Why still no dive acceleration difference?

[K_Freddie]

Thrust and drag are inside reasonable margins under level flights and climbs so there is no reason to believe that they are wrong during dive, especially during the initial phase.

Interesting.... and you actually believe this statement to be the 'absolute truth'

It is time to rethink FM policy...

[AndyJWest]

It is time to rethink FM policy...

Based on guesswork, or data?

[JtD]

Originally Posted by K_Freddie

We all know that the p47 'dropped like a brick'...

Actually, it's not "we all know", but "some think". I know that it dropped faster than a brick, and it does in game. A brick neither produces the thrust a P-47 produces, nor is it anywhere near as aerodynamic. However, this applies to about all WW2 fighter aircraft.

Anyway, you are more than welcome to do the research, dig up a few tests and take it from there.

[BlackBerry]

Originally Posted by FC99

Acceleration rate in dive is product of thrust, gravity and drag. Same equations are used no matter the plane attitude. Gravity is the same in the game no matter what the plane is doing. Thrust and drag are inside reasonable margins under level flights and climbs so there is no reason to believe that they are wrong during dive, especially during the initial phase.



We could but we prefer to have FM as realistic as possible.

especially during the initial phase.............

I have a question, does bf109g6as outdive spitfire IX or fw190A8 during the initial phase in 4.11m?

[BlackBerry]

Bf-109-G2
[Mass] kg
Empty 2320.0
TakeOff 2830.0

[Squares] m^2
Wing 16.16
Aileron 1.02
Flap 2.00
Stabilizer 1.90
Elevator 1.20
Keel 0.70
Rudder 1.10

[Polares]
lineCyCoeff 0.094
Cy0_0 0.15.............................................. .
AOACritH_0 21.0............................................
AOACritL_0 -16.0...........................................
CyCritH_0 1.48.............................................. .
CyCritL_0 -1.0230048.....................................
CxMin_0 0.027............................................. ..
parabCxCoeff_0 6.7E-4....................................

Spitfire.LF.IXC
[Mass]
Empty 2650.0
TakeOff 3300.0

[Squares]
Wing 19.0
Aileron 1.32
Flap 2.125
Stabilizer 1.90
Elevator 1.20
Keel 0.85
Rudder 1.10

[Polares]
lineCyCoeff 0.092
AOAMinCx_Shift 0.0
Cy0_0 0.1
AOACritH_0 16.0
AOACritL_0 -17.0
CyCritH_0 1.4
CyCritL_0 -0.7
CxMin_0 0.0232
parabCxCoeff_0 5.4E-4


P-47D-27
[Mass]
Empty 4630.0
TakeOff 6583.0

[Squares]
Wing 25.87
Aileron 1.45
Flap 2.76
Stabilizer 3.50
Elevator 2.05
Keel 1.30
Rudder 1.10

[Polares]
lineCyCoeff 0.092
AOAMinCx_Shift 0.9
Cy0_0 0.17
AOACritH_0 16.0
AOACritL_0 -15.0
CyCritH_0 1.25
CyCritL_0 -0.8
CxMin_0 0.0256
parabCxCoeff_0 4.8E-4


Bf-109G-2 = 0.027 * 16.16 = 0.43632
Spitfire.LF.IXC = 0.0232 * 19.0 = 0.4408
P-47D-27 = 0.0256 * 25.87 = 0.662272


Bf-109G-2
0.43632/2830 = 1.5417667844522968197879858657244e-4

Spitfire.LF.IXC
0.4408/3300 = 1.3357575757575757575757575757576e-4

P-47D-27
0.662272/6583 = 1.0060337232264924806319307306699e-4

[Crumpp]

JtD says:

Because in game, g applies the same to all aircraft. Just like in real life.

Tell me you don't touch any of the flight models.....

Excess thrust......not the same!

[FC99]

Originally Posted by K_Freddie

The final test would be P47-vs-something else.

We all know that the p47 'dropped like a brick'... if this doesn't happen in comparison to other a/c... we quiet simply have a FM problem .. period!


This is a valid, if not 'niche' point brought up by mayshine.. whether anybody likes it or not, is irrelevant.
and..
Yes Yes.. we've done the aeronautics and formulae ad-nauseum

Mayshine's question has been answered, dive acceleration difference exist in game already.

And P-47 falls like the brick in comparison with most other aircrafts.

Originally Posted by BlackBerry

I have a question, does bf109g6as outdive spitfire IX or fw190A8 during the initial phase in 4.11m?

Depending on initial conditions and your definition of "initial phase" that's probably possible.

FM data you posted for several planes looks like 4.11 data.

Originally Posted by Crumpp

Tell me you don't touch any of the flight models.....

Excess thrust......not the same!

And JtD is wrong in what exactly? AFAIK F=mg, g is a constant and is the same for every object in game.

[Crumpp]

And JtD is wrong in what exactly? AFAIK F=mg, g is a constant and is the same for every object in game.

Of course it is Fatcat. This is not the issue and completely irrelevant as to why your FM's would not exhibit any differences in dive acceleration. It does not answer the original poster's question.

Take the force triangle for a dive. A component of weight contributes to thrust based on the angle of dive. The difference between the force on the axis of motion in the dive and the force on the axis of motion for level flight is your initial excess force that will move the aircraft to its new equilibrium point velocity. The derivative between that and equilibrium is your average excess force along that vector....

Then apply the same formula...

Force = Mass x Acceleration

Rearrange it to solve for Acceleration: The acceleration of gravity is considered constant but acceleration is not constant.

Acceleration = Force/Mass

You then have the aircrafts acceleration rate to the equilibrium point.

Now I am not a computer programmer but I am sure there is a way to look at the code to see if it following those principles.

[JtD]

Originally Posted by Crumpp

It does not answer the original poster's question.

But it does. The original poster asked in the topics title why there are no dive acceleration differences. There aren't because gravity is the same for all planes. As soon as you consider anything else, the dive accelerations are different. Had he asked why all the dive accelerations are different, the question would have required a much more complex answer.
The answer was specifically given to the question asked.

[Crumpp]

The amount of excess thrust determines an aircraft dive acceleration.

The acceleration of gravity is constant but that excess thrust is not constant. It is a characteristic of the design and each aircraft will have a different acceleration in a dive.