Horton

[ACE-OF-ACES]

Originally Posted by tools4fools

Maybe another picture will help you see what I am saying?

It clearly shows JUMO 004 with inner wing not swept.

I posted this image above btw.

It appears you missed my post where I explained there is more than one way to correct the cg..

So allow me to quote myself, i.e.

Originally Posted by ACE-Of-ACES

Which means the Germans would have had to add more weight (mass) in front of the cg to maintain the cg

This can be done in several ways

1) Add ballast
2) Change the design (shape) of the plane to add more mass forward

Adding ballast is a 'fudge' and is to be avoided, in that it just adds weight. Where as increasing the wing area adds weight, but at the same time increases lift to offset the extra weight of the heavier than expected engines.

With that said it should be clear that your 'conclusion' is in error..

That being the cg was not affected, by the BMW to Jumo engine swap, because the inner wing was not swept..

Because they could have simply corrected the cg by adding mass installing internal ballast forward of the cg instead of adding mass forward of the cg by sweeping the inner wing forward.

Which is pretty standard stuff that is done all the time.. If I recall correctly, the Bf109 had a 60lb ballast weight installed rear of the cg to compensate for the heavier engines.

As I noted, it is not the optimal way of doing things, but it is an 'easy' way of doing what has to be done.

In that simple physics dictates they would have to correct the cg due to the extra mass of the Jumo behind the cg one way or another

But I digress

As to the 'reason' why the inner wings were swept forward..

I just brought up the possibility that the inner wings were swept as part of the cg correction process.. As in the fillets would add more weight forward of the cg. That and doing it for that 'reason' would agree with what STORMBIRDS said about the 'reason' the wings were swept, i.e. to correct the cg due to the heavier than expected engines.

On that note, up to now you have admitted that the outer wings were swept to correct the cg, but you contend that the 'reason' the inner wings were swept forward was to take advantage of swept wing theory..

Even though most if not all agree that 18 degree sweep is too small to achieve any significant advantage in increasing the critical Mach number..

Which begs the question..

If the Germans fully understood swept wing theory..

Why would they go to all the trouble of sweeping the inner wings forward 18 degree is they knew in advance it would not increase the critical Mach number?

Which did not make any sense to me, so I started doing a little more research and I actually found the 'reason' the Germans swept the inner wings forward..

Granted I still consider STORMBIRDS the.. how did you say it? Qualified Authorities on the subject of the Me262

But as you know, for some reason, they had nothing to say with regards to the 'reason' the inner wings were swept forward, it is almost as if they went out of their way to say nothing. All we know for sure is that when given the chance to give the Germans credit for taking advantage of swept wing theory, they said nothing but to confirm that the outer wings were swept to correct the cg.

But I digress

During my research I did find a source that noted the 'reason' the inner wings were swept forward..

And guess what!

It had nothing to do with the cg or swept wing theory!

http://naziscienceliveson.devhub.com...or-compromise/

Originally Posted by Jenkins, Dennis R.

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.

So to sum it up..

• The outer wings were swept to correct the cg.

• The inner wings were swept to correct the airflow separation.

Neither of which were done to take advantage of swept wing theory

Hope that helps! S!