A Fuzzy Velociraptor

You can have the fuel enter at right angles to the oxidiser; it is not uncommon especially with "staged" engines like HTP-RP1 style engines. However the injector systems will not be the shower head style yall are most likely using and will instead use an impinging injector style which will stillpromote adequate mixing. However it will tend to increase the heat flux into the chamber wall especially since those mixures will be hypergolic. I dont know enough about your system. Given the earlier pictures I imagine performance if not your goal that just a straight showerhead style should be easiest to produce. Also what are the planned size of you injector holes as that will be the main thing that will affect your mixing. I also dont know the size of the diagrams you have whether they represent the entire plate or if they represent a close up on a triplet. They tend to use impinging feed systems because it increases performance. The size of the engine doesnt significantly affect the desirable type of injector (splash plates excepted). The size of the injectors are very small generally in the range of three hundreths of an inch with the whole doublet/triplet/pentad less than a quarter inch.

Actually it was directed at ap0r. Your engine looks very rough that it is difficult for me to tell exactly what is going on there that I can't really give a recommendation.

How did you determine your heat flow into the cooling system?

The phenomenon you are referring to is called "blowapart" and can be seen with hypergolic mixtures. I think that the greater number of impinging streams (doublet, triplet, pentad etc) the greater the likelihood of blowapart. Also the greater the number of impinging streams the more heat will be transferred into the injector plate. With non-hypergolic mixtures I believe the flame front is designed to be maintained further down the combustion chamber to allow for more complete mixing and avoid blowapart though I have only ever worked with hypergolic mixtures. As for the topic, yes that can happen. The combustion can cause an acoustic vibration which can affect the injector system slowing down the injection and causing a larger vibration. To prevent this the injector flow is "decoupled" from the combustion chamber so that vibrations in the combustion chamber will, ideally, not affect the combustion chamber. To do this the pressure drop across the injectors is normally made to be around 20% of the total pressure such that fluctuations in the chamber pressure will not affect the flow rate across the injectors. Huzel and Huang do a good job explaining this in DESIGN OF LIQUID ROCKET PROPELLANT ENGINES (1992) pgs 104-116,

Because the plot data looks like a porkchop.

If you use GMAT youll want to calculate some values with patched conics or so help you itll be almost impossible to get a convergence. Also start with a porkchop plotter. STK can also do some of what your looking for but GMAT is better for transfers. Also make sure you have quite a lot of ram or it may take a very long time to converge.

Sounds a lot like the missions for the RASCAL competition this past year.

At least for the US, the maximum height for a rocket to be classed as an amateur rocket according to the FAA is 150km (93.2 statute miles). Even if you could achieve orbit at that altitude and impulse restrictions it wouldnt be a very long lasting orbit. Also I imagine a number of additional restrictions would apply there. Though in general going to space is hard but relative to orbit it is very easy. You only need about 1.4km/s delta V to the Karman Line but you'll need about 9.5-10km/s to LEO. 31-1-6. DEFINITIONS a. Amateur rocket – an unmanned rocket that is propelled by a motor or motors having a combined total impulse of 889,600 Newton-seconds (200,000 pound-seconds) or less; and cannot reach an altitude greater that 150 kilometers (93.2 statute miles above the Earth's surface. b. Amateur Rocket classes: 1. Class 1 - a model rocket that uses no more than 125 grams (4.4 ounces) of propellant; uses a slow-burning propellant; is made of paper, wood, or breakable plastic; contains no substantial metal parts; and weighs no more than 1,500 grams (53 ounces) including the propellant. 2. Class 2 – a high power rocket, other than a model rocket, that is propelled by a motor or motors having a combined total impulse of 40,960 Newton-seconds (9,208 pound-seconds) or less. 3. Class 3 – an advanced high power rocket, other than a model rocket or high-power rocket. c. Launch Vehicles. Vehicles built to operate in, or place a payload in, outer space or, a suborbital rocket. Part 400 requires that launch vehicle operations be licensed by AST

There might be life but certainly no intelligent life.

It sort of does. It cuts off its arms after they are used (the side boosters) then cuts off one leg (main stage) so the other leg (second stage) can work then cuts that off a releases a payload.

I actually completely forgot about it but saw it climbing as I was driving down US1.

I for one nominate @B787_300 as he fits those qualities and I wouldn't mind if he went away forever even if I would miss him after like 6 months.

4. Most of Protons failures were in the early years of the Proton when launch failures were more common than they are now (though they still have one failure in some form about once a year). There was one launch vehicle proposed, Aquarius, which was expected to fail in 30% of the launches though the cost per kg was expected to be at 1000USD. 5. That was also a 5kg sample. Most humans don't weigh 5kg. I'm a small human and I weigh about 80kg (though I could stand to lose 25kg). Humans also require a lot more support for things like air and water and generally not being dead. In the project we could get away with an Ariane V because there was very little supporting equipment required and the payload mass was extremely small. You could certainly send human ashes to Mars with something like our project but I feel like that somehow wouldnt count. So I don't think that project is actually really very relevant here. Well it is possible we could land on another planet in route but I have a strong feeling someone will be getting fired if that happens.

Im not entirely sure what you are saying here. Unless you plan to run it as a monopropellant you will need an oxidizer. Also I don't think @KSPNewbie intends to fly this system beyond the lower atmosphere if they intend to fly it at all. Neat, I'd love to hear more.

Generally you require special piping and gauges with gaseous oxygen. Honestly hydrogen peroxide is not particularly easy to get your hands on and the catalysts required can be fairly expensive (though I don't know prices of permanginate solutions or catalyse) and while it is safer than many other propellants it can still do serious damage. Honestly I think your easiest bet would be to just use Nitrous Oxide and Propane. They're both relatively safe, easy to acquire, and won't require any particular special equipment for their use.

Orbital Mechanics for Engineers by Howrad D. Curtis is decent. The examples can be rough though where jumps are made that you may not see.

Armadillo Aerospace has used a ballute in the past. I dont know of any other space vehicle uses though they have been used for bomb retardation. It wont let me post both at the same time or edit so sorry if this doesnt merge my posts. Stig A III Jan 28 2012

Damn that real life always getting in the way. What sort of element designation/configuration are you planning on using for the injector system?

Looks nice and should hopefully be easier to manufacture on your end. Have you begun to address your injector system yet?

I'm fairly sure it requires a little more than 4km/s to get to the moon. White Dragon: Yes though its not what you expect.

1) Yes, I expect I did. I didn't intend for you to do the math by hand which I why I dropped you the link to NASAcea which can do that. For one you could do your own system which could be safer and cheaper than GOx Methonol. GOx also requires special fittings which are quite a bit more expensive. 4) A 15 degree conical nozzle doesn't have a sharp corner at the throat, it is still rounded there. From braeunig:

Well I prefer you wouldn't as this is the only sub-forum I visit, except that one time @Frybert sucked me into another thread in the games forum. It is true that quite a lot of things here could be answered with a google search though there are a number of things that may not be able to be answered easily. Depending on the amount of exposure someone has to a topic will also determine their ability to find and learn things from a google search. If you haven't had enough exposure to a topic and the requisite knowledge to understand that topic and google search is ultimately useless. A lot of time people come in and ask questions or propose ideas that they may have some understanding of the topic but may have large holes in their plans or math or missing bits of knowledge. There are some of us here that have knowledge and experience in certain areas and can help to address those issues or at least point them out or help to send them in the right direction with a quick explanation or links to papers and books. Also while a lot of things regarding rocket science can be answered with a google search everything that goes into rocket engineering and making all your systems work together and how they all work is not something that be regularly be answered especially not when you want to apply it to specific circumstances. This game has helped get so many young people excited about space or at least more curious and I think that is fantastic. Some of the people here may eventually want to pursue careers involving space be it engineering or physics, sounding vehicle, space launch vehicles, satellites, deep space systems, etc and I think that is fantastic as well. I can sit here and help people better understand how certain systems, namely propulsion, work and function and maybe they learn something valuable from it, and if they do that can only be good. I honestly don't care much for the game itself, I haven't played it much in like 3 or 4 years, except for sitting near @B787_300 and mashing the space key to blow up his rockets, but I think that having this subsection of the forum to talk with these people who are excited about space, real space, and real engineering is a great thing.

What was the program/source for that image?

Given my knowledge of Star Trek, either interfere in its development, mate with it, or get into a fight with it, most likely all three.

So I finally actually read the whole thing. There are a couple things I noticed. 1) You can actually predict the performance of an idealized one dimensional case for varying O/F ratios. Also the stoichoimetric ratio will the hottest reaction but it may not have the highest exit velocity. For instance hydrolox engines run fuel heavy because the unburnt hydrogen significantly reduces the average molar mass of the products of reaction. A good tool for determining this stuff is NASAcea. You will likely have to follow an iterative process to get the maximum results 2) I notice you vary your units a lot, this can be a significant problem where your numbers can be significantly thrown off. If you are following that first 70pg PDF you found (I forgot the name) some of those equations are empirical equations, and many already have gravitational factors built in and should only be used with English Engineering units and not SI or British Gravitational. 3) How long are you planning on having the engine burn? If the burn is short enough you may be able to use a cheaper material and rely on the thermal mass/thermal inertia for cooling the engine. Otherwise you are significantly complicating your system. 4) Also there are tool available, some of which are free, which can help with that nozzle design, alternatively you could just use a 15 degree conical nozzle which would be significantly easier to machine on your part. 5) Also make sure to figure out how you are addressing your pressurant issue as it will significantly alter the performance and stability of your engine. If you are planning on just using the pressure of the GOx note that pressure will drop along an adiabatic expansion and most fixed injector systems will be very unhappy about that and will suffer from a large drop in combustion efficiency and stability.