XB 70 Valkyrie – Question

[QUOTE=467 sqn RAAF;1975316]according to wiki…

North American had scoured the literature to find any additional advantage. This led them to an obscure report by two NACA wind tunnel experts who wrote a report in 1956 entitled “Aircraft Configurations Developing High Lift-Drag Ratios at High Supersonic Speeds”. Known today as compression lift,

A very brutal solution considering the elegance of a certain European designed Atlantic shuttle….:p

Here:

So they didn’t drag along the runway when it was on the ground 😉

Wasn’t it dubbed a ‘Waverider’ ?????

And, by way of nothing in particular, until the advent of the swing-wing Tupolev Tu-160 ‘Blackjack’, the folding wingtips of the XB-70 were the largest moving surfaces ever fitted to an aircraft.

The record is now held by the folding wings of the Tu-160 ‘White Swan’.

At least that’s what a bloke down the pub told me…… :rolleyes:

Ken

It’s all in the book! *winks*

Thanks guys, the plain and simple to understand and the extreme detail. 😎

according to wiki…

North American had scoured the literature to find any additional advantage. This led them to an obscure report by two NACA wind tunnel experts who wrote a report in 1956 entitled “Aircraft Configurations Developing High Lift-Drag Ratios at High Supersonic Speeds”. Known today as compression lift, the idea was to use the shock wave generated off the nose or other sharp points on the aircraft as a source of high pressure air. By carefully positioning the wing in relation to the shock, the shock’s high pressure could be captured on the bottom of the wing and generate additional lift. To take maximum advantage of this effect, they redesigned the underside of the aircraft to feature a large triangular intake area far forward of the engines, better positioning the shock in relation to the wing.

North American improved on the basic concept by adding a set of drooping wing tip panels that were lowered at high speed. This helped trap the shock wave under the wing between the downturned wing tips, and also added more vertical surface to the aircraft to improve directional stability at high speeds. NAA’s solution had an additional advantage, as it decreased the surface area of the rear of the wing when they were moved into their high speed position. This helped offset the rearward shift of the center of pressure, or “average lift point”, with increasing speeds. Under normal conditions this caused an increasing nose-down trim, which had to be offset by moving the control surfaces, increasing drag. When the wing tips were drooped the surface area at the rear of the wings was lowered, moving the lift forward and counteracting this effect, reducing the need for control inputs.

Enhanced directional stability and reduced wing surface area thus enhancing speed???