B757-300 Bipe, anyone?

[Chris707]

Not an official Boeing project, but patented!




Chris

[dragon]

Someone has been using "fun stuff" and not sharing!

Seriously, I can see several of the forum members attempting similar things.  I am actually shocked that Alvis hasn't tried this.  Or has he? B)  

[GTX]

That is just so wrong...but also so right .

Regards,

Greg

[The Rat]

Not an official Boeing project, but patented!

By whom?  

And why?    

[Chris707]

A private individual - was supposed to dramatically reduce total drag...

[Alvis 3.1]

Someone has been using "fun stuff" and not sharing!

Seriously, I can see several of the forum members attempting similar things.  I am actually shocked that Alvis hasn't tried this.  Or has he? B)

I'm disappointed that I didn't myself!  

Oh well...


Alvis 3.1

[rallymodeller]

A private individual - was supposed to dramatically reduce total drag...

I find that hard to believe. Just the induced drag from the struts alone...  

[Chris707]

Yeah, we must remember that inventions don't necesarilyy have to _work_ to be patented, but on the other hand, who knows?

"What the present inventor has realized is, despite all the effort put into designing modern aircraft wings, the low aspect ratio wings of many modern aircraft generate significant induced drag. The inventor has realized that this can be alleviated by providing a drag reduction system (DRS). This is counterintuitive, since it both increases the weight of the aircraft and increases drag, other than induced drag. However, it will be shown that if the supplementary wing of the DRS is given a high aspect ratio, it will cause a large reduction of both the induced drag and the profile drag of the wing of a modern high speed high altitude turbofan powered aircraft with a low aspect ratio wing, such as a Boeing 757-300. This reduction in drag will be much greater than any additional drag added by the DRS, thereby leading to an overall reduction in drag and the possibility of large fuel savings. These fuel savings translate into overall reductions in the operating weight of the aircraft, which more than compensates for the additional weight of the DRS.

It will be appreciated that a number of parameters in the basic aircraft design can be varied considerably. In general, the invention is applicable to high speed, high altitude aircraft, intended for both commercial and military applications. Typical parameters applicable to such aircraft are: a cruising speed in the range Mach 0.6 to 0.9; cruising altitude limits between 30,000 and 50,000 feet; a main wing aspect ratio in the range 7-11; in accordance with the present invention, an aspect ratio for the supplementary wing in the range 15-30; both the main wing and the supplementary wing can have sweep angles in the range 20-50.degree., and note that the wings can be swept both forward as well as backward. The invention is believed particularly applicable to aircraft in the weight range 50,000-1,000,000 lbs. Lift limits on the main wing are based on the maximum take-off weight divided by the wing area, and commonly limits are in the range 110-160 lbs per sq ft; supplementary wing area is usually expected to be in the range of 60-90% of the main wing area.

The example below gives a calculated drag reduction of 29.1%, for a Boeing 757-300 aircraft. This is a medium range airliner. It is expected that application of this invention to a low range aircraft would yield a substantially lower percentage drag reduction; on the other hand, application to a high range aircraft should give a substantially higher percentage drag reduction."

[B777LR]

That looks as if it increases drag. The 753 looks good enough as it is.

[kurly]

but patented!

By whom?  

And why?   [/QUOTE]
orville and wilbur boeing

if the struts are swept and curved at just the right angulation, why wouldnt it work? elmaerle???  

[elmayerle]

Well, I'd love to see the interference drag data for where the struts and wings meet and, while you can mitigate the problems, I'm not sure, without a fair bit of study, that you can eliminate them.

I'd love to see some genuine wind tunnel studies on this.

[John Howling Mouse]

Well, I'd love to see the interference drag data for where the struts and wings meet and, while you can mitigate the problems, I'm not sure, without a fair bit of study, that you can eliminate them.

I'd love to see some genuine wind tunnel studies on this.

Well, heh-heh, build a model and, um, borrow some time in the local wind-tunnel dept. (I'm willing to guess you have access to one!).   ^_^  

[elmayerle]

Eh, LM buys time in other folks' tunnels and the nearest one I know of is some  200 miles to the south-southeast at my alma mater.  *smiles* Sounds like an interseting subject for a doctorial thesis, though.