4 ms·

That will push water directly opposite of the thrust. I expect the water to be pushed backwards, the plate to melt and the exaust to be pushed into the water ta

That will push water directly opposite of the thrust. I expect the water to be pushed backwards, the plate to melt and the exaust to be pushed into the water tank and maybe we will see a steam explosion. There is a reason flame diverters are diverters instead of blockers. It's much much easier to just throw the exaust to the side instead of trying to fight it head on. Don't try to use force to block it, put a 45 degree angle and use geometry and physics to your advantage. If they really want to experiment with unconventional solutions they could make a small scale test with a spent F9 and see if the idea is feasible. For what it's worth, even the F9 uses a flame diverter trench. I get why they don't want to. It probably means modifying the tower too, probably to make it taller. But I foresee this shower head plate going badly.

kortilla 3y ago
The F9 uses the flame diverter trench because the pad it launches from already has it. Not because spacex built it. They don’t need to test with a spent F9. They already did with raptor engines blasting a steel plate in mcgregor.
- alexvoda 3y ago
  But why would you ever put the plate at 0° when you can put it at 45°. Yes you need some height, but is that so onerous? I am not saying they have to build something equivalent to the SLS/SST/Satun/Soyuz/Proton concrete pad infrastructure. Just put a 45° angle. Wedge, cone, pyramid, whatever shape works. Make everything out of steel if it works and is cheaper. Even RocketLab with their tiny Electron have a diverter. You can see it here: https://youtu.be/P_tGKxL6CLI?t=31 https://youtu.be/P_tGKxL6CLI?t=31
inglor_cz 3y ago
AFAIK flame diverters at Boca Chica would be technologically very challenging because of high ground water level, that is why they try other solutions.
- alexvoda 3y ago
  You don't need to dig to make the diverter. You can also build upwards. And I don't think you even have to make it of concrete. But from the tiny (Electron) to the super heavy (Saturn, N1, SLS) they all used some form of diverter. It doesn't have to be over engineered like the ones built by NASA. Even the Relativity Terran 1 which only ever launched once had a diverter. Since the Super Heavy and the Starship are lifted into place by the tower instead of being rolled already assembled or rolled and erected from horizontal, it would be far easier for Super Heavy to have an above ground diverter compared to other rocket systems because it is no longer necessary to build the artificial hill and ramp on which to roll it. But the diverter is still needed.
  - Gwypaas 3y ago
    > You don't need to dig to make the diverter. You can also build upwards. And wait years for the soil to settle.
    - alexvoda 3y ago
      You did not read the rest of the comment.
mhio 3y ago
Raptor vs water+steel https://www.youtube.com/watch?v=gPd6zYFLBqk https://www.youtube.com/watch?v=gPd6zYFLBqk
- alexvoda 3y ago
  That paragraph was hyperbolic sarcasm which I hoped would have been made clear by suggesting the tank would explode. Note that even in the test you linked the plate was angled. This is not done just to redirect heat but in order too redirect the sound: https://physics.byu.edu/docs/publication/4678 https://physics.byu.edu/docs/publication/4678 Reflecting that towards the engines is probably suboptimal.

kortilla 3y ago

The F9 uses the flame diverter trench because the pad it launches from already has it. Not because spacex built it. They don’t need to test with a spent F9. They already did with raptor engines blasting a steel plate in mcgregor.

alexvoda 3y ago
But why would you ever put the plate at 0° when you can put it at 45°. Yes you need some height, but is that so onerous? I am not saying they have to build something equivalent to the SLS/SST/Satun/Soyuz/Proton concrete pad infrastructure. Just put a 45° angle. Wedge, cone, pyramid, whatever shape works. Make everything out of steel if it works and is cheaper. Even RocketLab with their tiny Electron have a diverter. You can see it here: https://youtu.be/P_tGKxL6CLI?t=31 https://youtu.be/P_tGKxL6CLI?t=31

inglor_cz 3y ago

AFAIK flame diverters at Boca Chica would be technologically very challenging because of high ground water level, that is why they try other solutions.

alexvoda 3y ago
You don't need to dig to make the diverter. You can also build upwards. And I don't think you even have to make it of concrete. But from the tiny (Electron) to the super heavy (Saturn, N1, SLS) they all used some form of diverter. It doesn't have to be over engineered like the ones built by NASA. Even the Relativity Terran 1 which only ever launched once had a diverter. Since the Super Heavy and the Starship are lifted into place by the tower instead of being rolled already assembled or rolled and erected from horizontal, it would be far easier for Super Heavy to have an above ground diverter compared to other rocket systems because it is no longer necessary to build the artificial hill and ramp on which to roll it. But the diverter is still needed.
- Gwypaas 3y ago
  > You don't need to dig to make the diverter. You can also build upwards. And wait years for the soil to settle.
  - alexvoda 3y ago
    You did not read the rest of the comment.

mhio 3y ago

Raptor vs water+steel https://www.youtube.com/watch?v=gPd6zYFLBqk https://www.youtube.com/watch?v=gPd6zYFLBqk

alexvoda 3y ago
That paragraph was hyperbolic sarcasm which I hoped would have been made clear by suggesting the tank would explode. Note that even in the test you linked the plate was angled. This is not done just to redirect heat but in order too redirect the sound: https://physics.byu.edu/docs/publication/4678 https://physics.byu.edu/docs/publication/4678 Reflecting that towards the engines is probably suboptimal.