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Found 26 results

  1. Hi, im wondering wether i should put all the solar panels for the Magnetoplasmadynamic's needs. Im considering overcovering the spaceplane with flat solar panels or just the typical Gigantors XL Would the plane oversuffer from drag if i overcover it with the flat solar panels?
  2. So I'm making a spaceplace in the 50-60 ton range, and I don't know what I did, but some relatively minor change now causes it to no longer go to space. I can't figure out what happened, but I think something is causing massive drag that shouldn't be, as it now feels sluggish and underpowered, and this is compared to another fairly similar spaceplane that's 15 tons heavier, with the same engines, it it goes to space just fine. Even worse, I just now forgot to retract the landing gear, and it still outperformed the lighter plane. So something's very wrong. I've tried to figure out what's causing the drag, but no luck. I'm not even sure if it's really drag, but it seems to be the most likely culprit. So far, I haven't any way to even see drag values. Supposedly MechJeb shows atmospheric drag, but I can't find that feature. And some other mods I tried were out of date. At any rate, this will only confirm if drag is the issue, not what part is causing it. Any ideas? Any suggestions to see the drag of parts?
  3. I am playing KSP with a bunch of mods. the game was running fine and then i had a game crash. i had to re validate, update my drivers and restart my computer to be able to get KSP to load again. when it did finally load and i tried to launch a plane from my hangar but i was unable to lift off as my speed couldn't go above 13m/s. i know it was working before because i had no problem gaining speed and flying with the exact same plane i was using. i thought it could just be the liquid engines but when i loaded up my rocket fueled plane it had the same effect. i could not gain speed its as if the physics had been changed by a mod or something was affecting the atmosphere. i tried deleting my physics file and re validating but that didn't fix it either. i opened the console config with shift F12 or w/e it is and looked up the default values online and the numbers were the same? any ideas on what could be causing these physic issues? or mods that might tamper with physics? i dont have the real physics mod installed thanks
  4. I've always hated the way drag is shown in stock KSP. I have no idea which parts are causing the most drag, and by how much. All i get are a bunch of long red lines overlapping each other so they are impossible to distinguish from one another. Is there a mod that changes the way drag is shown in the aero forces overlay view? I'm looking for something stock compatible that's not going to actually change drag, but just show it easier. Thanks in advance!
  5. So, I'm not sure if anyone else has noticed this, but ladders have a ridiculous amount of drag. I've had them create as much drag as a Big-S Shuttle Wing on some occasions. Now, is there any nice way to make drag cubes check for other drag cubes existing in the same space, or would this be an absolute nightmare for anyone to code? I don't know a thing about modding on KSP, so I am posting this as a request, but if anyone knows some of the basics on how to do this, I'd be willing to try my hand at it.
  6. Hello, I was wondering if the parts that are radially attached inside the Mk1 Structural Fuselage are dragless and protected from reentry heat. I've noticed that with angle snap off, you can radially attach parts inside the fuselage, but when doing a reentry, things inside were showing temp gauges and some of them were destroyed. Do I need to use the fairings for that? Or was it that the fuselage was getting heated up(and resisting it fine) but passing that heat by conduction to the parts inside?
  7. It'll be really helpful to know the Lift&Drag characteristics on altitude and speed, to fly a proplane. Anyone knows something about this?
  8. With 1.2, drag is (even more) king and nosecones dictate that to a large degree. Since the Mk.3 Cockpit is the best command pod for reaction wheels, crew capacity, etc, I try to use it as often as possible. Thus: What nosecone is the least draggy while still being somewhat sane, functional, possibly even nice-looking? This is the best I could come up with: 1.25m Fairing clipped slightly into the Mk.3 pod. 2600 Max Temp (seems to be the highest of anything besides the pod itself)
  9. I have this spaceplane built in the previous versions, which doubles as a reasonable lander And it used to make it to orbit with plenty of dV to spare. I've just loaded it in 1.2.1 though and the rapiers can't keep up the thrust when they are breaking the sound barrier: They'll hold up to about match 1, but between match 1 and match 1.1 they will consistently keep loosing thrust, even if I level out or even descend slowly, which keeps me stuck below match 1.2. I've tried placing precoolers in front of the engines, but they don't change performance. I've replaced the front of the spaceplane with the MK2 (not inline) cockpit and while there is a thrust loss, it isn't nearly as pronounced and I can more easily break the sound barrier, so I guess the issue is related to the changes in drag. Am I right? (And it's a pity, because that's a nice position to put the docking port). I also installed Interstellar (and removed the rapiers MM patch as it caused them to overheat) but I don't think Interstellar should be the curprit
  10. What are the aerodynamic properties of this part? Does the big flat part cause drag if you put engines on it? Or does it count as a smooth mk3-to-3x1.25m adapter?
  11. So pretty much every lunar rocket I've been building in 1.2 has some variation of "small 2.5m tank, Terrier, decoupler, larger 2.5m tank." I had a general sense that I might be taking some kind of drag penalty for the change in form factor, but was not exactly sure how it worked or how large the effect was. So, following @Gaarst and @Yakuzi's excellent work on nose cone drag, I whipped up a little experiment. This was my rig: The nosecone, capsule (I edited mass down to 3 tons so I would actually use it in my new career) and top 2.5m fuel tank represent the payload, and will be providing the drag occlusion, if any. The middle piece was my independent variable. I tried four combinations: (1) Terrier alone, as shown here, (2) Terrier with 2.5m interstage fairing, (3) a 2.5m probe core instead of Terrier (selected because it is the same mass as the Terrier, but in the 2.5 form factor), and (4) the 2.5m probe core with 2.5m fairing base. On #4, I could not actually build a fairing, I just wanted to check the fairing base itself didn't cause weirdness. I also drained fuel from the upper tank to balance out the added weight of the fairing when it was used (within a couple kilograms, at least). Just to keep extra variables out, I also disabled the reaction wheel on the probe core when it was used. The bottom 2.5m tank and Reliant provided the thrust. On each test, I set the SAS to hold radial out, and fired the Reliant with only the bottom fuel tank available. I then saw how high each rocket would go after burning through the bottom tank. #1, the plain Terrier, only made it a little over 9,000 meters, #2, the Terrier with fairing, made it over 11,000 meters. #3, the probe core, made it over 13,000 meters! #4, the probe core with fairing base, ended up very close to #3. So the fairing base appears to have no special aerodynamic effects. Results: It looks like parts in front do not fully occlude trailing parts if there is a smaller-size part in between. The lower tank may be getting some drag occlusion, but definitely not as much as if the stack was uniformly 2.5m wide. So all else being equal, it's better to avoid the "hourglass" shape. Using an interstage fairing considerably improved drag, though surprisingly, the net effect was not as good as a pure 2.5m setup. Thus, besides their weight and cost, fairings don't appear to be a perfect option occlusion. It's also worth mentioning that, even when I did NOT reduce payload weight to compensate for the fairing, it still made the Terrier package go higher. This suggests that interstage fairings are probably a good idea, at least as long as the fairing base is staged low enough you're not hauling it to Tylo and back or something. In career mode, though, the fairing might or might not be worth the cost. One final note: this test did not attempt to measure drag occlusion when the rocket is not facing directly prograde. But I would expect the penalty for changing sizes to be even worse in that case, since there's not even perfect occlusion from a geometric standpoint. tl;dr: going back and forth between form factors is bad for drag. If you have to do it, consider an interstage fairing.
  12. Speaking about drag occlusion generated by different parts, are 3.75m parts occluded by Mk3 parts? Thank you. Cheers.
  13. A drag-reducing aerospike is a device (see Nose cone design) used to reduce the forebody pressure aerodynamic drag of blunt bodies at supersonic speeds. The aerospike creates a detached shock ahead of the body. Between the shock and the forebody a zone of recirculating flow occurs which acts like a more streamlined forebody profile, reducing the drag. Does the game take advantage of such things? I don't really understand how KSP aerodynamics work, but it should benefit from these kind of gadgets if it modeled airflow realistically, especially in mods like RSS where the atmosphere part of ascent is quite long.
  14. I'm creating scaled-up versions of the ROUND-8 Toroidal Fuel Tank, and need a hand with drag cubes. The stock part has a custom DRAG_CUBE defined as follows: // AREA DRAG COEFF DEPTH cube = Default, 0.2859113, 0.6272321, 0.6734665, // X+ FACE 0.2859113, 0.6268581, 0.9227022, // X- FACE 1.21, 0.96, 0.2872447, // Y+ FACE 1.21, 0.96, 0.245615, // Y- FACE 0.2958315, 0.6112254, 0.6440083, // Z+ FACE 0.2958315, 0.6160544, 1.104762, // Z- FACE 0, 0.02261333, -2.695719E-09, // BOUNDS CENTER 1.152236, 0.3307782, 1.135139 // BOUNDS EXTENTS // X Y Z In one case, I'm scaling the part by a factor of 2.2 along the X/Z axes, and 4.15 along Y axis. I'll also be moving the Y-coordinate of both attachment nodes up to 0.43 so the tank wraps nicely around the exhaust manifold of a Poodle engine when mounted above it (yes, there will unfortunately be a bit of clipping, but hopefully we don't need to get into that here). MODEL { model = Squad/Parts/FuelTank/fuelTankToroidal/model position = 0, 0, 0 scale = 2.2, 4.15, 2.2 } To visualize it, red is the stock part, and blue is my scaled up version (note some of the values may be approximate): I'm trying to figure out how I should adjust the drag cubes to sensibly represent the increased drag of the bigger part. I read the following links: Drag cubes introduced Explanation and "OMG" Experiments Image showing XYZ face orientation Drag cube scaler/calculator and its announcement But still have some basic questions on how they work: In general, how "tightly" should the values correlate to my part geometry? e.g. Should I be doing calculations based on the dimensions of my part? Or is the system just an imaginary way of visualizing multipliers which should be tweaked using best judgement? (Since drag cubes also affect buoyancy, I'm assuming they need to be fairly tightly coupled to part geometry, and if you start going willy-nillie to tailor the drag you'll end up with unwanted side effects in the water... unless you decouple the drag/buoyancy cubes via buoyancyUseCubeNamed) I infer AREA should roughly correspond to the surface area my part presents to the given face. Should it be calculated from a projection of my part onto that face (or maybe from an outline of the cross-section made at DEPTH)? e.g. The stock toroid projected onto the Y+ face (i.e. viewed from above) looks like this (numbers approximate): So the area is roughly 0.74m2 (or 1.04m2 if you ignore the hole in the middle). That's a bit smaller than the 1.21m2 area in the stock DRAG_CUBE above (I guess for whatever reason Squad used a slightly bigger outer diameter of 1.24m). But what I'm really wondering is why did they ignore the hole in the middle? Does that mean I won't get the benefit of reduced drag from the air rushing through the middle? (It's a valid question - I could build a craft where that hole isn't occluded) How does DEPTH work? Is it to tell the game something akin to where "tip" drag ends and "surface" drag begins? @NathanKell said it should be "depth of widest point from the frontmost point at that angle". I assume that means if you have, for example, a part that looks like a pencil pointing upward, then the DEPTH of the Y+ face should be equal to the length of the pencil's tapered tip, like so: The widest point of the stock toroid tank is at its equator. So I'd expect DEPTH for its Y+/Y- faces to be roughly half the height of the part - but they're both nearly the FULL height. Similarly, X-/Z- are only slightly less than the full outer diameter (while I'd expect them to be much smaller, about equal to the outer radius), and I'm totally confounded as to why they're so different from their X+ and Z+ counterparts. The mesh looks reasonably symmetrical. Does it have something to do with the little gauge dial on one side? If so, why's that bugger have such a big effect, and why doesn't the effect come into play when the wind's coming from the opposite direction? Any advice for determining the drag coefficient? Is it intended to be adjusted to represent the "pointiness" of my part in the given direction (and perhaps the "slipperiness" of the material composing its surface)? Do I have a fair bit of leeway to adjust it (without causing unintended side-effects e.g. to buoyancy)? What are the extents of the drag cubes (last tuple) used for? e.g. Does it come into play when the game compensates for occlusion of stacked parts? Any general guidelines would be helpful. e.g. At one point @NathanKell said that for "a stackmounted hollow part" like a cargo bay, the Y+ and Y- area values should be adjusted to match the non-hollow version of that part. That's a very easy-to-use piece of advice that seems to make sense intuitively :-). Another one was "If the part is not hollow in terms of mesh, but should be (in terms of it being an intake with a flat black section that's supposed to represent a hole), you play with the drag coefficient (second number in the triplet) in the intake's incoming axis." Although I'm wondering, could you not simply "fake" a hole in the drag cube (regardless of whether it's in the mesh) by subtracting the opening's area from the face it points toward (i.e. poke a hole like I want to do with the toroid above, but only for the face the intake faces)? Have the part-level tags dragModelType, maximum_drag, minimum_drag and angularDrag been deprecated?
  15. I hope I'm in the right place to post this, but I've noticed a major increase in the applied drag after the recent update. I did some testing in the current 1.1.2, 1.1.1 and 1.1 versions of the game and noticed that 1.1 had significantly less drag applied than subsequent ones. According to what I could conclude, 1.1.2 applies almost 20% more drag, which is never mentioned in any of the release notes. (1.1.2 just introduced some optimization). This practically grounded 90% of my spaceplanes, so I'm curious if anyone else noticed this? Here are some screenshots with flight data GUI for both 1.1 and 1.1.2. (notice that 1.0.5 aero was more similar to 1.1). Flight stats in 1.1 And the same situation in 1.1.2
  16. Hi, I'm a new poster but have been (trying to) play KSP for a long time now. After a lengthy break, I've picked it up again at v1.1.2 to discover quite a lot has changed. I had a program back in the day for modelling ascents of various ships into orbit and have been trying to update the code to model the new drag cube system. However, when opening my GameData\Squad\Parts folder, none of the .cfg files for any of the parts seem to have the DRAG_CUBE { cube= } parameters as described in numerous discussions on the new aerodynamics system (see link) Am I missing the most recent files, or am I simply looking in the wrong place? Any help is much appreciated, Cheers
  17. Is there a mod that adds orbital decay effects by : Atmospheric drag, Tidal forces...? like this : https://en.wikipedia.org/wiki/Orbital_decay
  18. In flight, you can open up a nice aero forces display by opening the ALT F12 debug menu, going to the physics tab, then the aerodynamics sub-tab, then checking the "display aero data gui" checkbox. I've noticed however, that the lift:drag ratio numbers seem very poor compared with real-life airplanes. The best I can get is 8 or 9 to one, at 2 degrees AoA, at low speed and altitude. At 0.82 mach and 10km, similar to how commercial airliners fly, best seems to be 2.8 AoA and maybe 5 to one lift / drag ratio. Real commercial airliners are pushing 20:1 at such a point, in fact i'd bet the newest of them, the 787, is over 20 at an "economy cruise" setting. Supersonic , things get worse. At 1.3 Mach, I try climbing higher to use thinner air to compensate for the extra drag. Best results seem to occur at 3.5 AoA and altitudes of 14km or more, I might get close to 4:1. Concorde did 7.5 to 1 at mach 2 and 60,000ft. As we get deeper into the supersonic regime, numbers ebb steadily lower. Above 20km I'll start my final climb to orbit at something like Mach 4 and shutdown engines (needing only to circularise) at Mach 6.6. During this period optimal AoA seems to shift from 4 degrees to 8 or so. At best, I might see L/D display of 2.8, whilst pitching up to high alpha because my craft is overheating can pull it down to 1.6. Reading a little further on wiki, it appears max lift:drag does taper off with increasing mach no matter how high the altitude and thin the air, especially for conventional supersonic/transonic swept designs. However waveriders that rely on compression lift can do better, with designs like the Hypersoar project making 10:1 at mach 6. I guess this is all to compensate for the overpowered nature of jet engines themselves, compared with real life. I still find it a bit weird however, that if my L/D is so poor, why my spaceplanes are so reluctant to actually land. I've long since given up targeting the runway and am quite happy to settle for anywhere on the KSP peninsula or in the shallow seas nearby, usually after flying back and forth across it several times. I guess as we head below 100 m/s our L/D is getting up that of a Cessna light aircraft and we're usually coming in a tad "hot" , also the drag from landing gear, flaps, and jet intakes (with engines off!) is less than it should be .
  19. I am trying to build my first lander to get to Duna and this is what I got: My issue is that empty space for the small sized engine under the fuel tank. I am assuming this will cause a good deal of Aero-drag, but upgrading from a Terrier to a Poodle costs me like 600 Dv that I don't want to lose if I don't have to. Any ideas? I ask because I am sure this will come up again in the future
  20. So, I'm back after a long hiatus and v1.0 and all that good stuff. I'm trying career mode and I am getting burned (pun intended) on the new aerodynamic and heat effects. I am trying to do a test contract for the RT-10 booster firing between 40km and 45km and a certain speed window, I did this by stacking three RT-10s with tweaked thrust limiters so the third one ignites while coasting in the target window. Contract satisfied, but then I can't get the capsule safely to splash down because the chutes keep failing. I've tried deploying them as early as possible but it seems like nothing I do will get them to open until 5km altitude and by the time my capsule + heatshield is that low, it's screaming along at nearly 1km/sec and the chutes tear right off. I'm not sure how to slow my capsule down enough to use the chutes safely without being able to deploy them earlier. Thoughts? Thanks!
  21. You play with low resolution? You have heavily modded KSP? You often hit the wrong button during EVA because part's menu is constantly moving? You often get in trouble in the most inappropriate moment when you right-click on part but most portion of its menu hides off-screen so you have to zoom out and rotate camera to actually see it's bottom and all of buttons? If yes then worry no more because Troiden Industries are proud to present you DraggableMenu. With this small mod you won't ever have such problems. Features: Automatically rises menu if it gets off-screen. Freezes menu position when mouse is over it. Allows you to move any menu around your screen by Alt+Click, both in Flight and Editor. How to move menu: Press your ModifierKey(Alt by default) and drag the menu anywhere on your screen and it will stay there(regardless of what buttons you press after) until you close it. Then you can close it the same way you usually close any other menu: either by right-clicking(without Alt pressed) on any part or by right-clicking on empty space between your ship and other windows. This mod is based on famous lifesaving MenuStabilizer written by comrade Alexander Gavrilov aka @a.g. and includes all of its features. Compatibility: It is not recommended to install both MenuStabilizer and DraggableMenu because they will fight for control of same things what can lead to fitful menu movements. Download: SpaceDock Curse GitHub //Coming soon. Installation: Extract the .zip into your KSP directory and overwrite if asked. License: MIT Changelog: Feel free to post your comments, suggestions and of couse bug reports, but don't forget to include your KSP.log.
  22. I know this question has been asked time and again, but I have dug deep and yet to find a clear cut answer to the question: Are pre-coolers capped with an aerodynamic nose (advanced nose or tail connector) less draggy than the same amount of shock cones per intake area? That seems to be the two greatest issues is intake area vs drag on any high speed vehicle. Testing the same vehicle with the same weight, does intake area even count towards drag on the pre-coolers that are streamlined? I guess what I'm asking is how the heck drag is calculated, especially if you can't directly tell from the debug part menu? This is the single most difficult issue preventing an SSTO to the outer planets is the drag on Kerbin.
  23. (I think this is a general question and not particularly related to any specific craft - but if a specific example would be useful then I can upload one later.) I recall reading that attaching items radially are affected by drag, and that items attached in a stack are not. What happens if you attach an RCS thruster behind a wing (where you would usually attach control surfaces)? Is that radial or stacked, and (more importantly) is it affected by drag? I think that I also recall reading that it doesn't matter how it has been offset and rotated, the item still behaves the same as if it were not offset or rotated. I assume that this means that I can make a RCS thruster look like it is attached on the body just behind the wing, when it is actually attached to the wing just next to the body? Final questing: do RCS thrusters work inside cargo bays? IRL that would not work, but I wonder if the game engine is simplified enough to get away with it.
  24. As part of some nose cone testing (put nose cone on a Hammer SRB with minimal control surfaces and ballast to even out weight differences and see how high they go) I noticed that a shock cone appears to have the same drag regardless of being open or closed (the test vehicle reaches the same height). Has anyone else observed this or is there something screwy with my test? Thanks, Richard
  25. Hello, I have been performing some simple nose cone drag test measurements (affix nose cone to test vehicle, ballast out mass differences, launch and see what peak altitude is achieved). Although this has been successful for a simple part like a nose cone it is labour intensive, very sensitive to part mass (a different mass means different accelerations are caused and different speeds obtained) and positive feedback (less drag => more acceleration => higher speed => get to higher altitudes quicker => increased engine thrust => higher speed .......) and isn't a direct measure. Is there a better way to get quantitative drag vs speed information? The unrealistic ideal would be a set of drag (and lift for relevant parts) vs speed curves as functions of altitude and angle of incidence (but that would probably be far too complex to measure/calculate) Thanks for any suggestions, Richard