[ExI] Skylon heat exchangers

[spike]

>... On Behalf Of Keith Henson
Subject: [ExI] Skylon heat exchangers

On Fri, Dec 19, 2014 at 4:00 AM,   "spike" <spike66 at att.net> wrote:

snip
>
>>... The next trick they must have solved is figuring out how to make this 
> heat exchanger stand up to a shock wave.  Now that's technology 
> indistinguishable from magic.

>...The heat exchangers are not exposed to the shock wave.  The air goes
through two shock waves on the way into the engine so it's all subsonic when
it goes through the heat exchanger... Keith

Keith after two oblique shock waves the air flow is so turbulent they might
be better off facing supersonic flow.  But if they can make this work, it
will be the biggest breakthrough in space technology in my lifetime.  I am
cheering for them.

Here's why I haven't completely lost faith in the whole notion, an
experiment you can do at home.  Go get a garden hose and find a spider web.
Check out how much flow you can spray at that web and still it stands.
Every notion I have about flow and strength of materials would tell me there
is no way that web could hold up to a garden hose, even with a nozzle on it,
but it does.  Now don't take my word for it; go out there and start
spraying.  I have no equations that would explain why the heck that happens.

spike