Quote from: meekGee on 02/03/2019 09:54 amQuote from: thxbmp3 on 02/03/2019 04:20 amQuote from: Llian Rhydderch on 02/02/2019 03:03 pmQuote from: Jim on 02/01/2019 05:43 pmThis is how the SSME does it, no combustion products going into tanks. H2 doesn't need heating but methane might and so a heat exchanger like the LOX side could be employed.That is an awesomely well-done image, Jim, of how another historical launch vehicle design has handled the provision of autogenous pressurization gases for propellant tanks.Would anyone on this forum be willing to have a go at trying to schematicize a design in that fashion for what might work for Starship and/or Super Heavy?That would be an awesome way to debate the merits of various approaches, with reference to a particular draft version of a schematic, here in the forum.Sorry to stray a bit OT, but I had some questions re: the beautiful schematic Jim posted. Isn't SSME an FRSC engine? Why do each of the turbopumps have their own preburners? Also, do the green areas represent anything (e.g. physically isolated volumes/chambers) or are they just there to highlight the locations of the turbines and pumps?Wikipedia (where that image is also posted) says Full Flow.https://en.m.wikipedia.org/wiki/Space_Shuttle_main_engineI looked at that Wikipedia article meekGee, and am not finding the "Full Flow" claim. Searching for "full" or "flow" or "staged" don't seem to find any instance of even a statement to that effect, let alone a sourced statement to support the statement. Were you possibly looking at some other article than Space_Shuttle_main_engine?
Quote from: thxbmp3 on 02/03/2019 04:20 amQuote from: Llian Rhydderch on 02/02/2019 03:03 pmQuote from: Jim on 02/01/2019 05:43 pmThis is how the SSME does it, no combustion products going into tanks. H2 doesn't need heating but methane might and so a heat exchanger like the LOX side could be employed.That is an awesomely well-done image, Jim, of how another historical launch vehicle design has handled the provision of autogenous pressurization gases for propellant tanks.Would anyone on this forum be willing to have a go at trying to schematicize a design in that fashion for what might work for Starship and/or Super Heavy?That would be an awesome way to debate the merits of various approaches, with reference to a particular draft version of a schematic, here in the forum.Sorry to stray a bit OT, but I had some questions re: the beautiful schematic Jim posted. Isn't SSME an FRSC engine? Why do each of the turbopumps have their own preburners? Also, do the green areas represent anything (e.g. physically isolated volumes/chambers) or are they just there to highlight the locations of the turbines and pumps?Wikipedia (where that image is also posted) says Full Flow.https://en.m.wikipedia.org/wiki/Space_Shuttle_main_engine
Quote from: Llian Rhydderch on 02/02/2019 03:03 pmQuote from: Jim on 02/01/2019 05:43 pmThis is how the SSME does it, no combustion products going into tanks. H2 doesn't need heating but methane might and so a heat exchanger like the LOX side could be employed.That is an awesomely well-done image, Jim, of how another historical launch vehicle design has handled the provision of autogenous pressurization gases for propellant tanks.Would anyone on this forum be willing to have a go at trying to schematicize a design in that fashion for what might work for Starship and/or Super Heavy?That would be an awesome way to debate the merits of various approaches, with reference to a particular draft version of a schematic, here in the forum.Sorry to stray a bit OT, but I had some questions re: the beautiful schematic Jim posted. Isn't SSME an FRSC engine? Why do each of the turbopumps have their own preburners? Also, do the green areas represent anything (e.g. physically isolated volumes/chambers) or are they just there to highlight the locations of the turbines and pumps?
Quote from: Jim on 02/01/2019 05:43 pmThis is how the SSME does it, no combustion products going into tanks. H2 doesn't need heating but methane might and so a heat exchanger like the LOX side could be employed.That is an awesomely well-done image, Jim, of how another historical launch vehicle design has handled the provision of autogenous pressurization gases for propellant tanks.Would anyone on this forum be willing to have a go at trying to schematicize a design in that fashion for what might work for Starship and/or Super Heavy?That would be an awesome way to debate the merits of various approaches, with reference to a particular draft version of a schematic, here in the forum.
This is how the SSME does it, no combustion products going into tanks. H2 doesn't need heating but methane might and so a heat exchanger like the LOX side could be employed.
Don't get your information from wikipedia.
Modified Raptor schematic to add a heat exchanger in the methane pre-burner turbine exit flow. After adiabatic expansion pressurant gas was still too cold.John
Quote from: livingjw on 02/03/2019 04:49 pmModified Raptor schematic to add a heat exchanger in the methane pre-burner turbine exit flow. After adiabatic expansion pressurant gas was still too cold.JohnThanks for that mod, comparing it and the original and the SSME side by side by side is very instructive. The SSME with two stage pumps is a lot more complex...So I guess I was sort of half right about the possible need for a heat exchanger.
[snip]- The lack of boost pumps is puzzling. I think that the header tanks might be held at a higher pressure than the main tanks in order to start the engines without boost pumps.John
