WeserFlug P.1003 Compared to V-22 Osprey

Chad Irby wrote in message . com...
In article ,
(The Enlightenment) wrote:

Chad Irby wrote in message
. com...
In article ,
(The Enlightenment) wrote:

Chad Irby wrote in message
. com...

Nope. Velocity is velocity, and coming in out of vacuum means those
steel wings are just little flanges out in the Mach-20 airflow waiting
to be melted - or broken off altogether.

Nope. There is someting called a hypersonic L/D (lift to drag ratio).

Yes, there is. And it tells us why those wings would have melted off.
To get enough lift to bounce the Silverbird out of the atmosphere again,
you have to deal with the drag of having it in the atmosphere for a few
minutes. Certainly long enough and hot enough to melt those little
steel wings, as demonstrated by the short X-15 flights with even tougher
alloys at lower speeds.

Thus the Germans had alloys similar to inconel that melted at 1450C
and opperated at 750C as turbine blades. These were inferior in creep
strength but not melting point.

So in other words, even if they used those alloys, the plane would have
come apart or deformed, or he would have had to build them out of much
thicker pieces of metal.

No. You don't understand creep strength. The rate of creep is not
such that it should deform significanty and as I point out Sanger's
silver bird re-enetered at far less than orbital velocity.

All hypersonic aircraft, like the SR71 irrespective of material don't
have fatique problems becuase the heat effectively heat treates
(aneals) any work hardening metal. Titanium, inconel, austenitic
steels all are the same.



I'd say their metalurgy were good enough for Silverbird.

Too bad they never got around to using it. Once again, the design for
the Silverbird had *nothing* in it about high-temp metals - just plain
old stainless steel, which you finally admit is not good enough, after
trying to claim that boiler-type stainless was good enough.

Duh, Stainless steel IS a high temperatue alloy. The chromium
isolates the carbon (which can come out of solution) as chromium
carbide.

There were several German companies around at the time that could
produce high temperature refractory alloys and sold them commercialy.

The problem with the chromium steels was that their characteritics
fell of more rapidly than the nickel alloys over 600C. By the time we
get to around 1000C things are evening up again. At 1400C both are
melting.



Sangers work on re-entry was pioneering and very respectable.

He did almost *zero* work on re-entry. With the machinery he had
available, all he could do was very short tests on shockwave formation.

He did Hypersonic wind tunnel testing.

...on tiny little models of the Silverbird, for less than 30 seconds at
a time, with *no* heat testing, and could not have done any different
with the equipment he had during the war.

Thirty seconds (even 30 milliseconds) is plenty of time to get L/D
ratio data, stability data, center of pressure data and to use
Schlierian photography to image shock waves and to place a few
thermocouples in the model.

You assume NASA tested the shuttle near full scale at hypersonic
speeds.

Clearly the Silver bird concept allowed incremental testing and
development at progressively higher speeds. In many ways it was a
highly testable designe. Everything from sled acceleration, Sled
seperation, and rocket motor lightup at progressively higher speeds.