wing area

[Shortround6]

Something to remember is that a lot of aircraft designed in the 1930s were designed without much in the way of wind tunnel data. There were few full full sized wind tunnels so a lot of the data was from scale models and there was always some discrepancy when things were scaled up. It some cases they were designing on theory and faith. Also 1000hp was a very powerful engine in the Mid 30s and any extra performance could only be had by keeping drag to a minimum. It turns out you can get a straight taper wing to come within a few percent of the elliptical but the only way to prove it in the 1930s would have been to build another plane with the straight taper wing and try it.
Plenty of other designers spent thousands of hours and tens of thousands of 1930 dollars trying to save 2-3% in drag (some estimate that is what the coupled engines of the He 177 saved over separate engines).

 

[Julian_S]

Thanks for the replies regarding the Spitfire wing planform. (saves using the word 'ellipse!' )

Back on topic regarding wing size, I guess the 109 with it's leading edge slats had, in effect, a variable size wing. ie a wing that is good at the top end of the speed envelope but will 'hang on better' at higher angles of attack nearer the stall.

Julian.

 

[stona]

just had to poke that cat again didnt you....lol

I honestly don't care or know which a Spitfire is. I just keep reading things like the comment above from one of the design team which lead me to an unbiased conclusion about what they thought it was

Anyone with "Spitfire the History" might like to read the chapter "Variation of the Theme" in which a description of the wing for a two seater "almost identical to" F37/34,the Spitfire prototype K 5054 is given as.

"The cantilever wing consists of a single light alloy spar situated near the point of maximum thickness. To this spar is attached the torsion resisting leading edge box and the trailing ribs."

The copy was referenced RJM and BMS,that's Mitchell and Shenstone. If they didn't know then noone does

I really don't have a dog in that fight.

That quote just happened to be in the paragraph I quoted and wasn't what I was looking for.

Cheers

Steve

 

[CobberKane]

My understanding is that a smaller air frame means less drag, less material used in production and lighter weight. The downsides are reduced options in future development (where to put the increased armament or fuel capacity) and degraded handling as power increases. The example of the 109 vs Spitfire offers some insight here, both being comtemporanious for the course of the war. Neither changed much in terms of wing area and both increased markedly in weight and power
but only the die-hard 109 fans (hi guys!) would maintain the German fighter handled the upgrades anything like as well as the larger Spit. I believe that towards the end of the war the Germans gave serious consideration to putting the Re 2005 (another fighter with an 'elliptical' wing) into production because they considered its larger airframe better able to handle the increasing power of the later Daimler engines than could the 109.
On the subject of the elliptical wing, I suspect the Spitfire was somewhat more than the sum of its parts, and whether Mitchell intended it or not the aircraft owed it exemplary handling at least in part to its wing design. I'm sure the subject has been done to death, but what was the rationale behind the design of other aircraft with a similar planform? The Aichi D3A, the P-47, the Re 2002/2005? Topic for anothre thread...?

 

[krieghund]

With He-219 Heinkel was maybe going for too small a wing? He-112 100 were also featuring small wings.

Had the He100 commenced production plans were in the making to increase the span from 9.42m to 10.8m and wing area increasing from 155.7 ft2 to 178.6 ft2 and engine upgrade to Db601N(M) then to Db601E(M). I have a graphic of the new wing but not permission from the owner yet to release it.

 

[stona]

Thanks for the replies regarding the Spitfire wing planform. (saves using the word 'ellipse!' )

Back on topic regarding wing size, I guess the 109 with it's leading edge slats had, in effect, a variable size wing. ie a wing that is good at the top end of the speed envelope but will 'hang on better' at higher angles of attack nearer the stall.

Julian.

Yes,but the slats don't really work by increasing wing area. There effect is a rather complicated sum of several aerodynamic phenomena which I can't remember

They do have the overall effect you describe.

Cheers

Steve

 

[R Pope]

If you foreshorten the Spit wing planform so the span is about the same as the spar thickness, you have a very close approximation of the airfoil.This means that the same downscaled airfoil shape could be used all the way out to the tip, greatly easing the designer's workload. Of course, the airfoil changes slightly from root to tip, to make the roots stall first for one reason, but the basic form still makes it easier.
The "elliptical" wing shape was probably influenced by the He70 purchased by Rolls Royce as an engine test bed in the mid-30's.

 

[drgondog]

The Spitfire plan form eveolved from first 'elliptical' to squeeze out as much induced drag as possible and second - stretched the chord on that thin wing so that a 20mm gun could be installed - for the latter the Thickness over Chord ration stayed the same but lengthening the chord gavi it room to grow for height within the wing.

As to the question posed by the Post - 'small versus large' has two cmponents. Drag and Manueverability performance. Look to W/L of the original design to get a better idea of the manueverability versus drag trade offs the designers were looking for.

You can get a big wing and lots of climb and turn - but it might not go fast or far.

 

[stona]

The "elliptical" wing shape was probably influenced by the He70 purchased by Rolls Royce as an engine test bed in the mid-30's.

Apparently not. It was ressurected from a much earlier (1929) wing designed by Mitchell and combined with the new aerofoil profiles brought back from the US by Shenstone and Westbrook in 1934. It then evolved from a precise elliptical design as a result of various pressures,undercarriage,armament and ease of manufacture being foremost.
The He 70 was used extensively for cooling and exhaust system trials and certainly influenced these,particularly the radiator design,on the Spitfire. Supermarine were also impressed with the overall smooth finish of the Heinkel.
Cheers
Steve

 

[davebender]

Why did Hungary prefer the He-112B over the He-100?

Original He-112 would have been expensive to produce. I've got to assume some of the cost reduction techniques used for the He-100 were incorporated into He-112 variant Hungary wanted to produce.

 

[tomo pauk]

He-112 was in production prior ww2, the He-100 was not. Once Hungarians figured out that He-112 was not the best the fighter in the world, they were not allowed to buy neither DB-601A, nor Jumo 211. Without such engines, the He-100 won't take off (no pun intended). Eventually, Hungarians started to buy Italian fighters, and later in war, Bf-109.