Much improved Me 109K?

[dedalos]

Dedalos, there you have it, straight from a combat pilot.
Cleaning up the parasite drag for top speed (straight and level flight) is not going to have that much effect on your energy bleed in a high G, high AOA turning fight, as the relative wind isn't striking the parasite drag features from the angle they were streamlined for, and the huge increase in induced drag from the AOA and G load is going to far outweigh the minor reductions in parasite drag from the aerodynamic cleanup.
Cheers,
Wes

My friend i dont disagree. That s why i wrote "sustained" turn rate. In my ominion no ww2 fighter could make long turns in high g s, high AoA.
What i mean is that i would expect somewhat slower energy bleeding in long , medium angle turns which were often used
Of course mr biff s opinion is far more important than mines. Of course an increase of 60 km/ in F15 is nothing, in Bf 109 is 10% improvement
We do know that the Fw 190D had approximately 9% less drag than than the A model , same wing ,and similar power snd weight. All pilots reported better turning for the D model

 

[XBe02Drvr]

What i mean is that i would expect somewhat slower energy bleeding in long , medium angle turns which were often used

Of what use is a long medium angle turn unless you have enough speed advantage to get out of range before your opponent can pull inside you and get enough lead for a firing solution? Pull hard, go vertical, or get out.
Cheers,
Wes

 

[Ascent]

My understanding of air combat,and please note I was groundcrew not aircrew, is that it's all about energy. You want speed or you want height or ideally both.
If all you're doing is pulling hard you'll quickly burn that energy off. Yes, sometimes you have to pull hard, to get that shot or to lose your opponent, but most of the time you'll surely be trying to maintain or increase your energy?

 

[Ivan1GFP]

My friend i dont disagree. That s why i wrote "sustained" turn rate. In my ominion no ww2 fighter could make long turns in high g s, high AoA.
What i mean is that i would expect somewhat slower energy bleeding in long , medium angle turns which were often used
Of course mr biff s opinion is far more important than mines. Of course an increase of 60 km/ in F15 is nothing, in Bf 109 is 10% improvement
We do know that the Fw 190D had approximately 9% less drag than than the A model , same wing ,and similar power snd weight. All pilots reported better turning for the D model

Hello Dedalos,
I believe X XBe02Drvr already gave a pretty good explanation but maybe it will make more sense if we look at it in a slightly different way.
There is always parasitic drag and unless you happen to be flying a ballistic curve (Zero G), there is some amount of induced drag.
If you are turning the induced drag will be increased over the amount for level flight. If your aircraft is making a turn, it probably won't be going at its maximum level speed either which means the ratio of induced drag to parasitic drag will be higher. In a turn, the airframe probably will not be aligned in a direction for minimal drag either.
These differences combine to make a slight reduction in parasitic drag less important.

There are some other differences between the typical FW 190A and FW 190D series. The power output of the JuMo 213 was actually quite a bit higher than the BMW 801, even as installed in the FW 190A-9. The critical altitude was also about 1 KM higher.

- Ivan.

 

[tomo pauk]

...
There are some other differences between the typical FW 190A and FW 190D series. The power output of the JuMo 213 was actually quite a bit higher than the BMW 801, even as installed in the FW 190A-9. The critical altitude was also about 1 KM higher.

In 1944 and at sea level,, BMW 801D was making bigger power than Jumo 213A - 1900* PS vs. ~1780. At 5.7 km, BMW 801D was good for 1440* PS, the Jumo 213A some 1530 PS.
For higher altitudes the Fw 190D have had a much better layout of ram air intake than usual 190A will have; some 10% less drag due to the change of powerplant, and two cannons less. Exhaust thrust was up to 140 kg for the BMW 801D, up to 175 for the Jumo 213A.
All of this, coupled with a bit better power above 5 km, made the 190D-9 much better than 190A of the era for higher altitudes.

* plus the power to drive the fan

 

[spicmart]

In 1944 and at sea level,, BMW 801D was making bigger power than Jumo 213A - 1900* PS vs. ~1780. At 5.7 km, BMW 801D was good for 1440* PS, the Jumo 213A some 1530 PS.
For higher altitudes the Fw 190D have had a much better layout of ram air intake than usual 190A will have; some 10% less drag due to the change of powerplant, and two cannons less. Exhaust thrust was up to 140 kg for the BMW 801D, up to 175 for the Jumo 213A.
All of this, coupled with a bit better power above 5 km, made the 190D-9 much better than 190A of the era for higher altitudes.

* plus the power to drive the fan

Interesting. What source do you have these exhaust thrust figures from? And what is meant with ram air intake?

 

[tomo pauk]

Interesting. What source do you have these exhaust thrust figures from? And what is meant with ram air intake?

For BMW 801D, exhaust thrust ('Abgasstrahlschub') can be found on the power chart and tables, eg. as found here. Jumo 213A - here.
Ram air intake is the tube (or tubes) that feeds the supercharger with fresh air, benefitting from air rammed on itself because the aircraft is travelling at reasonably high speed. On BMW 801, the two tubes were squished and led between cowling and cylinders. On Jumo 213, a wide, single tube starts at outside of right side of cowling and leads to the swirl throttle. The ram air intake start can be easily seen here, 1st pic, just above rear cylinder exhausts.
Shortcoming of that pronounced ram air intake is that it adds some drag. A token number of BMW 801s were also outfitted with external ram air intakes; it also made possible installing air filters on them.

 

[BiffF15]

My friend i dont disagree. That s why i wrote "sustained" turn rate. In my ominion no ww2 fighter could make long turns in high g s, high AoA.
What i mean is that i would expect somewhat slower energy bleeding in long , medium angle turns which were often used
Of course mr biff s opinion is far more important than mines. Of course an increase of 60 km/ in F15 is nothing, in Bf 109 is 10% improvement
We do know that the Fw 190D had approximately 9% less drag than than the A model , same wing ,and similar power snd weight. All pilots reported better turning for the D model

Dedalos,

Adding power to a fighter is a good thing. You will never hear a fighter pilot complain about that! I also agree that making a combat plane faster is better as well.

It's what you get from or can do with your investment / improvement that's really important. It's late 44 or early 45 in Germany, there are daily raids in your country on whatever target / location your enemy desires. With air superiority (control of the skies). With superior numbers. With superior training. With superior fuels. And all those superiors grow almost daily. A 30% improvement in a Me109 speed and 50% production output increase would not make a noticeable change in daily operations for the Allies or delay the inevitable by more than a few weeks. No fuel and no pilots would negate the production increase and the realistic 10% Me109 speed increase in the reality of a one on one combat would probably be almost unnoticeable.

As previously posted by Ivan1GFP it's the induced drag that is the enemy. The F16 is known for its energy maneuverability (EM). The reason it has such awesome EM is due to A: a clean aerodynamic design and B: most importantly, an aft CG. Reducing parasitic drag makes for a higher top speed at wide open throttle and better fuel mileage at cruise settings. An aft CG means less induced drag per G pulled, or better energy sustainment during maneuvers. An F16s aft CG is so drastic that the plane cannot be flown without the flight control computers.

The reason I brought up the F16 is twofold, one to explain what and why induced drag is important and second the Fw190D. The D model has a longer fuselage with the V12 in front and a plug behind the pilot. There was / is probably a CG shift aft which resulted in a better or improved turn over the radial powered variants. I have no data to validate my hypothesis, just using what I know from experience and reasoning things out. One of the masters of knowledge on here may have the documentation that would validate my theory.

The Me262 had a huge speed advantage over everything the allies had, yet it's effectiveness was combated how? Sending guys to hangout around their airfields to catch them in the pattern, a weakness for them (262s). Or to strafe their fields to destroy them on the ground. Luxuries of the winning or offensive side. The 109 / 190s had tremendous performance due in large part to their being small with a big motor. They had short legs though. The short legs are okay as you are fighting over your country, close to your field. The downside is you are fighting over your country and not your enemies. You are defensive and becoming more so on a daily basis.

Back to the Me109. Adding power is a good thing, but was it the best thing? The plane had some short comings that in my retrospective opinion that would have been more valuable to have fixed. First would be the landing gear geometry so it would be be easier for a new guy to safely checkout and fly it. Second would be aft visibility. I have set in a Mig29, P51, F18, and F16 (plus the Eagle) and hands down the MiG was the absolute worst. By a LARGE margin. More lives would have been saved with that improvement, resulting in more combat effectiveness. If it only saved 1 life per day from mid 43 to 1 Jan 45 it would have resulted in 545 more pilots in a time when you lost a third or more of your fighter pilots every few months. Plus 545 more planes, plus the losses those planes and pilots could have caused.

Just my opinion.

Cheers,
Biff

 

[XBe02Drvr]

it's all about energy. You want speed or you want height or ideally both.
If all you're doing is pulling hard you'll quickly burn that energy off. Yes, sometimes you have to pull hard, to get that shot or to lose your opponent

That's exactly the point. If your opponent is engaged in a medium turn, either in your 12 or in your 6, a brief hard pull can give you lead for a shot (6), or force an overshoot (12), without much drain on your energy. The key to survival is avoid a sustained turning fight unless you have a clear advantage in that arena.
Cheers,
Wes

 

[soulezoo]

That's exactly the point. If your opponent is engaged in a medium turn, either in your 12 or in your 6, a brief hard pull can give you lead for a shot (6), or force an overshoot (12), without much drain on your energy. The key to survival is avoid a sustained turning fight unless you have a clear advantage in that arena.
Cheers,
Wes

Would this be the point where "40 second Boyd" in a F-100 would underscore the point you are making?

 

[llemon]

It'd be nice to see some actually photos or drawings of this K series proposal.

There was an almost innumerable series of improvements studied for the 109 throughout its life. The cockpit went through many different trialed revisions that aren't well documented in most books. Stuff like a retractable tail wheel was almost done on the E series. Main wheel covers were almost put into production in 43. An annular oil cooler was tried on several V series machines. A wooden wing of a different planform with split flaps was trialed. Fences instead of slats. Different vertical stab on the V7. The list just goes on and on.

And then there is all the stuff that was studied but never test flown. A cut down rear fuselage and new canopy. Radiators with a sizeable boundary layer splitter. All sorts of different gun troughs. Its a bewildering list and I'd like to make a proper family tree of all the developments on day.

 

[XBe02Drvr]

Would this be the point where "40 second Boyd" in a F-100 would underscore the point you are making?

Don't know that much about monsieur Boyd, but 40 seconds of sustained high G turn in the lead sled sounds like a recipe for disaster to me.
Cheers,
Wes

 

[soulezoo]

Don't know that much about monsieur Boyd, but 40 seconds of sustained high G turn in the lead sled sounds like a recipe for disaster to me.
Cheers,
Wes

Word is he "wrinkled" more than one bird. Caused one to have hydraulic failure in flight that led to a courts martial. He proved it was an engineering flaw and the case was dismissed.

 

[spicmart]

It'd be nice to see some actually photos or drawings of this K series proposal.

There was an almost innumerable series of improvements studied for the 109 throughout its life. The cockpit went through many different trialed revisions that aren't well documented in most books. Stuff like a retractable tail wheel was almost done on the E series. Main wheel covers were almost put into production in 43. An annular oil cooler was tried on several V series machines. A wooden wing of a different planform with split flaps was trialed. Fences instead of slats. Different vertical stab on the V7. The list just goes on and on.

And then there is all the stuff that was studied but never test flown. A cut down rear fuselage and new canopy. Radiators with a sizeable boundary layer splitter. All sorts of different gun troughs. Its a bewildering list and I'd like to make a proper family tree of all the developments on day.

A radiator with boundary layer suction /splitter was used on the F-series. It wasn't too sizeable though. Not sure why they omitted it with the G-series on. I also would like to see this aerodynamically optimized K-machine.

 

[spicmart]

For BMW 801D, exhaust thrust ('Abgasstrahlschub') can be found on the power chart and tables, eg. as found here. Jumo 213A - here.
Ram air intake is the tube (or tubes) that feeds the supercharger with fresh air, benefitting from air rammed on itself because the aircraft is travelling at reasonably high speed. On BMW 801, the two tubes were squished and led between cowling and cylinders. On Jumo 213, a wide, single tube starts at outside of right side of cowling and leads to the swirl throttle. The ram air intake start can be easily seen here, 1st pic, just above rear cylinder exhausts.
Shortcoming of that pronounced ram air intake is that it adds some drag. A token number of BMW 801s were also outfitted with external ram air intakes; it also made possible installing air filters on them.

Thank you. I will read that thread soon. I know ram air intake under the name supercharger air intake.

What is interesting is that the Jumo 213 versions usually had a bit less power than the comparable version of the DB 603. But propulsion of the Jumo was greater though due to greater exhaust thrust.

 

[llemon]

A radiator with boundary layer suction /splitter was used on the F-series. It wasn't too sizeable though. Not sure why they omitted it with the G-series on. I also would like to see this aerodynamically optimized K-machine.

It was a boundary layer suction device. It was removed because that provided an easy way to increase the radiator area without changing the production tooling that much. Pretty much a drop in change.

 

[Tieleader]

Dedalos,

Adding power to a fighter is a good thing. You will never hear a fighter pilot complain about that! I also agree that making a combat plane faster is better as well.

It's what you get from or can do with your investment / improvement that's really important. It's late 44 or early 45 in Germany, there are daily raids in your country on whatever target / location your enemy desires. With air superiority (control of the skies). With superior numbers. With superior training. With superior fuels. And all those superiors grow almost daily. A 30% improvement in a Me109 speed and 50% production output increase would not make a noticeable change in daily operations for the Allies or delay the inevitable by more than a few weeks. No fuel and no pilots would negate the production increase and the realistic 10% Me109 speed increase in the reality of a one on one combat would probably be almost unnoticeable.

As previously posted by Ivan1GFP it's the induced drag that is the enemy. The F16 is known for its energy maneuverability (EM). The reason it has such awesome EM is due to A: a clean aerodynamic design and B: most importantly, an aft CG. Reducing parasitic drag makes for a higher top speed at wide open throttle and better fuel mileage at cruise settings. An aft CG means less induced drag per G pulled, or better energy sustainment during maneuvers. An F16s aft CG is so drastic that the plane cannot be flown without the flight control computers.

The reason I brought up the F16 is twofold, one to explain what and why induced drag is important and second the Fw190D. The D model has a longer fuselage with the V12 in front and a plug behind the pilot. There was / is probably a CG shift aft which resulted in a better or improved turn over the radial powered variants. I have no data to validate my hypothesis, just using what I know from experience and reasoning things out. One of the masters of knowledge on here may have the documentation that would validate my theory.

The Me262 had a huge speed advantage over everything the allies had, yet it's effectiveness was combated how? Sending guys to hangout around their airfields to catch them in the pattern, a weakness for them (262s). Or to strafe their fields to destroy them on the ground. Luxuries of the winning or offensive side. The 109 / 190s had tremendous performance due in large part to their being small with a big motor. They had short legs though. The short legs are okay as you are fighting over your country, close to your field. The downside is you are fighting over your country and not your enemies. You are defensive and becoming more so on a daily basis.

Back to the Me109. Adding power is a good thing, but was it the best thing? The plane had some short comings that in my retrospective opinion that would have been more valuable to have fixed. First would be the landing gear geometry so it would be be easier for a new guy to safely checkout and fly it. Second would be aft visibility. I have set in a Mig29, P51, F18, and F16 (plus the Eagle) and hands down the MiG was the absolute worst. By a LARGE margin. More lives would have been saved with that improvement, resulting in more combat effectiveness. If it only saved 1 life per day from mid 43 to 1 Jan 45 it would have resulted in 545 more pilots in a time when you lost a third or more of your fighter pilots every few months. Plus 545 more planes, plus the losses those planes and pilots could have caused.

Just my opinion.

Cheers,
Biff

Very well worded. Even enough that a non technical noob like myself could understand.

 

[spicmart]

It was a boundary layer suction device. It was removed because that provided an easy way to increase the radiator area without changing the production tooling that much. Pretty much a drop in change.

Where do you know all these changes/details? I have not often read about such.

 

[Denniss]

What is interesting is that the Jumo 213 versions usually had a bit less power than the comparable version of the DB 603. But propulsion of the Jumo was greater though due to greater exhaust thrust.

35 liter Jumo 213A with ~3200rpm vs 44.5 liter DB 603A with ~2700 rpm

 

[spicmart]

The Fw 190D only had a 500 mm drum to lengthen the rear fuselage and a slightly enlarged tail. Not that much of additional weight. But the Jumo has a radiator installation with an armored ring which should weigh more. Maybe it was just the increased leverage.