Sage

Only 5k tris, I think I've decimated it fairly well (more than most stock models, but I've played with mods that have pieces in this range. And in ksp part polys tend to add up only to relatively small numbers compared to most games, and the biggest performance hit is usually the ground of the planet you're on)

Nope, actually I used information I found in that incredible book about engine design you linked there, plus looking at photos of the real things that you can found searching on google and wikipedia

Thanks everyone for the kind worlds I play with a RO-like install in 64* kerbin so I will probably do one when the new RO will come out. Other than that if the RO crew wants to use this in the mod they're free to do it, but I don't know if it fits the bill of being a RL engine Possibly yes, I've several other engines planned, but I've also several exams in my way. Anyway the next one should be an expander cycle engine for vacuum use with extensible shroud. Strange, it should be referencing stock sounds, and it works on my machine. Can someone else confirm this bug? And BTW, if someone wants the .blend or the unity project file, or even an explanation on how I got stuff working just ask!

Just a quick first mod that I did for myself, but I thought that someone might find it interesting so I decided to share. It is just an engine, with a bulkhead of 1.25m but with a thrust intermediate between the skipper an the LV-30, and a better ISP in vac, but lower at sea level https://mega.co.nz/#F!3s0hwAIA!FAeybc3a-SC3VReaEb2cjw drop this folder in your gamedata INSTALL HOTROCKETS IF YOU WANT TO SEE ANY EFFECT, SINCE I REFERENCED NAZARI'S EXCELLENT WORK TO MAKE THEM While it's not based on any particular engine, I've tried to replicate RL component and to design it by replicating piping that you see on the real stuff. Below there are the flow diagrams that I sketched (with elite paint skillz) to check if everything was modelled correctly: you can see it's an open cycle engine, with boost pumps pushed by the high pressure fluids at the inlets and a stacked, direct, back to back turbopump design. The fuel flow is used for active cooling, both in a descendent branch that is then fed back to the injection plate, while another part goes directly there while passing from the throat. A small quantity is used to lubricate and control the gimballing pistons and dumped as needed Talking about pistons, the gimballing is animated correctly with flexible inlets as well: The emissives are modelled somewhat accurately, by superimposing a map of the internal heat to a map of the cooling of a determinate part: eyecandy render in blender in game. the emissive are on the gas generator as well License since I need one is CC-BY 4.0 International

Sorry I misunderstood your post then I'm a great fan of borrowing from RL what we need without making it just for its sake too. I guess it comes down to "believability" in the end. Also I was referring to FAR, in fact I'm already playing with nuFAR installed. In stock I can't get my hands on the stability derivatives, that, while is it arguable that presenting them as hard numbers (actually the green/red is wonderful) and with mathematic description only could be a bit unfriendly, they are a must to build a plane, and once you got in a mindset that certain ones affect certain maneuvers they are pretty straightforward and fun to optimize. Another thing that comes to mind about having something modeled against RL physics but with concession to it are radiators and engines that glow with their temperatures. It looks badass, and the first lifter engines overheat put the attention of the player on the fact that heat exists in the game, without hard consequences since the stage is jettisoned early. What is missing now is the temp readouts on parts right-click menu, to further cement this idea while in space too and to give a feedback before everything is in the red zone. Presenting the first radiators and insulators with the nuke engine or shortly before while giving hints in their description on how heat flows could be a great way to ease the player into thinking about heat management.

@Streetwind While I agree with the theory of your post, I disagree that heat mechanics cannot be presented to a player without making them understandable. Stock gameplay is famous to hide information from the player -and I'm still amazed on how they managed to get the orbit thing down right (and still I think that no neophyte ever got docking right without a tutorial) . If we use your reasoning the new aero should be axed in favor of the old one, since they aren't explained at all and one was at least simple, while the new one is often unpredictable also in regard to RL. Heat mechanics are actually much more straightforward to people - thermal mass, conductivity aren't really known by this name but a lot of people have an idea of what they are. What Squad hasn't done right is telling the player that this system exists at all, and it is a shame since it can give a new, fun challenge in building spacecraft, even in non-transient scenarios. That don't work because squad hasn't tweaked values at all initially to allow equilibrium points inside the max temperature range, and it hasn't given us critical parts needed, like radiators and insulators. Now that Nertea is adding those, along with tooltips in the VAB to signal what parts produce heat and dissipate it well (every part should have it, like the mass reading), he is having the problem that large ships ends up being the radiators of a reactor, and bumping up the heat production to fix this put in danger small ships. In the end, instead of pushing the player towards the "correct" assembly - a ship with a hot part with radiators and heat sources insulated from the cold part, the mod is juggling to accommodate every possible design. Now, I never minded Nertea not adding boiloff - it was an unnecessary complexity where there was no need, since heat was modelled poorly and it had no integration with NF reactors. However, now that we have a "realistic" simulation environment the mod ends up not conforming to reality and our expectations of "need radiators for reactors" because large ships act as one - and people were indeed surprised that the tanks could tolerate high temperatures loads, not that the heat was flowing all over the spaceship. So, borrowing from real-life a mechanic that force the engineers to insulate the hot parts from the cold (and Nert has given us an insulators that works wonder!) could prove useful. I don't say it will solve all the problem out of the box, or that it will actually be fun in game, but now there is a reason to try it. Oh, and again, delivery of the info to the player, and a more simple modelling to avoid unnecessary complexity can be done easily. Initially, give to LF and OX the same boiloff rate, so they keep the ratios intact, make boiloff start at a critical temp (not realistic, but this give the players an hard limit and we can have the temp bar popping out when we reach this) and add RCS effects and sounds to the surface of the tank, that start appearing when the temp reach the critical point to give visual feedback that something is wrong. If you can tell me on how liquid boiling, a common sight in everyday life (people even know that during summer some of your gasoline disappears if you don't use your car), presented in this way is less intuitive that plane matching I'll call myself wrong.

just an heads up, the RT-10 seems fixed (for me at least) with the latest Hotrockets

Ehm, this is pretty weird and could be my browser acting up, but I was on KSP store front page when I saw this: I remember seeing those elsewhere, and in fact are one of Nert's first models (at the very beginning of this thread!), so, this beg the question, how exactly they have ended up over there?

@Nathan wanted to ask you about emissiveConstant. While tweaking the NERVA to make it non-explosive I've made something weird. First, I toned down the heat conduction to other parts to simulate cryo isolation, and then I started searching for a way to simulate cooling, that in this design is obtained by the hot fuel leaving the engine. However the engine doesn't have any simulation of something like that, (convection seems to work only in the atmosphere) and I decided to bump up the emissiveConstant to 1.2. While it is a physical abomination it is the only way without a plugin that I found to simulate this behavior within sane working temperatures, and indeed an engine dissipates more heat than simply from blackbody. There is a saner method or am I stuck with this?

I've made some tests and this is not true. Thanks to the new heat system you don't want to tweak the heat production (which is fixed and doesn't vary with the part temperature, which is the factor that determine when a steady state is reached) but the conductivity and the radiation constant in the .cfg. An engine as low conductivity since you don't want that heat to leave the engine up the stack (but if you want to give more option to the player this can be left unchanged and a separate part with low conductivity can be made) and an high radiation which abstracts both the fuel leaving the engine and blackbody radiation. If the parameters are correct the engine will get hotter and hotter, even in "hoverheat" range until the radiation flux balances the heat production. Heat production in the end only determines the kinetics of the process: the higher, the faster the part will reach the critical temperature. It's easy to make passive radiators too, they are the same but with high conductivity and no heat production. What's not possible to do is an active heat exchanger, which needs a custom module. I think it would be suited for NFT, a simple inline part that consumes EC and sucks heat from its neighbors. Attach passive radiators to it you've got yourself an active radiator Hopefully this will be useful to decode the new thermal model, Nertea. If you need other tests just ask!

Thanks for the work Starwaster Well, NTRs like the NERVA are cooled passively by transferring heat to the fuel, and they work properly because the core is hotter than the surroundings and the cooler is dumped to generate thrust All engines tend to have overheating limits, they are usually tailored to the mission profile and you can reach a steady state in which the heat sorce (the core) and the sink (the fuel flow and the radiation from the nozzle) are in equilibrium. This is not possible to emulate with KSP current system, since a part can have only one temperature and all those pieces are one. There are two solutions: letting the engine produce heat and give the player dissipators as a separate part, while maybe adding an inline heat breaker with low conductivity that shields upper part of the stack splitting the core and the engine nozzle into two parts to model them properly, but this causes problems on how to make the module engine work and will take an intermediate dummy resource, as I am pretty sure that engines can't run on LF+heat EDIT: disregard the above, actually radiation in stock is indeed proportional to the temperature, so by tweaking the heat conductivity and radiationconstant in the engine .cfg is it possible to make an engine that reaches a steady state at a temperature inside its max range

I'm surprised on how a similar functionality isn't stock yet, especially since the LV-N now uses only LF.

This is incredible :Q_ Eagerly awaiting nuFAR

thank you for the update, the stock fairings are a big delusion for me Can I advise you to not lose time with that? One of my main gripes with stock fairings is that all of their mass is in the base, as the side is massless, and ejecting the fairings have no advantage whatsoever until you drop the base too. In the end it's your call, but I don't know if it's worth to make something that works like stock and is just going to clutter the part list

Sorry to interrupt a bugfixing thread, but the mk1 pod "stock" reentry attitude is incorrect and resemble the apollo reentry by chance. In that case the pitch was maintained low thanks to a CoM offsetted from the central axis with unsymmetrical distribution of hydrazine in certain side tanks. This allowed the pod to generate more lift and have a less steep reentry and splasdown in american waters of the pacific ocean, but it is not required to do a reentry and the CoM was still very low. If heatshields have mass (use flowerchild patch) you can replicate this with some monoprop side tanks. The mk1 pod with heatshield has the CoM too high and is way more unstable.