delcyros
Tech Sergeant
Swept back wings....
Not that surprising. You have to differ between accidently (as can be seen on the Me-262 A), forced by constructionlayout (XP-55,56 and the flying wing) and INTENTIONALLY because of better high speed figures.
Swept back wings can be found of planes from 1910 (dunne, swept back wing biplane). Dr. Lusser formulated in 1935 for the first time that swept back wings would shift the increasing drag to higher Mach figures (so it delayed the max drag, it doesn´t reduce it!)
Look at the XP-56 picture. the swept back wing design is necessary because of the rudders on the wingtips. They have to be put as far back as possible, that forced to use a swept design.
flying wing designs even depend more on the swept back wing (in order to offer at least a bit of stability).
There are also some problems with the swept back wing layout, which made this design unattractive for most aircraft designers until 1946:
1.) Increased weight
2.) Considerably less lift (thanks to a thinner wing)
3.) Reduced low speed and stall behavior (higher stall speed)
The last point was to be the most concerned, either wing boundary layers (tested by DVA in 1944) or leading edge slots reduce these effects greatly.
The first designs to deal with these problems for specificly high speed swept wings are:
1.) Me-163 A/B (because of the tailles layout) -1941
2.) Me-262 A (accidently because of the heavier Jumos and shifted center of weight) -late 1942
3.) Me-262 HG I (with more swept back wing inlet for better high speed figure) -1944
4.) Ho-IX (forced by flying wing construction layout) -1944/45
5.) Ju-287 (forward swept wing for better high speed figures) -1944
6.) Ho-XIIIa (60 degrees swept back wing glider for low speed tests)
7.) Me-262 HG-II (35 degrees swept back wing for better high speed figures) -1945 (not flown)
8.) Me-263/Ju-248 (because of the tailles design and because of better high speed figure) -1945
9.) Me-P.1101 (with variable wing swept) -1945 (not flown)
While it is true that US aerodynamics studied swept wings in 1945 (10 years after Lusser), designers refused to adopt the idea for their high speed jets (P-80, P-84 and the very first P-86) because of the risks of worse low speed handling. Acces to german aerodynamic research proved to be vital for overcoming the shortcomings of a swept wing that fast in UK/US/SU and Sweden...
Not that surprising. You have to differ between accidently (as can be seen on the Me-262 A), forced by constructionlayout (XP-55,56 and the flying wing) and INTENTIONALLY because of better high speed figures.
Swept back wings can be found of planes from 1910 (dunne, swept back wing biplane). Dr. Lusser formulated in 1935 for the first time that swept back wings would shift the increasing drag to higher Mach figures (so it delayed the max drag, it doesn´t reduce it!)
Look at the XP-56 picture. the swept back wing design is necessary because of the rudders on the wingtips. They have to be put as far back as possible, that forced to use a swept design.
flying wing designs even depend more on the swept back wing (in order to offer at least a bit of stability).
There are also some problems with the swept back wing layout, which made this design unattractive for most aircraft designers until 1946:
1.) Increased weight
2.) Considerably less lift (thanks to a thinner wing)
3.) Reduced low speed and stall behavior (higher stall speed)
The last point was to be the most concerned, either wing boundary layers (tested by DVA in 1944) or leading edge slots reduce these effects greatly.
The first designs to deal with these problems for specificly high speed swept wings are:
1.) Me-163 A/B (because of the tailles layout) -1941
2.) Me-262 A (accidently because of the heavier Jumos and shifted center of weight) -late 1942
3.) Me-262 HG I (with more swept back wing inlet for better high speed figure) -1944
4.) Ho-IX (forced by flying wing construction layout) -1944/45
5.) Ju-287 (forward swept wing for better high speed figures) -1944
6.) Ho-XIIIa (60 degrees swept back wing glider for low speed tests)
7.) Me-262 HG-II (35 degrees swept back wing for better high speed figures) -1945 (not flown)
8.) Me-263/Ju-248 (because of the tailles design and because of better high speed figure) -1945
9.) Me-P.1101 (with variable wing swept) -1945 (not flown)
While it is true that US aerodynamics studied swept wings in 1945 (10 years after Lusser), designers refused to adopt the idea for their high speed jets (P-80, P-84 and the very first P-86) because of the risks of worse low speed handling. Acces to german aerodynamic research proved to be vital for overcoming the shortcomings of a swept wing that fast in UK/US/SU and Sweden...