Nao

Welp i did something similar in version 0.16 Used every stock part available once (including only one strut lol), unfortunately it was too heavy to lift into stable orbit (not enough fuel tank parts), highest Ap was 221km. Cheers!

The “wings and wing parts†only create lift when they are angled in respect to current velocity vector. (have non zero angle of attack). What SPH shows in your example is direction vector with zero lift value. If you want to find how it will affect the plane in flight try picking up the base part (command pod or something) and rotate it with shift around. Also if you don't want your ship to flip under yaw, try putting base of the wing closer to the centerline or use two wings that are angled toward CoM like they are on SR-71 Blackbird.

Haha i think i used it that way right from the moment we got fuel lines stock. It felt natural somehow.

It was off for every launch. I don't fully understand how it works but i tested one launch with it and it took 32m/s more Dv with it to achieve orbit for the best profile and 25m/s more for "go to" one (without acceleration limit). I did some more runs trying to improve performance with CS on but the best i got was only... (edit): 4393 Dv with 5/45/7/66,6/23 setup. I see now that the CS really likes to clinch to the turn end altitude (and probably whole launch path) so when its low it wastes some fuel going excessively downwards. (can be counteracted with path angle as there is good old hardcoded -10deg as maximum downward attitude, with +7 from shape like in above example it maxes out on -3deg). I remember such problems with early mechjeb . It would probably work well with high Turn Ends but that wastes Oberth effect, so for me launching without CS is the way to go.

FAR feels quite nicely, more realistic, when flying standard rockets but if you have a good setup for frontal area, then you can achieve orbit using only ~3100-3200m/s Dv on pretty powerful engines, and Mainsail happens to be almost always the best option, with LV-T30 coming close second. I think with the density of the air drops too quickly with FAR, if the atmosphere spanned to 120-150km with little stronger drag effects at sea level it would end up being great. Also more updates on Mechjeb to orbit stock front. Using stock Kerbal X i've run a series of 50 tests. Each launch was up to 100x100 orbit, every test was ran without terminal velocity limit as Kerbal X is nicely designed around that already. (I'm showing the more interesting ones only to save space). T start T End Angle shape acc lim Dv fuel left in capsule 5 40 0 75 4399 637 - my personal go to model for most rockets 6 40 0 75 23 4379 644 - giving acceleration limit on my "go to" profile resulted in -20m/s Dv, (the KerbX has more thrust than my standard rockets) 3 35 0 100 4403 635 - most efficient i found for 100% shape, also includes turn start alt of 3km 6 40 -5 75 4400 636 - best one including negative angle, (small sample) 7 45 0 50 23 4397 637 - smallest Dv found for 50% shape, (small sample) 8 35 5 66,6 23 4376 645 - smallest turn end (efficiency dropped hard below 35km) 8 37 5 66,6 22 4375 645 - best profiles found. 7 40 3 66,6 23 4375 645 I feel like 66,6 - 75% shape is the sweet spot for many setups. The limit on acceleration for the Kerbal X was pretty big deal, as the mainsail was giving 5+ g's at burnout. Having shallower, slower ascent seemed to get the most out of Oberth effect. Positive turn end angle helped in keeping nose pointed as close to the velocity vector as possible. (Negative turn end angles can be good for ships that have less TWR in mid to late ascent - happens often with LV-N engines). I've included amount's of fuel left in capsule for comparison if somebody wants to try this without any mods with stock Kerbal X. If somebody has a profile that goes well below 4375m/s Dv to 100x100 orbit with KerbX please post the profile , as my test's had quite a lot of bias from my standard hand flown profiles. Cheers!

Agree 100%. Interesting byproduct of this is the fact that if we use turn end altitude that is in the atmosphere, getting to 100km orbit takes roughly the same Dv as getting to 70km. If we use the same turn end altitude inside atmosphere the 70x70 orbit flight will ascent much slower from it's turn end altitude and end up getting a lot more drag losses. So the higher the target orbit altitude is the more of the Oberth effect we can use (by lowering the turn end) and thus the net Dv does not change much. Personally I've found that 40-50 km is best for turn end on standard rockets. Also its kind of funny that with ferram aerospace mod, the best launch profile (lowest fuel consumption and launch mass) i got is by finishing burn at only 22-27km with turn start almost at launchpad and having TWR of 3-4. edit: I would say the opposite, any target orbit above 70km is best done inside the atmosphere (at around 40-50km) so that we get an orbit for example 100km x 10km while still at an 50km altitude, so that circularization at Ap will take only ~50-70m/s Dv

Nabs... 8209m/s, and if i can't have the whole thing disintegrate, i have 7877m/s with everything intact. (Third image at liftoff showing that the "plane" lifted off the runway on his own while moving horizontally) Done using 12 small control surfaces Thanks Cranium for showing the [imgur] tag

I think even symmetrical wing uses the Bernoulli's effect as the air splits below the wing nose, and travels longer distance above the wing. Also on topic of zero aoa. This type of airfoil can generate half of its lift at 0 aoa, and is used on commercial airliners to fight the wave drag at speeds close to 1mach.

We need to find space mermaids and get the merbone/mersoap/merwhatnot industry going! (a reference thread: http://www.bay12forums.com/smf/index.php?topic=25967.0)

Haha, just noticed that i misread your post, in polish we call slats - "spoilery" That's why I remembered about them and brought that CFD picture. For me the inverted flight works quite similar to standard when we try using Bernoulli's principle. It's just that the air takes "longer path" around the upper side even if the wing is flat there, because of where it splits at higher AoA (kind of like in my CFD picture). And that venturi effect you also mentioned really feels like right on spot. Also looks like foilsim is working again http://www.grc.nasa.gov/WWW/k-12/airplane/foil2.html. It works in browser and can simulate variety of airfoils. Quite fun learning tool.

ROTFL hahaha We have a winner! Jet to orbit right there! On topic of of exploits, recently i tried decoupling of the cockpit while descending from orbit-hop, it kind of worked as i managed to get from 2331 (maximum for the test craft) to 2335 m/s on a free-fall. I think with enough intakes (that allow for higher apopsis) It would be possible to go above Pbhead's record... at least until he creates his jet powered orbital trebuchet.

On the subject of spoilers ... This is a model that I've done on my CFD class (it's not a turbulent flow because it would take hours to compute on standard PC's) but it shows how the air actually flows. My CFD picture is kind off crappy ... I would be able to better demonstrate it if not the damn nasa blocking their browser based "foil sim" application >_<. As you can see the blue air - that goes under the wing is deflected downward, but after the end of the wing, due to interaction with the air that goes above, it stops it's flow downward. That shows that the top side of the flow has similar amount of energy as the bottom one (to be able to stop it's flow downward). So even at such high angles of attack the low pressure effect above the wing is comparable in strength to the mechanical deflection of air at the bottom. For lower AoA's the low pressure above the wing has even bigger effect in generating lift. The air that flow downwards after the plane passes it is actually mostly the one that was above the wing, not below. There is a problem with Bernoulli's law application here because, while it looks like it applies, it doesn't really. As the low pressure area above the wing is created mostly because of laminarity of the flow. As the air goes up first then goes down as it sweeps the wing - and the fact that it goes down creates low pressure area. As the wing moves away, there is a significant volume of air that were above the wing that is going downwards. If we loose laminarity of the flow above the wing there is not only an increase in drag, but a significant loss of lift due to turbulent air that doesn't want to move downwards and create low pressure area above the wing. Look for example at how "big" the speed brakes on a gliders are: They don't really create much drag, (speed decrease is almost non visible) what they do is kill laminar flow over the top of the wing that significantly lowers lift, and that requires the pilot to pull up the nose so that the whole wing generates more lift and drag. (I'm actually a glider pilot, and i can tell you first hand that during landing you just keep nose steady - to keep speed constant, and control the descent rate by operating the brakes, that's how important the flow above the wing is). And there is also the moment of stall. Even at high AoA lift still comes from air passing above, and stall creates a huge mess there that kills lift, that makes plane go down like a brick. The conclusion here would be that, most lift comes from air passing above the wing, but not because of Bernoulli's effect but rather the way wing is shaped, having a downwards sweep at the top. Also another obligatory B52 picture! (i love how they land almost nose down) http://files.air-attack.com/MIL/b52/b52_andersen_2.jpg (picture is too big to post without spoilers )

Bernoulli isn't the best way to describe airfoils, but so is the hand argument. Airliners have nose up attitude because they use fuselage to generate additional lift, also you can't really compare a flow of standard wing to an airliner which flies right on the boundary of supersonic flight which is quite different animal to standard model and the fact that the range of speeds the wing needs to be working is quite big. I would say that now days airfoils are as important as ever, just look at the complex mechanization in the wings of modern airliners. The power is there of course but civilian transport is and it always will be about efficiency, and you can't have that while powering through air on a board (except maybe in Russian engineering ) The wing deflection matters yes but so is the fact that most low to medium speed airfoils at 3-6deg aoa have almost no change in pressure at the bottom and have quite big one at the top. Another important thing is the laminar flow. That's what really differentiates wings from boards. Board or hand can generate lift almost purely from air deflection at bottom side, and the air on the top side is turbulent creating lots of drag. Wing on the other hand has (ideally) a laminar (non-turbulent) flow over the top, not only does this reduce drag by a lot. It also makes the air "glue" to the wing as it goes downwards on the top side, inviting more air above the wing to move downward. Also i wouldn't say that wings generate low amounts of lift at 0deg AoA. They work best at 3-6 (mostly) but if you going faster, they can provide plenty of lift at even negative angles. (for example competition gliders, that have to use negative flaps to reduce lift while cursing). rdfox, If you have any sources about "the primary sources of lift" of an wing, please share. As it does not sound right.

I have encountered this problem from time to time when doing symmetry (with and without Ed tools), and i play 99% stock game. I have no idea what actually causes it except it happens only for larger rockets. These glitches/bugs are pain but just because they are in the game i wouldn't say the parts are like a paper. They already feel really strong for me.

Ive done something similar, it kind of works, one important thing if you want to extract lift from rotating wings is that the force of lift is calculated from and acts at the base of the wing not in the middle. Also if it ends up being unstable, use struts, as small bending induces wobble that leads to more wobble and destabilization. Oh and if you put control surfaces at the ends remember that it works like in a helicopter - controls moved by 90degrees - that can create a illusion of instability when its just control mismatch between command pod and rotating wings.

Lol the game itself is "32", i also have seen no performance change between for example XP32bit and Win764bit on the same machine. Agreed that people will always go up to the limit. The problem is that there is really big difference between different users limits. And im not talking about somebody trying to run this game on a notebook. I have C2Duo too, even OC'd by 33% but for me lag starts sometimes way to early. Possibly its a driver or OS issue, but i tried many different things and it still not smooth where it should be. (I'm on W764 with all the CPU intensive stuff disabled, GTS450) I honestly believe that half of the FPS problems are caused because of bad optimization. I've launched 800+ part ships into orbit with ~10 fps but at the same time the game starts lagging with ships below 150 parts that have a lot of lights, ladders or solar panels. There also problems with debris near the launch pad, that sometimes create heavy lag even on low part counts. Scrapping the engine now would be an overkill for a small studio like SQUAD but i think there is still a lot to optimize at least for some people. Also the game is still in Alpha so this kind of problems are understandable from design standpoint, but it would be nice to get some more updates .

Short answer: yes Although parts have rotational drag in atmosphere as well as some limits on rotational speeds in vacuum to prevent physics from exploding. So it might be hard to make something spin super fast.

Wo ho, Great work Pbhead! The decoupling probably didn't make a big difference i think, testing it earlier as a propulsion method it didn't get me anywhere. You beat my manned attempt by 5 and unmanned by 1m/s (in earlier thread) now its my turn finally to get on the dawning board and get some ideas going.

It's true that wings create lift by forcing air downwards, but the main reason air starts to flow downwards is because of pressure difference and not because wing is physically deflecting them downwards. For example with this basic experiment, there is no direct force of moving air on the paper, it rises due to lower pressure of moving air above it. Also about the wing inclination, even the best wing profiles provide biggest L/D at small positive angles of attack. (around 4-6 deg) (L/D - lift to drag ratio, the plane flies most efficient at its maximum L/D) so most planes have some positive wing inclination.

Not a direct one, but asparagus takes somewhat more parts, brings less mass to orbit than SSTO, and can create derbies in orbit, all detracting from final score.

Uhh sorry i failed at reading comprehension, RL distracted me while reading your post and somehow after i returned i thought that you managed to get it working with KAS, and proceeded with my rambling. System restores are indeed pain to deal with. Hope you will have more luck with your next save! One more thing about that "hose" extension system is that it also worked quite well without the fancy wheels/plates at the end and with 1 docking port instead of 4. Just the presence of couple meters of bendable part made it easier to combine at not perfect angles. (the height difference being a problem still). I will definitely use it next time i build something, it would be autonomous tug like system too. Sorry again, and good luck.

A multiple design "BOOSTED FUEL DEPOT" challenge! Launch the most basic fuel tank: FL-T400 into orbit above 100x100km. Then using previous design *without removing* any parts, launch twice the amount of fuel into the same orbit. (bonus objective if you guys are confident in docking, would be to dock them together creating a fuel depot) Repeat until time runs out, the most fuel in orbit wins. note: as the FL-T400 holds 2 tons of liquid fuel and oxidizer, launches wold go like this: 2,4,8,16,32,64 [t]... 5th launch would need to get equivalent of whole orange fuel tank (32t of fuel) into orbit. It should be fun seeing design grow and create problems that can't be easily fixed.

Great that you made it. Since i did the test's of the hose system and it works really nice, ill post them here . My "sure fit" attachment system. Tested under severe stress of fully loaded orange tank with kerbin gravity. Because after connecting the craft automatically straightens out pictures were made just before successful docking. The last image shows how much not in line was the connection, as forces after docking throw the orange tank in the air. wrong approach angle wrong height (by more than half docking port) mixed angles and height JUMP The 4 wheels make sure docking ports are in line, and four docking ports twist the connection so that port planes match.

Seeing B-52 on final approach always gets me as the wings point upwards while nose point downwards (B52 has quite bit of wing inclination) ... and then there is F-8 crusader also haha. But there are planes with symmetrical wings like in KSP. They require nose up flight to generate lift. Extra 300 is a nice example. It's pure KSP design: a brick, pair of boards, powerful engine and a madman inside.

I go a step further and go with 30 deg inclination There are around 200-300 small delta winglets (part with best lift/mass ratio) hidden inside the hitchhiker pods all at 30 deg inclination. It flies quite realistic for a KSP physics Btw as we increase inclination wings provide more lift until around 30deg and then lift starts to go down. On the other hand control surfaces increase lift until close to 90deg (with a plateau at 30-35deg).