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Questions tagged [rocketry]

45 questions
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Can a water-pump pump diesel?

After some research, I found that diesel is my choice of fuel. Now I need a way to pump it to the engine. My main constraint is price. So my question is can I use a water pump like one of these, to pump the diesel?
Dat Ha
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Why are rocket engines tested horizontally?

Rocket engine test stands mount horizontally. That's surprising to me given that rocket engines are meant to operate vertically. Doesn't gravity effect any part of the system? Valves, gas mixing, etc.
Chris Noe
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What is the purpose of building multistage rockets, rather then packing more fuel into a single stage?

Reading an article about multistage rockets (not educated at all on the topic), and from the get go it seems to assume they are used/need to be used.
david62225
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Are rocket engines practical for commercial aircraft?

What are the prospects of seeing rocket engines become the standard for commercial aircraft? It might be a dumb question; I really don't know all that much about the topic. The reason I ask is that rocket powered aircraft are much faster—and who…
bobKnowsBest3199
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Why are the rocket exhausts so different from rocket to rocket?

I have noticed that the exhaust flames for rockets can be either everywhere, like in this image or it can be hardly noticeable, like in this video. I am just curious, what makes this difference? Is one better than the other?
John Snow
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Combustion Chamber Back Pressure due to gas injection

I am trying to calculate prior to testing the expected back pressure resulting from injecting gaseous oxygen through an injector orifice (choked) into a rocket combustion chamber before ignition. I have tried using the Borda-Carnot equation with the…
Justin B.
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Propane rocket nozzle material

As far as I know, propane with oxygen will burn at 2800 °C and steel will melt at ~1500 °C. Brass is even less. What I am trying to do is a rocket nozzle. Is there a way I can built this with steel or is it simply too hot? And for the burning…
Dat Ha
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Assuming sufficient electrical power, is an electrolysed oxyhydrogen rocket practical?

Assume we have access to light electrical power e.g. a (hypothetical) small fusion reactor. Is it practical to operate a water-fuelled rocket, in which water is converted to hydrogen and oxygen (or their mix, oxyhydrogen) via electrolysis, which are…
Louise
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Rocket vs aeroplane? Difference in take off?

Although both aeroplane and rocket burn fule and eject smoke but Why aeroplane moves and runs horizontally before take off ?why does not it takes off at its original/initial place just like rocket?
DSP_CS
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Inefficiency of intermittent burn in rockets

Imagine I have a combustion chamber with a nozzle. There is a high pressure oxygen bottle and a high pressure gaseous fuel bottle connected to the chamber. Would the fuel efficiency be lower if I performed combustion in a series of many very short…
Francis L.
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How to minimize temperature increase caused by compression of a cryogenic liquid in a multistage high pressure turbopump?

The cryogenic fuel I'm using is methane at 100 K and 300,000 Pa. Based on my calculations, after compression, the pressure is 55 MPa and using the ideal gas equation the temperature is approx. 800 K. I need to keep the methane at a temperature of…
Matt01
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the speed of the exhaust

This is from Stephen Hawking's latest book; Brief Answers to the Big Questions. The speed at which we can send a rocket is governed by two things, the speed of the exhaust and the fraction of its mass that the rocket loses as it accelerates.
Harry
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Small oxygen tanks

Does anyone know of any type of small, refillable oxygen tank. I'm trying to build a rocket and the smallest cylinder I could find is BernzOmatic's 1.4 oz. cylinder. A big cylinder isn't really safe for my purpose and I really need it to be…
Dat Ha
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Would an elongated rocket launch tube 'now' be feasible and economical?

The general idea is to make rocket launches far more economical than they currently are... maybe even within eventual affordable range for the general populace! The goal of a tube is to significantly reduce the energy needed for the rocket to…
hamstar
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Crossover distance for ballistic missile vs cruise-missile

For payloads of 100kg and 1000kg, what is the cross-over distance at which the weight of the fuel used to travel a certain distance is equal for a ballistic missile and a cruise-missile/plane? Assume that both the cruise-missile/plane and ballistic…
Dan Sandberg
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