Ride of the Valkyrie?

The various proposals for the American reply to Concorde were know as the SST. Boeing went as far as building a full size mock up .

Klippy
Are you referring to the XB70 crash?
The F104 got too close to the XB70 wing tip vortex and got flipped upside down over the back of the Valkyrie taking off both its fins.
The XB70 was later shown to be unstable without them so a crash was inevitable.

The Learjet camera plane took a video of it actually happening but it is not on YouTube.
All the planes involved used GE engines and the flight was organised by them but there was some legal debate about who actually gave authority for the XB70 to be used which may explain why the video of the actual mid air collision is not available.

Incredibly sad loss of life.

Have only seen the footage available of the crash from about 35mins onwards in the youtube video and the same clip shortened on liveleak. There are still photgraphs put together I think in sequence-

www.area51specialprojects.com/xb-70_crash_sequence.html

There are some other videos of it in flight etc on these websites

www.unrealaircraft.com/classics/xb70.php
www.dfrc.nasa.gov/Gallery/Movie/XB-70/HTML/EM-0039-01.html

There is a book too- though prolly better buying second hand, price difference is huge lol

www.amazon.co.uk/XB-70-Valkyrie-The-Ride-Valhalla/dp/0760305552

I am still not building it but as I did with the Concorde I will build a test duct.

A 70mm EDF at the front with a long duct squashed down to a rectangular box 210x40mm and exiting through six 28mm diameter nozzles. :ohmy:
Most of the 'box' part has a cross section larger than the fan area but it is easier and lighter to simply follow the scale duct outline.
With a scale inlet added the total duct would be 29" long.
At this size it would mean the completed Valkyrie would actually be quite small just 30" span and 51" long.
It would all come down to how much (or little) thrust 6 individual nozzles generated.

You should always have a plan B.
It I increase the size by a factor of 1.4 (42" span 72" long) I could mount two 70mm fans side by side with each fan feeding 3 nozzles.
As the duct would not go through such a dramatic change in shape it should also be a bit more efficient.

But just at the moment I have had enough of multi EDFs! :woohoo:

A start of the test duct. This is just the 'oblong' bit. The more complex section that changes to a 70mm circle goes on the front.

On the full size the lower edges of the duct have quite a distinct radius on the outside so a fillet has been built in.
The next question is for each nozzle how best to go from a square to circle in the smoothest way.
A bit of origami seems to provide a reasonable solution.

This is just paper. The actual ones will need to be made of something a bit stiffer and just a bit bigger. each nozzle going from an 34x30 oblong to 30mm diam.

The actual FSA of the 70mm EDF is 5543sqmm
The duct itself goes from 6045 to 6090sqmm
Six 30mm diam nozzles have an area that is 76% of the FSA.
This is a bit lower % than recommended but the rather extreme shape of the duct will have significantly greater losses than a simple tube of the same cross section.

Finally at bit more research. The first ZB70 has significant hydraulic problems with several flights terminated early due to hydraulic leaks. The system ran at 4000psi much higher than any other aircraft at the time.
One forced landing resulted from a failure of the undercarriage to extend properly. The main leg bogies not only tipped up 90 degrees but then rotated 90 degrees as well to best fit into the wheel well. So a hydraulic failure was likely to be very serious as there was no gravity back up!

Amazing they got it down in one piece but they did have the advantage of the Rogers dry lake at Edwards AFB with its 12 mile landing surface!

ha ha ha
i wondered how long it would be before a build started.

Tony B wrote: ha ha ha
i wondered how long it would be before a build started.

SNAP!!! hahaha :lol: Knew he wouldn't be able to resist hehe
Nice one Simon

Actually this is not a build.
It is purely a test piece to find out the best way to construct it. It is unlikely it will be used in the flying version - if that ever gets built.
That decision will depend on the answer to these questions (as a minimum!):-
1. Was the test duct easy enough to build that I could contemplate making another one?
2. How much thrust remains when using a sexfurcated (it is a real word ) duct?
and finally
3. Have I found somewhere to put it? (Given that I still don't have any place to store my Concorde :woohoo: )

Having experimented with several different materials for the nozzles the best overall solution appears to be 2mm Depron!

Made up from 4 separate pieces, bending and gluing the Depron to form the circular nozzle is a bit tedious but it is much easier to get the dimensions of the 'square' end to exactly match the duct.

Sexfurcated - sounds rude!
Dictionary.com doesn't like it! -

sexfurcated
- no dictionary results
No results found for sexfurcated:
Did you mean sex

I think you mean bi-furcated ducting, the art of 2 into one pipe, or one into 2 sort of thing

Normal mathematical word for a six-function thing is 'hex' as in hexagon (six-sided fugure), so I would have thought that the word should be hexfurgated, i.e. literally divided into six forks. I've found some mathematical references to hexfurcated on the net, but all I can find on sexfurcated is usage on Forums which would imply that it's not the 'correct' word to use..

Pedantic....yes, but I needed an excuse to get away from the boring admin I'm doing a the moment. :lol: :lol:

Loving the (non-) build thread Q

I just knew this would happen!

The prefixes seem to depend on their origin. I found this list.
Number Greek Latin
1 mono- uni-
2 duo-/di- duo-/bi-
3 tri- tri-
4 tetra- quad-
5 penta- quint-
6 hex- sex-
7 hept- sept-
8 oct- oct-
9 ennea- non-
10 dec- dec-
Which is used seems to depends on the word.
A bifurcated duct (Latin origin) is commonly used so 'sexfurcated' would logically appear to be correct rather than hexfurcated.
The real fun arises in a 9 way branch. "Nonfurcated" which would likely to be taken to mean it didn't branch at all!

Nozzle 'production' under way.

Each nozzle has a 'long' side so the bits are marked.
The 'trial' nozzles in paper and clear plastic.
Paper 4g, plastic 7g Depron 5g.

The test duct with the nozzles added.



The really complex bit will be section from the fan.

To make best use of Depron's light weight I suspect it would be more efficient to make the XB70 bigger, say 30%, giving a 40" span but retain a single 70mm fan. The 6 nozzles could then be built with more taper (nearer to scale) to achieve the 85% of the FSA.

Second clip in this sequence is a Valkyrie with rather hot tyres! -

Quorneng wrote: Actually this is not a build.
It is purely a test piece to find out the best way to construct it. It is unlikely it will be used in the flying version - if that ever gets built.
.....................
.

Soooo..........are you going to do a test fuselage and test wings? :whistle: :lol: :whistle: