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Levelord

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Everything posted by Levelord

  1. I have some design recommendations for you if you'd like You may want to remove the Default Structural Intake, it has a drag coefficient of 0.9507048. Compared to the Shock Cone's drag coefficient of 0.3. A single structural intake generates more than 3 times the drag as a shock cone. With your craft having 4 of them, it's generating 12 times more drag. 2 Shock cones are adequate enough for your RAPIERs to bring the craft into orbit. Also consider changing the Default Clamp-O-Tron Docking Port (Drag coefficient 0.91494) For a Clamp-O-Tron Shielded Docking Port (Drag coefficient 0.8379832). Or better yet, an inline docking port since it benefits from avoiding drag and comes with in built RCS fuel too. It might also be beneficial to only have 1 probe core instead of 2 to save on weight.
  2. I don't exactly like it, but it doesn't stop me from mastering it anyway.
  3. These have been tested to improve aerodynamic flow of the aircraft and significantly improves dV performance: These are some tests and data mined drag values: Small Nose Cone Frontal Area: 0.3032565 Drag Coefficient: 0.401173 Small Nosecone is attached to aft connection point of RAPIER engine Firing the engines up. Nosecone does not overheat and does not obstruct thrust from the engine. RAPIER with rear nosecone has a performance increase over the other with no rear nosecone. Conclusion: Rear nosecones help improve aerodynamic performance by reducing rear drag. Nosecones are recommended for all exposed rear ends of aircraft. (Especially for those with exposed attachment points.) Shock Cone intake Frontal Area: 1.213026 Drag Coefficient: 0.3 VS. Advanced Nose Cone - Type A Frontal Area: 1.213026 Drag Coefficient: 0.3476872 //Has 0.0476872 more drag than Shock Cone Intake. Left is the Shock Cone, right is the Type A Spooling up engines for launch Shock Cone beats the Type A by a mile. Conclusion: Other tests not shown, but have been tested with other nosecones. Tested against Aerodynamic Nosecone, Advanced Nosecone - Type B, Tail Connectors Type A/B and various other intakes. The Shock Cone outperforms all other nosecones, outcome is the same being opened or closed to collecting air. Shock Cones are recommended for all leading edges of SSTOs, planes and rockets to minimize drag as much as possible regardless of air breathing engine use. I've compiled all the knowledge I've gained from extensive testing of the aerodynamics systems to come up with a mere 16-tonne SSTM (Single Stage to Mun) craft that carries 4 Kerbals. It's from the knowledge to reduce struts to avoid drag, shock nose cones being the very best nose cone to reduce drag (it has the lowest drag coefficient of any nose cone and also has the lowest weight), smaller cones on the RAPIER engines to which I will trademark with the name RAPIERSPIKE engine. Over 1000m dV at a 76km orbit. Shock Cones are used to reduce drag an all leading edges of the craft. Minimal strut usage; Only 3 struts in total holding craft together. Craft is deliberately made with little to no clipping to demonstrate proof of concept of cumulative drag reduction techniques. The craft runs on only liquid fuel, 2 RAPIER engines and a NERVA engine. Demonstrating the RAPIERSPIKE engines which has significantly reduced drag compared to naked RAPIERs. Craft File: http://s000.tinyupload.com/index.php?file_id=01081702413893749625
  4. How in the world did you even manage to launch that 4-drill mining rig?
  5. If I'm not mistaken, the landing gears now have mass. I mean come on, even struts have mass and even affect drag...
  6. I don't see a problem with this because I use planes as another avenue of transport to get stuff into space.... aka SSTOs...
  7. I stick to stock parts (except for UI inputs like mechjeb, Kerbal engineer, Kerbal alarm clock, and various other things like sound effects for immersion). This is mainly because I plan to share my crafts and other lessons learnt from the base game. So for the crafts I make and the ascent profiles I have, they all need to be standardized and not force people to download mods they might not want.
  8. His audience demographic that he caters to are teen girls and boys. I can't relate to that sort of stuff anymore.
  9. I have. It's still the same, except that landing is now significantly harder because of the terrain and the fact that brakes and airbrakes are worthless in the thin atmosphere to slow you down in time. Still need to pack heavy chutes like I did in 0.25.
  10. I am more concerned with the NERVA engines overheating when it's not supposed to because you have cryogenic fuel cooling the reactor down in the first place. The engine is only supposed to overheat when you run out of fuel to cool down the unit.
  11. I'd say something in the top 50, due to the sheer amount of game's I've played over the years. The poll really depends on the age of the person and the amount of exposure they've had to other games.
  12. To illustrate how significant and detrimental struts are to efficiency, I have made a comparison. Here we use 11 struts for a total weight of 0.55 tonnes, compared to the second craft which is carrying a FL-T100 tank with 0.5625 tonnes of fuel. That means the strutted craft is still 0.0125 tonnes lighter. Let's see how this goes... Launch conditions: It becomes immediately clear that weight for weight, the struts slow you down more than actually carrying rocket fuel. This is a significant finding and now makes it more crucial that crafts now use as few struts as possible. The un-strutted rocket on the left here, leaving the strutted one in the dust.
  13. MYSTERY SOLVED I just had the same thought too. I made a new testing craft with mirrored rockets called the Strut Tester. You will be interested in these results... This mirrored configuration has the basic rockets supported by launch clamps instead of struts to maintain stiffness. During launch: As expected, they both break the sound barrier and have identical performance. We have mirrored vessels with a SINGLE strut connector. The parent craft being the left rocket. Launch state: The differences are incredible. The parent craft holding the strut connector is significantly slower than the right craft. We now have a configuration where the LEFT rocket is a parent of one strut connector, while the RIGHT rocket is also a parent of a strut connector. 2 strut connectors in total. Launch state: Remarkable. With both rockets as parents, the rockets perform identically. We've now determined that the strut connectors are causing the differences in the tests, but how big of a difference do struts matter on crafts? We compare the strut with placing a Advanced Inline Stabilizer on the right rocket to weigh it down. The left rocket is a parent to the strut connector. The Advanced Inline Stabilizer weighs 0.1 tonnes. It is twice the weight of a strut connector which is 0.05 tonnes. The right rocket on a whole weighs 0.05 tonnes more. Launch state: As observed, the left rocket carrying the strut has an initial gain in speed and height. The striking and most surprising issue occurs when the heavier rocket suddenly gain speed and outperforms the supposedly lighter rocket and zooms to a higher apoapsis. Conclusion: We have a EAS-4 Strut Connector that weighs 0.05 tonnes which are usually strapped to the outside of rockets to make them stable. Compared to adding a Advanced Inline Stabilizer which weighs twice as much in an inline configuration at 0.1 tonnes, strutted rockets experience a significant drag disadvantage compared to unstrutted rockets carrying heavier parts. My findings suggests that excessive use of struts in your rockets will actually slow them down. Struts actually impose a significant aerodynamic drag on the craft. I will be removing all struts from my aircraft and redesigning them to require less to see how they impact SSTO performance. Test craft used is provided here: https://dl.dropboxusercontent.com/u/16683090/KSP/Strut%20tester.craft
  14. Sure thing. The right hand rocket is the one with inwards displaced fuselages. Same result though....
  15. Negative. MJ was not used in these tests. I also actively switch crafts to check if they are at full throttle, to which they indeed are. The craft is available for you to test and see for yourself too
  16. An interesting thought would be to offset an object out and then offset it back in again, you could in theory, make the craft have less drag for the same look.... *shrug*... Needs moar testing..... TO THE VAB!
  17. I've actually considered this by switching crafts at launch, but the results were the same...
  18. I've been doing some aero testing for the difference between radial attchments, parts joined by attachment points, part offset of attachment points and their effects on aerodynamics. I've seemed to have stumbled on something unexpected. What I have here are 2 identical crafts where one has its boosters centrally attached to an adapter with attachment nodes, and the other where the boosters are also attached to attachment nodes, but have been radially displaced by the offest tools. Initial predictions would be that the one with the centrally placed stack to travel further, faster... Or at the very least both rockets will travel the same. However, by a strange stroke of oddity, the one with the displaced stack flew consistently higher and faster with each repeated test. I have no explanation for this, or why the game would decide that displaced fuselages attached to nodes would make a more aerodynamic craft.... If anyone can shed some light on this, I would very much like to know. I will attach the craft I have in this post for others to test here: https://dl.dropboxusercontent.com/u/16683090/Untitled%20Space%20Craft.craft EDIT: Mystery solved on page 3
  19. The nosecones reduce drag when they are attached to an attachment node of a stack. When you start adding rockets to the sides, they have their own drag calculations because the game considers it another vessel adjacent to the original vessel. Lets for example say that the central stack, the middle rocket has a drag value of 1 and has the drag reduced by 0.5 with a nose cone. That alone now has a drag of 0.5. When you add 4 boosters to the side, all with their own nose cones, the drag for each of them are also added to the whole craft. The central stack (0.5) plus the other 4 stacks that are considered separate entities (0.5 x 4) which is = 2.5 units of drag as a whole. The game applies the 2.5 drag on the ship. It doesn't matter what orientation or rotation you apply to the boosters to make them look like they are behind something, they will still induce that amount of drag. Now, if you were to instead combine all the boosters under the central stack using a 4-way adapter, the drag now becomes a total of 0.5 because they are part of the central stack joined by attachment nodes. The rocket should fly faster and higher. I know this is completely weird and unintuitive, but that's how the game engine currently sees drag.
  20. The game only recognizes nosecones when they are attached to attachment points. If they are not placed on attachment points, they are considered radially mounted and will induce drag. I've made a thread about it here: http://forum.kerbalspaceprogram.com/threads/122574-Radial-mounted-parts-on-atmospheric-flight-performance
  21. It doesn't matter either way. The game engine does not recognize parts behind other parts for drag occlusion. It only applies for parts obstructing engine thrust.
  22. This is mainly for SSTO spaceplanes as they often straddle around a TwR of 1. Rocket SSTOs are just another way of getting cargo into orbit, but using a larger craft and with a lot more fuel.
  23. As of 1.0.2 KSP has had a revised drag model which greatly reduces the effectiveness of SSTOs with radial mounted tanks or engines. This thread serves as a rough experimental observation to illustrate how SSTOs are now needed to be adapted for 1.0.2. As of testing various crafts, the ascent profile is a 30 degree climb up to 8000m where the pitch is lowered to 15 degrees. During this time as speed picks up, the sound barrier is (usually) broken and at around 20,000m the pitch is raised to 20 degrees, intakes closed and the RAPIER engines switched to rocket mode. All crafts used RAPIER engines and the desired apoapsis is 70,000m. (1) The limiting factor for pre-1.0 SSTOs was the soupy drag, which requires all crafts to clear the soupy atmosphere as soon as possible to gain speed. However, engine thrust was constant and overscaled in high atmosphere. (2) During 1.0 the limiting factor was overheating. (3) 1.0.2 the limiting factor is now back to drag. Thrust is limited to speed and dependent on breaking the sound barrier, after which above 20,000m or so the engines die out. Beginning with a one engine craft, we have one with radial mounted tanks and intakes. It makes it to orbit, but had to take a longer time to break the sound barrier. Rearranging the parts around to make a single tubular shape (Minus 1 intake and 2 Type A nosecones. These are considered negligible.) We also switch out the NCS adapter for a FL-T200 tank in order to fit the 80 liquid fuel for an inline configuration. Liquid fuel was adjusted for 80 units to compensate. Surprisingly at 5000m it was already breaking the sound barrier. The ascent profile needed to be adjusted higher in order to prevent overheating. This craft too makes it to orbit, the ascent profile was a lot easier to manage although the craft aesthetics leaves a bit to be desired. This is a 3 engine 23.934 tonne craft. This is to illustrate a brute force approach to breaking the sound barrier. Here at 5000m it has broken the barrier. The ascent profile remains unchanged from the default pitch off stated in the above text. Note the drag values. It makes it to orbit. A second test with only 2 engines reveals that the craft is no longer able to break the sound barrier or reach orbit (even though it is 2 tonnes lighter due to 1 less RAPIER). This is a craft of similar weight to the 3 engine variant but at 22 tonnes (due to 1 less RAPIER). All fuselage and intakes are place on attachment nodes and are inline. Ironically called the 'Shortbus', it miraculously breaks the sound barrier easily on 2 engines. And later reaches orbit with a full FL-T800 fuel tank. Preliminary impressions: 1.0.2 makes drag a very powerful force that craft designs need to be designed around. Getting into orbit with reasonable amounts of fuel depends on leaving the draggy atmosphere as soon as possible. In order to leave the atmosphere ASAP, you will need to break the sound barrier ASAP. To break the sound barrier ASAP, you will need to reduce drag at all costs. Currently inline placement to attachment nodes reduces this significantly. Attachment nodes are a requirement for the game to recognize an inline attachment to avoid drag. The game however does not recognize clipping and does not recognize inline placement of parts using the offset tools. This means that a streamlined looking craft will perform draggier than a not-so streamlined looking craft using attachment nodes. For a minimalist like me, there are 2 methods of getting payloads into orbit. If radial attachments of engines/nacelles/fuselage is unavoidable in a design, a brute force approach is required to overcome excessive drag, regardless of the use of aerodynamic nosecones or intakes. If a craft is an inline sausage, the number of engines can be reduced significantly to 2 RAPIERs. This also saves on the dead weight of having 1 extra engine in orbit. I will perform more tests and will continue reporting in this thread. Other reports are welcome.
  24. I think having to wait around for 10 minutes for your satellite to complete a planetary scan as utterly retarded. A better system would be to have the scanner scan the planet in the background while you're off at the launch site doing other productive things like launching other rockets rather than sitting around like a dunce.
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