? Does il2 model enginee exhaust gas boost at high speed?

3) http://www.spitfireperformance.com/spit9v109g.html

Quote:

... I had the throttle open and I rolled over and headed on a course to cut the angle toward the 109s, which had separated a little. I wound on nose-heavy trim so essential to keep the aircraft in a high-speed dive. The Spit responded eagerly as I dove more steeply than the 109s, with Red Two and Three no doubt following, although I could not see them. The controls got very heavy as the airspeed needle moved far right at 480 mph. (Corrected for altitude, true airspeed approached 600 mph.) I could see that I was gaining on the nearest Me 109. That was something new. We were already half-way to Sicily; that was no problem. We knew from years of experience, dating back to the boys who had been in the Battle of Britain, that the 109 with its slim thirty-two foot wing was initially faster in a dive than we were. But we accepted that compromise happily in exchange for our broad superior-lift wing with its better climb and turn. One couldn't have it both ways. In any case, I was closing on this Me 109, which I recognised as a G. Perhaps he wasn't using full throttle.

We were down to 5,000 feet and our dive had become quite shallow. I could see the Sicilian coast a few miles ahead. Now I was within range at 300 yards, and I let him have a good squirt. The first strikes were on the port radiator from which white smoke poured, indicating a glycol coolant leak. I knew I had him before the engine broke out in heavy black smoke. (Bf 109 G-4 "Black 14" of 2(H)/14, flown by Leutnant Friedrich Zander, shot down 10 June 1943)

In il2, Does bf109 outdive spitfire at initial stage of dive?

Quote:

Originally Posted by BlackBerry (Post 416216)

This test is probably a shallow dive(30 degree), in my opinion, if dive in 45-60 degree, P51D will get much more advantage.

Accelerating from 200 to 325 the difference will be mostly the same, if diving for 27 s the difference will be bigger. However, in a steeper dive the limiting speed of 325 IAS will be reached sooner, therefore you'll be diving for less than 27 s, and separation will be smaller.

Quote:

Originally Posted by JtD (Post 416224)

http://www.wwiiaircraftperformance.o...e52-taic38.pdf

page 3-4

There is a "zoom"(should be nearly 90 degree upwards) test about P51D and Zeke with same cruising speed and altitude, side by side.

If il2-4.11m perfectly reproduce this "zoom" record, this thread's "boom" discuss can be closed.