Quote from: chopsticks on 05/20/2023 04:10 pmQuote from: DanClemmensen on 05/20/2023 03:47 pmThe deluge system will apparently be pressurized by high-pressure gas to a pressure of about 12 bar at the orifices. This is a "head" of about 400 feet. To get the equivalent using a water tower, you need a tower about 400 feet high positioned near the OLM.But wait! SpaceX already has a 400-ft tower near the OLM. Why not just just put a big water tank at the top? It should be cheaper to operate and probably cheaper to build than the gas pressurization system. You need the same amount of energy to pump the water as you need to compress the gas, but pumping water up to load the tank is almost certainly much cheaper and is logistically simpler. You probably need a pipe less than 1 m in diameter to do the deluge, and the bottom sections of that pipe must handle the entire 12 bar. A smaller pipe can be used to pump the water up, and pumping water up 400 feet is routine.How would you get said water tank up there?With a crane. That's how they got all the other stuff up there. If you don't want to rent the super-big Leibart, then erect a small hoist on the top of the tower. Use multiple smaller tanks as they are doing on the ground now. You can also build it in place. For future towers, plan a single larger tank as part of the initial build. Note that big water tanks are a well-understood technology. The bottom of a 33-foot tall tank on top of the tower is only at 2 bar, not at the 12 bar of the pressurized tanks on the ground.
Quote from: DanClemmensen on 05/20/2023 03:47 pmThe deluge system will apparently be pressurized by high-pressure gas to a pressure of about 12 bar at the orifices. This is a "head" of about 400 feet. To get the equivalent using a water tower, you need a tower about 400 feet high positioned near the OLM.But wait! SpaceX already has a 400-ft tower near the OLM. Why not just just put a big water tank at the top? It should be cheaper to operate and probably cheaper to build than the gas pressurization system. You need the same amount of energy to pump the water as you need to compress the gas, but pumping water up to load the tank is almost certainly much cheaper and is logistically simpler. You probably need a pipe less than 1 m in diameter to do the deluge, and the bottom sections of that pipe must handle the entire 12 bar. A smaller pipe can be used to pump the water up, and pumping water up 400 feet is routine.How would you get said water tank up there?
The deluge system will apparently be pressurized by high-pressure gas to a pressure of about 12 bar at the orifices. This is a "head" of about 400 feet. To get the equivalent using a water tower, you need a tower about 400 feet high positioned near the OLM.But wait! SpaceX already has a 400-ft tower near the OLM. Why not just just put a big water tank at the top? It should be cheaper to operate and probably cheaper to build than the gas pressurization system. You need the same amount of energy to pump the water as you need to compress the gas, but pumping water up to load the tank is almost certainly much cheaper and is logistically simpler. You probably need a pipe less than 1 m in diameter to do the deluge, and the bottom sections of that pipe must handle the entire 12 bar. A smaller pipe can be used to pump the water up, and pumping water up 400 feet is routine.
Quote from: CMac on 05/20/2023 03:07 pmThe colour temperature of the mist cloud around the steel plate, would that represent the temperature of the plate? Most of the light seems to be coming from the area where the white-out spot (saturated exposure) is.The mist colour temperature looks like about 900 to 1000 C.I'm not an expert, but I think the rocket exhaust bounces off the stagnation surface where the exhaust pressure matches the steam pressure. This is not the temperature of the plate.
The colour temperature of the mist cloud around the steel plate, would that represent the temperature of the plate? Most of the light seems to be coming from the area where the white-out spot (saturated exposure) is.The mist colour temperature looks like about 900 to 1000 C.
Quote from: DanClemmensen on 05/20/2023 03:28 pmQuote from: CMac on 05/20/2023 03:07 pmThe colour temperature of the mist cloud around the steel plate, would that represent the temperature of the plate? Most of the light seems to be coming from the area where the white-out spot (saturated exposure) is.The mist colour temperature looks like about 900 to 1000 C.I'm not an expert, but I think the rocket exhaust bounces off the stagnation surface where the exhaust pressure matches the steam pressure. This is not the temperature of the plate.Ok, that seems to be reasonable. Under high pressure, the steam has a high emissivity so it would be fairly opaque.I think that the colour of the clouds away from the exhaust will be close to the colour of the steam near(ish) the surface, e.g. 5 cm (wild guess). I don't think the combustion emissions are playing a large part in this colour since the colour stays fairly constant while the flame is quite variable in intensity.So at the stagnation front, a colour representing around 900 C (maybe a bit lower). Then that would represent an upper bound on the temperature of the plate. Plate temperature could be a lot cooler, given that there is probably a good flow of water/steam at the surface.Edit to add: just after the engine cut-off, as the water is seen starting to emerge from the plate, the surface of the plate has no glow at all. If there was a high temperature on the plate, you'd expect some afterglow, even if very brief.
Things are very fluid on the launch pad.Watch live: youtube.com/live/tS2PHJmvJ… #SpaceX #Starbase #Starship #superheavy
The WAG by forum members here is the plume pressure near the plate will be 12 bar. Water boils at 188 C at 12 bar. I think the plate will not exceed this temperature, but that most of the plume will be reflected from the stagnation surface without being cooled. A small part of the heat energy will create the steam and the rest will stay in the diverted plume.
Quote from: DanClemmensen on 05/22/2023 04:16 pmThe WAG by forum members here is the plume pressure near the plate will be 12 bar. Water boils at 188 C at 12 bar. I think the plate will not exceed this temperature, but that most of the plume will be reflected from the stagnation surface without being cooled. A small part of the heat energy will create the steam and the rest will stay in the diverted plume. WAG? In the UK that means "Wives and Girlfriends", usually associated with football players.
https://fox4kc.com/news/semis-haul-2-massive-tanks-through-kansas-city-area-impacting-traffic/Those are some big tanks!
https://twitter.com/elonmusk/status/1662263704262680577QuoteMajor launchpad upgrades should be complete in about a month, then another month of rocket testing on pad, then flight 2 of Starship
Major launchpad upgrades should be complete in about a month, then another month of rocket testing on pad, then flight 2 of Starship
so much work at Starbase. We have seen sheet piles being driven into the ground these will form a retaining wall that can then be excavated to work on the pipe for the water and install the steel watercooled plates
We spotted the new steel plates, what do you think these will be used for?We have a possible answer and render by @mcrs987 explaining these in our latest flyover update: youtu.be/3RPtBAET3Yw
