Closed Cycle Gas Core Engine Warp/NonWarp ISP inconsistent
chris9871 opened this issue ยท 12 comments
With a 'Closed Cycle Gas Core Engine' on a craft, monitoring with MechJeb, I noticed that the actual DeltaV applied to the ship per fuel was different in and out of warp. The factor may be x2, however I didn't verify this beyond a rough eyeballing of the numbers.
E.g. Applying a 8000 delta-v maneuver: Without warp (or using physics warp) took 16,000 delta-v of fuel. In warp took ~8000 delta-v of fuel.
The ship I tested with was a fairly light ship: Engine, 7x cdt2505, graphite radiators, probe core, reaction wheel, battery, antenna, and some science. Total weight 45t.
KSPIE 1.19.2
I notice that the CANDLE Traveling Wave Reactor Engine also uses a different amount of fuel than the ISP indicates, perhaps 1.6x. The ISP changes as the thrust changes, but not by anywhere near this factor. I wasn't able to check it's warp ISP because thrust was set to 0 when warping.
Interesting. When travelling at timewarp it applies some time dilation effects, but it shouldn't start to become significant unless going faster than reaching 0.01c.
I don't think this issue has much/anything to do with timewarp thrust It's the non-timewarp thrust that seems to be way off. But in this case I was well below relativistic speeds: tests were run accelerating out of Kerbin orbit.
Well it uses stock engine for normal time propulsion. Seems more likely mechjeb calculation is wrong.
It's possible mechjeb is getting it wrong. However the warp result is correct in mechjeb, and the non-warp result uses a lot more fuel, so something is still wrong outside mechjeb.
The same thing seems to apply to the Open Cycle Gas Core Rocket. When executing a node, it uses twice as much fuel outside warp as inside warp.
what about regular stock engines, does MechJeb register their fuel consumption correctly?
It does seem to. Also many of the kspie engines seem to work compatibly with Mechjeb: VASIMR (in and out of warp), Plasma Nossle, Thermal Turbojet, Attila (in and out of warp), Magneto (in and out of warp).
Noted by emiliofloris @ https://forum.kerbalspaceprogram.com/index.php?/topic/172026-131144-ksp-interstellar-extended-1193-support-thread/&do=findComment&comment=3410750 this may be caused by a discrepancy between fuel flow on the engine and out of the tanks.