Hey Kev367

[Flyboy]

you claimed the tiffi is slower then the pony on the deck, which sounded wierd to me, so i ran a few tests.

here are some figures to play around with.


in AH on the deck, fuel burn set to 0.0000000 (no burn at all)
the bolded number indicates WEP

typhoon at 25% fuel: 372 / 357
P51d at 25% fuel: 368 / 355

typhoon at 100% fuel: 371  / 356
P51d at 100% fuel: 366  / 354

the thing that stand out the most is the fuel load barely make any difference in speed.

anyone care to explain why? or is it a bug?

[Flyboy]

after a long search i finally found something that looks like an authentic performence test.

but be warned you wont like it
 http://home.epix.net/~cap14/typhoon.html

deck speed in AH (at 3700RPM +7 boost at 25% fuel) : 357MPH

speed at 1000feet from the source (3700RPM +7boost): 345.5MPH


overall top speed of the tiffi is reached at 20,200feet and its 394.5MPH

AH speed at 20,200feet : 400MPH



so the tiffi is hardly porked, more like over moddeled.

[Schatzi]

Originally posted by Flyboy

the thing that stand out the most is the fuel load barely make any difference in speed.

anyone care to explain why? or is it a bug?

As far as my (admittedly small) understanding of physics goes:



Level top speed has little to do with mass, just with drag. But it should take considerably longer time to reach that top speed (slower acceleration rate with higher mass).

[straffo]

Originally posted by Flyboy

so the tiffi is hardly porked, more like over moddeled.

...The tests were made between June and September, 1942.

hmmm ?

[Flyboy]

The Typhoon began to enter service with Nos 56 and 609 squadrons at Duxford in September of 1941.

From here


so whats your point straffo?

[culero]

Originally posted by Flyboy
From here


so whats your point straffo?

He's French. (It's his head.)

culero ~runslikehell~

[dtango]

the thing that stand out the most is the fuel load barely make any difference in speed.

Although increased weight incrementally increases the amount of induced drag..

(1) at high speeds near max level speeds parasite drag dominates and is the main determinant of max speeds attainable.

(2) induced drag reduces with increasing velocity because it takes less and less aoa to produce the lift needed to satisfy the L=W equation for level flight.

In short at high speeds associated with max level speed regions any incremental increase in induced drag is pretty insignificant and doesn't affect the max level speed.

However if you go to the other end of the envelope for the 1g stall speed of the aircraft you'll find that the increased weight makes a big difference in the 1g stall speed of the aircraft.

I think Nashwan is answering your other questions regarding the Typhoon figures you're asking about in the other thread in the Aircraft and Vehicles forum.

Tango, XO
412th FS Braunco Mustangs

[straffo]

Originally posted by Flyboy
From here


so whats your point straffo?

This is the test of a very very very early Typhoon.

It's like using the performances of the 109F to preted the 109G6 is overmodelled

[Blixen]

the data u have is earlie typh with 3 prop blades

[Kev367th]

Originally posted by Blixen
the data u have is earlie typh with 3 prop blades

Yup and we are supposed to have the later model.

Comparing a Tiffy with 25% fuel to a Pony with 25% is silly, prob closer to 50% Tiffy, 25% Pony. Getting the weights roughly equal is the problem.

To further confuse things, I seen figures that said its best alt was at 18.0k @405mph. Yet another claims 18.5k @ 412mph.

[TexMurphy]

Originally posted by Kev367th
Yup and we are supposed to have the later model.

Comparing a Tiffy with 25% fuel to a Pony with 25% is silly, prob closer to 50% Tiffy, 25% Pony. Getting the weights roughly equal is the problem.

To further confuse things, I seen figures that said its best alt was at 18.0k @405mph. Yet another claims 18.5k @ 412mph.

Doesnt matter with mass.

Mass matters for accelleration not max speed.

What will be different is how long it takes to reach top speed.

So if a tiffy at 25% fuel dives on something down low it will decelerate faster then a tiffy at 100% fuel. Simply because it has more momentum. So the heavier tiffy will be flying over max speed for a longer ammount of time.

If its in level flight then the 25% loaded tiffy will reach top speed faster then the 100% loaded one.

But that is all comparing accellerations not speed.

In fact Im not 100% sure there should be any speed difference at all. I need to read up on my physics here. Or HiTech could answer it.

Added mass forces the plane to create extra lift inorder to fly and this could create extra drag. But Im not sure if this is the case.

For example if you take two object same shape different mass (one 100 times heavier) and drop em from a plane they will reach the same speed. The heavier will reach the ground faster but that is just due to the faster accelleration time.

Tex

[WMLute]

Originally posted by TexMurphy
Doesnt matter with mass.

Mass matters for accelleration not max speed.

For example if you take two object same shape different mass (one 100 times heavier) and drop em from a plane they will reach the same speed. The heavier will reach the ground faster but that is just due to the faster accelleration time.

Tex

Ya' need to read up on terminal velocity.

[Flyboy]

anyone have data for the version we have in AH?

the web is full of contradicting data, thats why when i finally founded something that looked authentic, i posted it

guess ill start searching again...


P.S
tex, where the hell are you?

[Flyboy]

Originally posted by Kev367th
Yup and we are supposed to have the later model.

Comparing a Tiffy with 25% fuel to a Pony with 25% is silly, prob closer to 50% Tiffy, 25% Pony. Getting the weights roughly equal is the problem.

To further confuse things, I seen figures that said its best alt was at 18.0k @405mph. Yet another claims 18.5k @ 412mph.

a 100% tiffi is still faster then a 25% pony.

[TexMurphy]

Originally posted by Flyboy
P.S
tex, where the hell are you?

been at the GFs place alot lately.