Ingame Dive Comparison at 700kph (more interesting than you think)

[6./ZG26_Klaus_Mann]

One day I thought: "How do I best compare how much Energy do the Aircraft loose at Speed and thus the High Speed Drag"

And then I though I will bring them up to 700kph indicated and between 2500 and 500m I took the time and the result should show how much Energy the Aircraft loose at these Speeds. 

 

I made 5 Flights Per Aircraft and took the two best results (With most constant Speed). 

 

Klimov 105: Closed Rads, 1st Gear, 100% Mix

AM-35: Rads Closed, 50% Mix for Normal, 100% for WEP

M-82: Outlet and Oil Closed, 1st Gear, 100% Mix

V-1710: Rads Closed, 37@2600 for Normal, 42@3000 for WEP

DB601A: Rads Closed

DB601Aa: Rads Closed, 2400rpm for both tests

DB601E and DB605A: Automatic

BMW801D: Automatic

 

Bf109E was tested with -80% Stabilizer

All other Bf109s with -100% Stabilizer

Fw190A with -60% Stabilizer

 

The Lower the Number the more efficient it is aerodynamically. I'll not take sides in this, you guys will do the Job of taking sides much better, 

 

 

 

 

 

 

Same test, different altitude, slightly lower IAS, Engines same as above except for 2nd Supercharger Gears. 

 

 

 

 

 

This is Han's advice if you want to use this test as evidence for anything."'we all know what we are talking about"

 

"'we all know what we are talking about"

It's only emotions. No any historical technical documentation like flight tests reports? No any strict comparing between sorces and game? So yes, we know "what we're talking about" - we're talking about emotions, not about strict fact-supported claims.

As I've said many times before, rule is: in my PM box should be a message where will be:

1. Claim detailed decription, which explain all aspects of the claim

2. Supporting historical technical sources like flight manuals, flight test reports and so on, with strict pointing page and line where we should look for proofs

3. Strict flight tests in game, which shows significant difference between game and historical source.

If it is - we start to investigate the claim. Two finals are possible:

1. We provide "our FM is ok" proofs

2. We fix the issue

I'm hope it's clear. And, actualy, it works.

 

110 - same here, compare it by strict tests with tank machinegun or plane turret machinegun where we can count single bullet hits of you single shots to the same part of wing on 110 and Pe-2 for example."

 

Edited September 27, 2016 by 6./ZG26_Klaus__Mann

[LuftManu]

[F/JG300_Gruber]

Interesting.

 

The Fw is the best in this dive contest I see.

I'm very surprised about the F2 performance, and a bit disapointed about the MC202. It seems to be more draggy than it looks.

 

A little thing is that it's not really showing the drag at high speed as you keep the throttle up.

It's more the ability of the aircraft's thrust to compensate for it's drag.

[LuftManu]

Interesting.

 

The Fw is the best in this dive contest I see.

I'm very surprised about the F2 performance, and a bit disapointed about the MC202. It seems to be more draggy than it looks.

 

A little thing is that it's not really showing the drag at high speed as you keep the throttle up.

It's more the ability of the aircraft's thrust to compensate for it's drag.

I wouldn`t say it is, for sure the WEP makes him outstanding but there is not so much diference with other planes 

Edited September 27, 2016 by Ala13_ManuV

[6./ZG26_Klaus_Mann]

Interesting.

 

The Fw is the best in this dive contest I see.

I'm very surprised about the F2 performance, and a bit disapointed about the MC202. It seems to be more draggy than it looks.

 

A little thing is that it's not really showing the drag at high speed as you keep the throttle up.

It's more the ability of the aircraft's thrust to compensate for it's drag.

It's worse than the MiG-3 and 109F-2, in the same realm as the P-40.

The E-7 is surprisingly bad. It's about as bad as an I-16 if it could dive a bit faster. 

Edited September 27, 2016 by 6./ZG26_Klaus__Mann

[coconut]

I don't understand how you made your test. What's the constant(s) here? Certainly the time it takes to go from 2500m to 500m depends on the diving angle, right? What was it? What does this speed of 700km/h mean? At what part of the dive did you reach it? Or is that the speed you maintained through the dive?

[GridiroN]

So, the 190 and the F2 are the most aerodynamically effective planes, and the P40 and the 202 are the worst?

 

Not overly surprising. 

 

I'm more surprised the LA5 did worse than the LaGG considering the LA5 is flies really nicely imo and the LaGG flies like a brick. 

[Dr_Molem]

I'm more surprised the LA5 did worse than the LaGG considering the LA5 is flies really nicely imo and the LaGG flies like a brick. 

 

There was the same debate, a while ago: http://forum.il2sturmovik.com/topic/17423-600kmh-dive-test/?p=275231

[6./ZG26_Klaus_Mann]

I don't understand how you made your test. What's the constant(s) here? Certainly the time it takes to go from 2500m to 500m depends on the diving angle, right? What was it? What does this speed of 700km/h mean? At what part of the dive did you reach it? Or is that the speed you maintained through the dive?

I maintained a constant speed of 700kph from 2500-500m, starting the dive at 6000m. 

You can calculate the Dive Angle from the Vertical Distance and the Hypotenuse is the Speed divided by time. And then you can just calculate alpha. 

 

Anyways, you will find out that at low altitude the 190 has no advantage in a dive over a well flown Yak-1. This is objective and testible. If it's historically correct is not a question I will attempt to answer. 

 

Anyways, I may repeat the test for 4500-2500m and see if the picture changes at a later point. 

So, the 190 and the F2 are the most aerodynamically effective planes, and the P40 and the 202 are the worst?

 

Not overly surprising. 

 

I'm more surprised the LA5 did worse than the LaGG considering the LA5 is flies really nicely imo and the LaGG flies like a brick. 

 

It does better using Forsazh. I'm really surprised by the F-2 though. 

Edited September 27, 2016 by 6./ZG26_Klaus__Mann

[GridiroN]

 

It does better using Forsazh. I'm really surprised by the F-2 though. 

 

The F2 doesn't surprise me; it is noticably smoother ride than the F4. It's only weakness is it's inability to climb with the F4 and G2. 

 

I actually view the 15mm cannon and upgrade over the 20 because both guns suck, but at least the 15 is more accurate. You can put a lot of rounds in a plane from a distance with it. 

[6./ZG26_Klaus_Mann]

I don't understand how you made your test. What's the constant(s) here? Certainly the time it takes to go from 2500m to 500m depends on the diving angle, right? What was it? What does this speed of 700km/h mean? At what part of the dive did you reach it? Or is that the speed you maintained through the dive?

 

Well, just like Rate of Climb is an indicator for the straight line acceleration, this indicates the way the machines will be able to seperate in a Dive. 

My Low Altitude Test strongly indicates that a 190 will not be able to get away from a Yak except when going at absolute Dive Limit. At altitude the gap is minute. 

Unfortunately there is no way to test acceleration along an angle, so we will have to make due with the curves from this kind of test with values we can actually measure. 

 

 

 

[III/JG2Gustav05]

Bf109F2 actually is not good like it shown here. what I experienced in practice is that F2's engine is very easily to get overheat and the radiators open more widely than F4 and G2 which impacts its dive acceleration dramatically.

[II./JG77_Manu*]

I actually view the 15mm cannon and upgrade over the 20 because both guns suck, but at least the 15 is more accurate. You can put a lot of rounds in a plane from a distance with it. 

 

Another indication that the German 20mm is completely borked. Germans deemed the Mg151/20 a huge upgrade over the former. 

[LittleJP]

Could you measure the time to reach say, 700 km/h IAS from 6000 m? I suppose the difficulty would be setting a constant angle of dive. Acceleration would be the big determining factor, if the 190 can accelerate much faster, it will still indeed be able to pull away.

[6./ZG26_Klaus_Mann]

Could you measure the time to reach say, 700 km/h IAS from 6000 m? I suppose the difficulty would be setting a constant angle of dive. Acceleration would be the big determining factor, if the 190 can accelerate much faster, it will still indeed be able to pull away.

As I said, you can calculate the acceleration of an Aircraft by knowing it's rate of climb/sink at a number of speeds. Obviously the better an aircraft climbs at a certain speed, the better it accelerates through that speed. 

This test at 700kph tells you that through 700kph the Yak-1 and Fw190 have the same acceleration. 

[Asgar]

As I said, you can calculate the acceleration of an Aircraft by knowing it's rate of climb/sink at a number of speeds. Obviously the better an aircraft climbs at a certain speed, the better it accelerates through that speed.

This test at 700kph tells you that through 700kph the Yak-1 and Fw190 have the same acceleration.

Ok, I'm a little slow today. How can you have acceleration at a constant speed?

[6./ZG26_Klaus_Mann]

Ok, I'm a little slow today. How can you have acceleration at a constant speed?

Imagine the Acceleration of anything, a car, boat or airplance in a straight line as a Curve. Now by doing constant Speed Tests and measuring the vertical velocity you can basically create a tangent on that curve and know the acceleration at that exact point. 

 

It's a couple of Derivations I am too lazy to make. 

 

Anyways, think of it like that: In Level flight some Aircraft does 350 at maximum power. Above that speed it decelerates, below that speed it accelerates. 

If you climb at 250, the excess power that would normally propell you to 350 is now used to create an upward force. That Upward force is the same as it would use to accelerate the aircraft above 250 in a straight line. 

So basically, when you know how well you aircraft climbs at a given speed, you know how well it accelerates at that speed. Same for a Dive. 

 

So basically, by testing dives and climbs at constant speed I can calculate the acceleration of the aircraft at that exact speed as a Tangent on a Curve. 

[Asgar]

Ah ok. Thanks

[LittleJP]

I'm guessing tests would need to be done to get rate of sink for speeds ranging from say, 300 km in 50 km/h increments up to 650

[JG13_opcode]

Hmmm, thanks for doing this.

 

Question: if the aircraft are all diving at different angles, is a comparison meaningful in the tactical sense?

 

If I want to know if my Yak will catch the 190 diving away from me, shouldn't I test the two diving side-by-side, or perhaps one following the other as opposed to each of us diving at whatever angle happens to hold 700 km/h IAS?

Edited September 28, 2016 by JG13_opcode

[Matt]

I'm a bit tired and might not be thinking straight right now, but if you would test the acceleration in level flight (using the handy auto-level feature), wouldn't that give the same relative acceleration difference between the planes which could also be used to compare the relative acceleration in a dive and wouldn't that be much more accurate? Of course you can't reach those high speeds in level flight, but for comparison sake, that wouldn't matter, because the maximum air speed is the limiting factor.

Edited September 28, 2016 by Matt

[II./JG77_Manu*]

I'm a bit tired and might not be thinking straight right now, but if you would test the acceleration in level flight (using the handy auto-level feature), wouldn't that give the same relative acceleration difference between the planes which could also be used to compare the relative acceleration in a dive and wouldn't that be much more accurate? Of course you can't reach those high speeds in level flight, but for comparison sake, that wouldn't matter, because the maximum air speed is the limiting factor.

 

No, we don't have vacuum here. Dive acceleration is in no way connected linearly to level flight acceleration

[coconut]

Hmmm, thanks for doing this.

 

Question: if the aircraft are all diving at different angles, is a comparison meaningful in the tactical sense?

 

If I want to know if my Yak will catch the 190 diving away from me, shouldn't I test the two diving side-by-side, or perhaps one following the other as opposed to each of us diving at whatever angle happens to hold 700 km/h IAS?

 

In the case of the Yak and the FW, they moved at the same speed (700km/h), their vertical displacement is the same (2000m) and the time is the same (60s). From that I expect they should have dived at the same angle (hypotenuse is the same length, vertical component is the same too).

 

For the FW vs Yak debate, it could be interesting to go beyond 700km/h. I'm pretty sure I've dived at faster speeds than that when I had the altitude in a FW190. I would worry about following that in a Russian plane. Last time I did that in a Mig I lost a number of control surfaces.

 

Still, it's relevant when attempting a shallow dive to escape, as this means it probably won't work.

[6./ZG26_Klaus_Mann]

In the case of the Yak and the FW, they moved at the same speed (700km/h), their vertical displacement is the same (2000m) and the time is the same (60s). From that I expect they should have dived at the same angle (hypotenuse is the same length, vertical component is the same too).

 

For the FW vs Yak debate, it could be interesting to go beyond 700km/h. I'm pretty sure I've dived at faster speeds than that when I had the altitude in a FW190. I would worry about following that in a Russian plane. Last time I did that in a Mig I lost a number of control surfaces.

 

Still, it's relevant when attempting a shallow dive to escape, as this means it probably won't work.

Exactly. The Dive Limit on the Yak is 720. 

[Gump]

HOWEVER, it is common to be caught in a 190 by diving too steeply (fast) and the yak catches up a little later by diving a bit more shallow (fast for a longer time), because the 190 will slow down. you might say, "then dont try to outrun in a straight line". but if you turn the 190 it bleeds speed horribly and then you are within range of the yak's turning advantages.

[6./ZG26_Klaus_Mann]

HOWEVER, it is common to be caught in a 190 by diving too steeply (fast) and the yak catches up a little later by diving a bit more shallow (fast for a longer time), because the 190 will slow down. you might say, "then dont try to outrun in a straight line". but if you turn the 190 it bleeds speed horribly and then you are within range of the yak's turning advantages.

Basic Energy Trap. I no longer trap into those, but it's disconcerting anyways knowing that I wont get away from a Yak in a Dive. 

[Capt_Stubing]

Basic Energy Trap. I no longer trap into those, but it's disconcerting anyways knowing that I wont get away from a Yak in a Dive. 

+1 I couldn't agree more.  The only way I've been able to get away from a Yak without forcing a scissors is to cruise climb and hope he loses interest or someone scrapes him off.  Purely anecdotal   but it is my experience many times

[=EXPEND=13SchwarzeHand]

I made 5 Flights Per Aircraft and took the two best results (With most constant Speed).

 

Interesting results Klaus,

 

If you take up the Yak, FW 190 comparison again, you can see that they have nearly equal aerodynamic efficiency in your test.

 

In this test,

 

http://forum.il2sturmovik.com/topic/17423-600kmh-dive-test/?p=275231

 

which is essentially (not entirely) the same set up, but with a pre-patch FW 190, AFAIK the FW did have an advantage over the YAK.

 

So the aerodynamic change that causes the two planes to have equal dive characteristics IMHO is the discussion that is currently going on with the CM tests, since the aerodynamic change is based on these documents. If you look at the two test results just based on an ordinal scale type ranking, the only one that falls out place is the post/pre-patch FW 190. As a result, I hope that the discussion regarding the Clmax implementation will also affect this aspect of the FM.

Edited October 5, 2016 by II/JG17_SchwarzeDreizehn

[Trinkof]

I am quite surprised with the mc 202, I don't know much about aerdynamic physics but I recall the mc202 was well known for its very good aerodynamic and "clean" profile .

[II./JG77_Manu*]

I am quite surprised with the mc 202, I don't know much about aerdynamic physics but I recall the mc202 was well known for its very good aerodynamic and "clean" profile .

That's right. Something you can read all around. It was known to be aerodynamically cleaner then a 109. However dive acceleration is not only about aerodynamics, it's also about engine power, total weight, and weight/drag. Mostly weight/drag