Where have you seen graphs claiming the ISP is significantly better than what REL says it is? Based on what?
Maybe a SABRE 3/4 cycle difference perhaps?
I'm not sure if this has been posted before.
That graph show significantly lower ISP than the 4000-9000 promised for the SABRE 4 in the Skylon Users Manual, and I too remember the curve being above the ramjet line. I hope it is just a badly drawn graph - but it may be a a result of the work done for REL by Bayern-Chemie on intakes and ramjets.
Quote from: john smith 19 on 01/04/2018 08:25 amI'm not sure if this has been posted before.Nice find, I've not seen it before. The part I found particularly encouraging is that they have managed to recreate the manufacturing process for the skin.
Quote from: JCRM on 01/09/2018 01:54 pmThat graph show significantly lower ISP than the 4000-9000 promised for the SABRE 4 in the Skylon Users Manual, and I too remember the curve being above the ramjet line. I hope it is just a badly drawn graph - but it may be a a result of the work done for REL by Bayern-Chemie on intakes and ramjets.Well "ramjets" in the context of the graph will be other ramjets used on other vehicles, usually for missiles like BOMARC, Bloodhound or Thunderbird, not the "spill ramjets" on SABRE.
IIRC when Mark Hempsell was working for REL he posted they were well within the SoA and contributed (indirectly) around 300-400m/s
I think the fact it was for the "Friends of Imperial College" may explain why they went into more detail than usual on their efforts to recreate the HOTOL skin material. That seems to have been one of the successful parts of the project. In one of his lectures Alan Bond mentions it seems to be nearly perfect for making spaceplane skins.
Does anyone know why the cooling rate has apparently reduced from one one-hundredth of a second to one one-twentieth?Graph I alluded to can be seen (not very clearly) at min. 28 of the following presentation:
The frame is up! #TF2
Great Progress at #TF1 @WestcottVP #SABRE http://bit.ly/2AHyhPI
https://twitter.com/ReactionEngines/status/961962101295210497
Quote from: FutureSpaceTourist on 02/09/2018 01:01 pmhttps://twitter.com/ReactionEngines/status/961962101295210497It certainly looks like things are moving. This is the assembly building for the test site and it looks close to weather tight, which should allow them to begin fit out. It would be exciting to think they could begin assembly of the first stage of the SABRE test engine before the test stand/control building is complete.
With recent SpaceX's successes and competition from BO, I think either Skylon is scaled up for larger payloads or this whole program will not generate a space plane, it will be for military and perhaps civil aircrafts.