the behavior of exhaust gases is remarkably different at atmospheric pressures and at lower pressures or vacuum. One example where this becomes obvious is on pictures like KSC-69PC-413 (http:// www.hq.nasa.gov/office/pao/History/alsj/a11/ap11-KSC-69PC-413HR.jpg) where the luminous exhaust gas has made its way *in* the Saturn V's flight direction for what appears to be almost half the length of the third stage.
What effect exactly is causing this? Is it depending on propellant? Are stages especially prepared to withstand such effects? Has this effect been predicted or was it a surprise to rocket engineers the first time it was observed (probably way before the days of Apollo)?
> the behavior of exhaust gases is remarkably different at atmospheric > pressures and at lower pressures or vacuum. One example where this > becomes obvious is on pictures like KSC-69PC-413 (http:// > www.hq.nasa.gov/office/pao/History/alsj/a11/ap11-KSC-69PC-413HR.jpg) > where the luminous exhaust gas has made its way *in* the Saturn V's > flight direction for what appears to be almost half the length of the > third stage.
> What effect exactly is causing this? > Is it depending on propellant? > Are stages especially prepared to withstand such effects? > Has this effect been predicted or was it a surprise to rocket > engineers the first time it was observed (probably way before the days > of Apollo)?
As I understand it, this effect is due to aerodynamics; a shock wave off parts of the rocket create a low-pressure area into which exhaust gases can flow. The worst effect is usually burnt paint, but the same ducting effect in engine clusters can damage engines that are not adequestly insulated.
On Aug 16, 11:57 am, Jens Schweikhardt <use...@schweikhardt.net> wrote:
> hello, world\n
> the behavior of exhaust gases is remarkably different at atmospheric > pressures and at lower pressures or vacuum. One example where this > becomes obvious is on pictures like KSC-69PC-413 (http://www.hq.nasa.gov/
> where the luminous exhaust gas has made its way *in* the Saturn V's > flight direction for what appears to be almost half the length of the > third stage.
> What effect exactly is causing this? > Is it depending on propellant? > Are stages especially prepared to withstand such effects? > Has this effect been predicted or was it a surprise to rocket > engineers the first time it was observed (probably way before the days > of Apollo)?
> Thanks for any insight!
> Regards, > Jens
It is said that von Braun was surprised and alarmed by the Saturn flame creep.
|
