Horton

[ACE-OF-ACES]

Originally Posted by Crumpp

So..

You are saying that you know more about the Me262 development than..

• STORMBIRDS who build replicas of them..

• Dennis Jenkins who has written more aerospace books that most people own..

And now your including the people who actually tested the Me262 after the war?

Interesting..

Again, don't take this personal

But Ill have to stick with what 'they' said wrt the reason the Me262 wings were swept over what 'you belive' the reason was the Me262 wings were swept.

That is to say we will have to agree to disagree that you know more about the Me262 development than those people know.

S!

[Crumpp]

Most if not all agree the 18.5 was too slight to achieve any real significant advantage in the mach number..

Who is most??



I guess Stormbirds never picked up a calculator and I am sure you are focusing on minutiae taking Jenkins out of context to fit your agenda.

In otherwords, if someone asked Jenkins if the ME-262 benefited from 18 degrees of sweep angle, he would pick up a calculator and say:

Our critical Mach number is raised by reciprocal of the cosine of the angle of sweep. So for 18 degrees of sweep we see a 1.05146 increase to critical mach.

So mach limit of Mach .8 becomes a new limit of .84.

Now at sea level that is represents a 30mph increase in speed!

Now the drag reduction is proportional to cos^2<angle of sweep>

Or a 9.5% reduction in drag.....

Not a bad call on the part of Mtt to add 18 degrees sweep based off their advanced knowledge of swept wing theory. By keeping the sweep moderate, they certainly avoided all the stability and control issues found with sweep angles and engine nacelles.

What is your opinion based on again?

[ACE-OF-ACES]

Originally Posted by Crumpp

I guess Stormbirds never picked up a calculator

So what part of ..

we will have to agree to disagree that you know more about the Me262 development than those people know

Are you still struggling with?

[Crumpp]

I will repost these for readers to access....

[ACE-OF-ACES]

And I might as well repost these for readers to access....

Originally Posted by STORMBIRDS

it is true (as some writers seem intent on repeating loudly and often) that the Me 262s swept wing design was due to the need to adjust the center of gravity for the aircraft

Originally Posted by Dennis R Jenkins

The third prototype was the first Me 262 to fly on jet power alone, taking off on 18 July 1942 with two pre-production Jumo 004A-0 engines. The 12-minute flight reached an altitude of just over 6,000 feet and a speed of 375 mph. A second flight later the same day lasted 13 minutes and reached 11,000 feet and 450 mph. One problem that was immediately evident was that, in a bank, the airflow broke away early from the wing center section. A small fillet was added between the fuselage and engine nacelle, increasing the root chord and continuing the leading-edge sweep angle of the outer panels across the entire center section. This completed the change necessary to give the appearance of a truly swept wing.

Note not my opinion.. Just agreeing with what they said

[Crumpp]

Here is some good infomation on flying wings too.....

You are saying that you know more about the Me262 development than..

Not at all. I am saying what the AIAA relates from the scientist and engineers involved.

I am also demonstrating the benefits as per what is now accepted performance calculations for swept wing aircraft. You know, the stuff Von Karman talks about in his letter?

They are ahead of us on a few items which I will mention. The Germans have been doing extensive work on high speed aerodynamics. This has led to one very important discovery. Sweepback or sweepforward (sic) has a very large effect on critical Mach No.

http://forum.1cpublishing.eu/showpos...&postcount=155

I am saying:

You are focusing on minutiae and twisting it fit your agenda.

Our critical Mach number is raised by reciprocal of the cosine of the angle of sweep. So for 18 degrees of sweep we see a 1.05146 increase to critical mach.

So mach limit of Mach .8 becomes a new limit of .84.

Now at sea level that is represents a 30mph increase in speed!

Now the drag reduction is proportional to cos^2<angle of sweep>

Or a 9.5% reduction in drag.....

Not a bad call on the part of Mtt to add 18 degrees sweep based off their advanced knowledge of swept wing theory. By keeping the sweep moderate, they certainly avoided all the stability and control issues found with sweep angles and engine nacelles.

What is your opinion based on again?

[ACE-OF-ACES]

Originally Posted by Crumpp

Not at all.

Ah good so you agree with what STORMBIRDS and Jenkins said wrt the reason the Me262 wings were swept

Better late than never!

Anyway, it's late

Glad to see you comming around!

S!

[Crumpp]

The third prototype was the first Me 262 to fly on jet power alone, taking off on 18 July 1942 with two pre-production Jumo 004A-0 engines. The 12-minute flight reached an altitude of just over 6,000 feet and a speed of 375 mph. A second flight later the same day lasted 13 minutes and reached 11,000 feet and 450 mph. One problem that was immediately evident was that, in a bank, the airflow broke away early from the wing center section. A small fillet was added between the fuselage and engine nacelle, increasing the root chord and continuing the leading-edge sweep angle of the outer panels across the entire center section. This completed the change necessary to give the appearance of a truly swept wing.

Where does this saying anything about Mtt not understanding swept wing theory or the Me262 not benefiting from its 18 degrees of wing sweep over a straight wing??

You do know there are other methods of fixing this problem, don't you? It could have easily been fixed with twist.

Mtt did not have add the filet and increase the sweep.

Mtt was already flying the Me163 and started the design work on the P1101 variable geometry wing.

You certainly can make some great leaps of logic off a few lines of text.

[Al Schlageter]

Originally Posted by Crumpp

Mtt was already flying the Me163 and started the design work on the P1101 variable geometry wing.

First flight of the Me 163A V4 in 1 September 1941.

Only nine days after the specification was issued by the RLM (July 24, 1944), the first Me P.1101 had taken shape on paper.

Me262 pg 66 Smith/Creek
"By Feb 1940, the design of the P1065 had been modified to have the outer wings swept back some 18 degrees. Originally this was done to solve problems that heavier engine weights estimates were causing with the positioning of the aircraft's center of gravity."

It would seem someone has trouble with dates.

[ACE-OF-ACES]

Originally Posted by Crumpp

Where does this saying anything about Mtt not understanding swept wing theory

Ah I see where you are confused..

As far as I know, nobody in this thread has stated the Germans knew nothing about swept wing theory..

About the only thing that was pointed out on that subject is the Germans did not fully understand swept wing theory..

As you your self admited when you said

Originally Posted by Crumpp

Nobody fully understood swept wing theory until after the war.

Hope that helps!

S!