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Everything posted by NathanKell
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Nope, it's not. However, wings provide more lift when you're going slower* (in relative terms) so stall speeds are quite low. *this is so that both gliders and spaceplanes "feel right" in their respective regimes.
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Jet Engine Thrust and Atmospheric Drag
NathanKell replied to Old Foxboy's topic in KSP1 Gameplay Questions and Tutorials
Check the atmCurve entries for jets. You'll find the decrease in thrust for decrease in density is not at all linear, indeed while all curves start at 1,1 (density is normalized to 1.0 = 1.225kg/m^3) up high the thrust multiplier at a given density may be 3x that normalized density or more. So jet thrust certainly does increase in relative terms, going higher. -
Tips: 1. Intakes have varying drag. Shock cones have the least (and are also heat resistant), but have less area than ramp intakes. The old 'scoop' radials have insane drag. The long radials have low drag, but not much area, so use lots. 2. Landing gear produce a fair amount of drag. Flip them so they're back first to lower it. Use the smallest gear you can (the old Small Gear Bay has much lower drag than the new gear because it's smaller). 3. There's still a bug with Mk3 cargo bays. Until there's an unofficial patch (or an official one, woo) be warned they cause a crapton of drag since they don't occlude the part attached behind them. 4. Wing area needed will vary since the Mk2 fuselage counts as a kinda-wing, so Mk1 or Mk3 planes need more wing area for decent AoA. 5. Climb to 10km, then dive to punch through the transonic, then climb again. If you have enough power to punch through the transonic on your way up then you're probably wasting mass on engines.
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Crossposted, it's Interesting Factoid Time! 1. There was absolutely no change in the atmosphere from 1.0 to 1.0.2. There was a considerable increase in dragcube (i.e. not wing) drag, but a slight decrease in wing drag. 2. 1.0's (and thus 1.0.2's) atmosphere is thicker than .90's, and so to compare drag at a given place between .90 (presumably with FAR) and 1.0.2, you need to compare density altitudes. 0.5kg/m^3 occurs around 14km in 1.0 (and thus 1.0.2). Note: In FAR, set density to ABS mode, it starts in REL mode. 3. 1.0 had much, much less drag than FAR (on .90) did. Terminal velocity for the Mk1 pod was ~100m/s in FAR in .90 near sea level, and 170+m/s in 1.0. Up high, say at density-altitude 0.1kg/m^3, you could get an extra 500m/s off the same thrust on the same craft. Delta V to orbit in FAR was about 3400, minimum, 3600 average; in 1.0 it was 2800 and 3300 respectively. 4. Even in 1.0.2, there's less drag up high. Top speed at 0.1kg/m^3 for the same craft with the same thrust is ~100m/s higher in 1.0.2 than in FAR-0.90. Down low, however, drag is much higher in 1.0.2 than in FAR. I encourage people to stop speculating and stop going off perception and to actually test stuff.
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Interesting factoid time! 1. There was absolutely no change in the atmosphere from 1.0 to 1.0.2. There was a considerable increase in dragcube (i.e. not wing) drag, but a slight decrease in wing drag. 2. 1.0's (and thus 1.0.2's) atmosphere is thicker than .90's, and so to compare drag at a given place between .90 (presumably with FAR) and 1.0.2, you need to compare density altitudes. 0.5kg/m^3 occurs around 14km in 1.0 (and thus 1.0.2). 3. 1.0 had much, much less drag than FAR (on .90) did. Terminal velocity for the Mk1 pod was ~100m/s in FAR in .90 near sea level, and 170+m/s in 1.0. Up high, say at density-altitude 0.1kg/m^3, you could get an extra 500m/s off the same thrust on the same craft. Delta V to orbit in FAR was about 3400, minimum, 3600 average; in 1.0 it was 2800 and 3300 respectively. 4. Even in 1.0.2, there's less drag up high. Top speed at 0.1kg/m^3 for the same craft with the same thrust is ~100m/s higher in 1.0.2 than in FAR-0.90. Down low, however, drag is much higher in 1.0.2 than in FAR. For rockets, that about evens out in terms of delta V to orbit costs. I encourage people to stop speculating and stop going off perception and to actually test stuff.
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[1.0.5] Advanced Jet Engine v2.6.1 - Feb 1
NathanKell replied to camlost's topic in KSP1 Mod Releases
So long as you derive from ModuleEnginesFX, engineering plugins should be fine, as should MultiModeEngine. -
So for everyone thinking 1.0.2 is too soupy, while down low things are draggier than FAR, over 14km (aka when density <= 0.1kg/m^3) I get _higher_ top speeds in 1.0.2 stock than I do in 0.90 FAR (same craft, rocket engine, checked to make sure thrust at that altitude was identical between .90 and 1.0).
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Please do NOT rush 1.1!
NathanKell replied to AbhChallenger's topic in KSP1 Suggestions & Development Discussion
sp1989: And I assume you've compared maximum speeds of a given craft in .90 with FAR, with speeds in 1.0.2? (note: jets don't count, since they were totally reworked. Compare rocket-powered planes, say, and falling capsules, and...) -
Can I/we get a full changelog for 1.0.1 and 1.0.2?
NathanKell replied to Franklin's topic in KSP1 Discussion
By digging, it appears the changelog missed that solar panels now have a temperature efficiency curve as well. I presume this means that hot solar panels don't provide as much charge per solar flux. -
Funny you should mention that; the turboramjet (note: turboramjet) engine does appear to be modeled on an "only moreso" version of that engine, i.e. one that switches over much more heavily to ram mode at high speed (rather than only bleeding some of the air around the turbine, on the Blackbird's J58). It's worth mentioning that, indeed, the jets are very, very OP compared to real life engines. The Blackbird's J58, that engine which topped out somewhere around Mach 3.5 (we presume), produced only 150kN static thrust (compared to the TRJ's 180) on 2.7 tons (compared to the TRJ's 1.8 tons). And the TRJ can provide useful thrust past Mach 4. Besides, the J58 was about 1.4 meters in diameter, not 1.25m. Oh yeah, and the TRJ is about 10x the efficiency (Isp) of the real engine. Now some of that is presumably because we can't make planes as well-streamlined as the Blackbird. But let's recall that the Blackbird had about 60 tons takeoff weight, on 2 J58s (300kN static thrust afterburning, total). Scaled, that's like using only two TRJs for a 72 ton craft. Try that. Please try that.
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What happened to the parts Drag readout?
NathanKell replied to TokiTech's topic in KSP1 Gameplay Questions and Tutorials
That drag value was for old aero. It now being utterly meaningless, it was removed in 1.0.1. Drag is dependent on orientation and mach number (and if any parts are occluding the part) so you can't boil it down to one number. If you want a per-part drag display, in flight go to the debug menu and then physics->drag and turn on "show drag data" and it will appear in part right-click menus. -
Fairing, I need help
NathanKell replied to Lohan2008's topic in KSP1 Gameplay Questions and Tutorials
You're not using a stock fairing part. -
Hah, didn't even realize I used your other name in the cfg. And you're most welcome.
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[1.3.1] Ferram Aerospace Research: v0.15.9.1 "Liepmann" 4/2/18
NathanKell replied to ferram4's topic in KSP1 Mod Releases
What AeroGUI will not give you, however, is any kind of stability determination in the editor; recall that in stock CoL is computed only for wings, and does not take drag into account (i.e. is not CoP). That means that you have literally no way of knowing (aside from personal expertise) whether your wingless rocket is stable, or whether a plane with lots of draggy parts and few wings is. :\- 14,073 replies
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Mass-optimal engine type vs delta-V, payload, and min TWR
NathanKell replied to tavert's topic in KSP1 Tools and Applications
Tangents aren't given for atmocurve curves for stock engines in 1.0.x. -
Liquid engines don't maintain power
NathanKell replied to geo950's topic in KSP1 Gameplay Questions and Tutorials
Got joysticks connected? Did you configure them? If not, do you press shift or control any? (or anything else to change throttle) -
Oh, stalls are simulated some. Check out the lift curve in Physics.cfg. Note how it has a definite peak around 30 degrees (0.5) and then falls off.
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Liquid engines don't maintain power
NathanKell replied to geo950's topic in KSP1 Gameplay Questions and Tutorials
Does your throttle display (on the left of the navball) waver too? -
Why do you think there's 31% less lift? Old lift: liftMultiplier = 0.038 New lift: liftMultiplier = 0.055 44.7% more lift.
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Great New Physics Thread!
NathanKell replied to AmpsterMan's topic in KSP1 Gameplay Questions and Tutorials
...Amps... Fixed. Thanks.