Author Topic: Watching a rocket motor in action  (Read 4397 times)

Offline Peter B

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Watching a rocket motor in action
« on: September 25, 2012, 10:45:25 PM »

Offline Trebor

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Re: Watching a rocket motor in action
« Reply #1 on: September 26, 2012, 07:36:48 PM »
He has some remarkable videos there, I really like the super-critical CO2 experiment he did.

Offline ka9q

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Re: Watching a rocket motor in action
« Reply #2 on: September 26, 2012, 07:58:06 PM »
Yes, I've been following him for some time; he does a lot of neat stuff in his workshop. And I also loved his supercritical CO2 experiments. I first saw supercritical CO2 in the London Science Museum and was amazed. It was almost like a magical disappearing act as the temperature was increased above the critical point and the miniscus simply disappeared.

Oh, to connect this to Apollo, H2 and O2 were both stored in the Service Module as supercritical fluids. By avoiding a liquid phase, the tanks could slowly empty without blobs of liquid floating around in zero gravity. They could still "stratify" into regions of different densities due to temperature variations, which is why the fans were added to periodically stir the tanks. This wasn't necessary to extract gas from the tanks but to improve the accuracy of the capacity readings done with capacitive sensors. Damaged wiring to these fans shorted and caught fire during the Apollo 13 explosion, rupturing one tank and damaging the other.
« Last Edit: September 26, 2012, 08:01:24 PM by ka9q »