Questions tagged [engine-design]
Questions regarding the design or design process for a propulsion system.
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Using of the rocket propellant for engine cooling
Why does liquid space propellant make a good engine coolant? I was researching the regeneratively cooled nozzle and combustion chamber on the Merlin 1D when I found this out. I do know that the pipes ...
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Can the bleed-off fuel in an open expander cycle be substituted for another liquid?
In all expander cycles, fuel is used as the working fluid to generate the pressure difference necessary to drive the pumps. This makes sense in a closed expander cycle as it'll eventually be used in ...
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What is the relation between chamber pressure and expansion ratio?
I've always assumed that the expansion ratio of an engine equaled the pressure inside the engine over the atmospheric pressure, but I'm not sure this is right, could someone check me on this?
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Is it common and good engineering for a pair of cables to be easily plugged into each other's connectors in modern spacecraft
Space News's Human error blamed for Vega launch failure
Analysis of the telemetry from the mission, along with data from the production of the vehicle, led them to conclude that cables to two thrust ...
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How do we maintain the RPM of turbo pumps in liquid rocket engine?
How do we maintain the RPM of turbo pumps in liquid rocket engine? And how do we control it? And in the case of electric pump fed engine (like Rocket Labs's Rutherford engine) is easy but how we do it ...
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What is a throat plug used for?
This cutaway drawing of the F-1 injector plate has a "throat plug insert" annotated. What is a throat plug? What is it used for?
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using Tesla turbines to pump rocket fuel
From what I've read, tesla turbines are extremely lightweight and even more efficient (about 95% compared to 90% of turbopumps) when compared to turbopumps, and their bladeless design would also ...
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Preventing hard starts using varied propellant/ O/F ratio?
From what I've heard, hard-starts are a very common, particularly in less refined amateur rocket engines, and the only way to avoid them is to either start the engine on an extremely low flow rate or ...
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MT-135 Sounding Rocket info / design
I'm searching for any design file or deep-info on the MT-135 rocket, the fuel used, engines, engines info, any thing really. I have deep-searched on tons of sites but I just find few missions that ...
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Combination of fuel cells and electric motors - whether it has been used as part of an electric pump-fed engines?
In electric-pump-fed engines fuel pumps are electrically powered and batteries are used as source of electricity. Yet there is another source of electrical energy which could be used in theory - fuel ...
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What do the RD numbers of Russian rocket engines mean?
Most Russian rocket engines have a name on the form of for example RD-107 (РД-107).
But apart from different engines having different numbers, how is the number chosen?
All RD-2xx engines appears to ...
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What is the effect of poorly choosing L* in combustion chamber design?
I am a member of a university rocketry club and we are in the process of designing a liquid rocket engine. One of the previous propulsion leads did the primary conceptual design of this engine in RPA. ...
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Microwave drive for cubesats
Theory: how is this?
I was doing a lot of research about the EmDrive thruster, i find 50% papers says that it work and other 50% saying that the "thrust" is a product of the interaction with ...
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what is the ISP loss associated with pressure fed engines
Numerically, what is the approximate loss of overall system specific impulse associated with pressure-fed rocket engines, not only as a result of the low chamber pressure but also of the additional ...
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Low-pressure pump-fed rocket engine?
I saw the above suggested in LEO on the Cheap. In P.130 it says:
A compromise between high-performance/lightweight pump-fed vehicle designs
and cost-optimized pressure-fed vehicles with heavier ...
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Contracting rocket engine nozzles
The efficiency of rocket engine nozzles depends greatly on their expansion ratio an how well the ambient pressure matches the rocket nozzles exit pressure. An optimal expansion ratio means that there ...
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What is the feasibility of a graphite chamber, nozzle and bell walls
What is the feasibility of using graphite, particularly variants that are easy and affordable to acquire, in a combustion chamber, nozzle and bell as well as nozzle extension? Does it need ...
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How much cheaper are pressure fed engines compared to other cycles (e.g. staged combustion, gas generator, electric pump-fed)?
It's well known that pressure fed engines are mechanically simpler, and therefore cheaper than pump-fed cycles (although pressure fed has worse performance). However, I haven't found any sources that ...
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Why don’t any engines use turboelectric oxidiser pumps?
Most larger liquid-fuelled rocket engines1 use fuel and oxidiser turbopumps driven by the hot, high-pressure gasses produced by burning said fuel and oxidiser:
The gas-generator cycle burns some of ...
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Trying to make a program to calculate (liquid) engine size. Can you please help me check for any problems?
So as the title says I am trying to write code to calculate engine size and some other parameters.
For the equations, I used mostly :
Sutton's Rocket Propulsion Elements 8th Edition, and for the ...
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Have there been rocket engines designed for diesel? What ISP theoretically possible?
Have there been rocket engines or even test engines that have used diesel as a fuel? If so, what oxidizer had they used and what ISP did they achieve? If not, is it possible to say what ISP is at ...
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Why use nozzle extensions for ULA's Vulcan; why not make them this long in the first place?
This answer to What is the difference between the Vulcan 562 configuration and the Vulcan 5H2 ("Heavy") configuration? explains that the 2nd stage nozzles were modified by extending them, ...
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Merlin combustion chamber pressure
What is the combustion chamber pressure for Merlin?
I mean the average and the maximum
The Raptor engine was tested with a maximum 330 bar. I would like to compare them
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What methods have been used to cool aerospikes on paper and in reality?
I am doing a research project and need to mention what methods have been used to cool aerospikes (toroidal is the brute of the paper but I suppose methods for cooking toroidal Aerospikes could apply ...
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How does the open expander cycle separate the fuel for the pump and combustion chamber? [closed]
I'm designing a single open cycle expander rocket engine using propane. However, I've been unable to find out whether or not the fuel is split into the turbine and combustion chamber before or after ...
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Engine configuration for lander
Which is a more stable lander design:
1.Single central engine.
2.Multiple engines located near the corners
Following is the design for Tianwen-1, the Chinese Mars lander:
And following is the design ...
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Would rotating detonation rocket engines always require high pressure fuel pumps? [duplicate]
The question Performance of a pumpless liquid rocket engine is thoughtful and provocative and pretty much all answers include a mention of the extremely high pressure necessary to push propellants ...
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Performance of a pumpless liquid rocket engine
Basically all rockets that I know of have a pump feeding fuel and oxidiser into the combustion chamber. The turbopump is one of the most complicated and expensive components of the entire rocket. If a ...
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Viking Lander descent engine design feature
The Viking Lander Terminal Descent Engine (3 per vehicle) was a ~600 lbf monopropellant hydrazine engine with an unusual exhaust system of 18 small nozzles. Multiple sources state that the reason ...
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Where could I find more propellant combustion charts for more different/more broad examples/numbers?
So after asking how I could calculate this kind of propellant combustion charts for different fuels/oxidizers and other ratios and other stuff and getting some really good answers, especially from ...
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Why are stages not connected by the engine nozzle? Why are interstages used?
First, a clarification: I understand the aerodynamic reasons that interstages are used, and I understand that the shockwaves that would be generated without an interstage would wreck the rocket. My ...
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If rocket engines only need fuel and oxidizer, then why there are so many pipe lines on the engines?
If fuel and oxidizer are pumped by turbines to the combustion chamber, then why there are so many pipes around? It should only have a two-cylinder shaped turbine assembly. I doubt there are other ...
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Which are good resources to learn more about the components of a rocket engine?
A detailed and annotated image of a SpaceX raptor engine (found on a SpaceX website) illustrates that in addition to the major components (e.g. pumps, inlets, combustion chamber, nozzle), there are ...
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Is the concept of the Epstein Drive based on actual theorized scientific research which is considered plausable?
I've always found it interesting when we see real life taking its cues from fictional arts, especially when it comes to Science Fiction technology. There are plenty of examples of classic books, TV ...
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What (if anything) limits the efficiency of a rocket engine?
Humans have developed lots of rockets. I observe that in most cases to increase the payload capacity we just increase the amount of fuel.
Is it not possible to exponentially increase the efficiency ...
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How to calculate these engine parameters on my own?
I am a space enthusiast and am intrigued mostly by rockets. I recently found a book HOW to DESIGN, BUILD and TEST SMALL LIQUID-FUEL ROCKET ENGINES and have been fiddling around with rocket engine ...
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Storage density of a Deuterium-Helium 3 fusion pellet
in a series I am working on I will be using a D-He3 fusion drive system (similar to the one in the expanse according to Project RHO). I am under the assumption that the fuel will be stored in a pellet ...
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Pressure withstanding capability
As you can see in this pic, F-1 rocket engine consists of 15 main components. Now, how is it possible to keep all the components together intact in high pressure situations like when the rocket is in ...
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Why does the core stage of the Ariane 5 produce more thrust in vacuum?
In listening to a youtube video that was discussing the Ariane 5, the narrator noted briefly in passing that the Vulcain 2 engine produced more power thrust in a vacuum than it did at sea level. Not ...
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What is an "exhausterator" and what does it do?
I laughed when I first saw the word "exhausterator" mentioned, I scratched my head when I saw it the second time, and I came here after the third.
Besides making me feel like maybe technobabble isn't ...
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How do spherical SRB's compare to long skinny ones? What do their thrust curves look like?
Most SRBs are long and skinny, probably because most are used low in Earth's atmosphere where aerodynamic drag is large.
But here are some very short SRBs, one seemingly spherical except for the ...
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Why was circa 600 volts used for DAWN's ion propulsion?
This answer estimates that the DAWN spacecraft's solar-electric propulsion accelerated about 3 milligrams of Xe+1 per second, using roughly 1350 Watts of electrical power. I estimate that 3 mg/sec of ...
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What is the thickness of a rocket nozzle?
For a university project, I'm working on optimisation of a Falcon-9-like launch vehicle, and one element of that is varying expansion ratios of the engines. This will impact on the engine mass, but to ...
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Calculations needed to full-design a rocket
Suppose I want to put a cubesat in Titan's orbit (saturn's moon). and I want to calculate what rocket power I need, how do I calculate it? Where do I begin? total mass of the probe or delta-v needed? ...
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Are regneratively cooled nozzles still modeled as isentropic flow?
In a regeneratively cooled nozzle, there is a transfer of heat from the expanding exhaust to the nozzle (and then into the propellant cooling the nozzle). This is clearly not an adiabatic process. Is ...
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What is the load path for thrust in a rocket engine? [duplicate]
This may be a duplicate of this question but I wasn't sure if I could hijack that one to clarify or regenerate interest there.
What is the distribution of axial force in a combustion chamber? My ...
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Why were later Russian engines inferior to the NK-33?
In terms of thrust-to-weight ratio the NK-33 engine developed for the Soviet N-1 rocket was by far the best in the world at the time, with a thrust-to-weight ratio of 137. But subsequent Russian ...
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Would this 'hybrid expander cycle' engine be practical?
This is another attempt at making closed expander cycle a bit more efficient (the first attempt was here). The design combines some elements of both the open and the closed expander cycles (hence the "...
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Saturn V and Atlas Engines exhaust issues
This is a follow up question to "Organic Marbles" answer to my earlier question about the atlas rocket exhaust nozzle, regarding the Apollo F1 thrust nozzles having metal baffles/fins inside to ...
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Atlas Rocket Burning Hose
I was just watching The Right Stuff for the 100th time,and I've always wondered what is that hose spewing flame/burning propellant out of the bottom of the rocket. It's definitely not an engine,and ...
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