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How to start a rocket engine

everydayastronaut.com

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Re: How to start a rocket engine

#51

Post by Merad »

sbradford26 wrote: post #38
fnordpiglet wrote: post #21

Earlier quoted context omitted.

I mean what issues would power of 10 fractions have in floating point after all?

If I have data going out on a data bus in grams/second, but someone reading that data in a different sub system reads it and thinks it is kilograms/second because that is the default unit they use then you have an issue. The actual conversion of the bits isn't the issue it is that certain systems might use different units internally and making sure those conversions are done correctly. It is much more an engineering…

Pretty sure GP was making a sarcastic comment referencing how floating point is notorious for subtle rounding issues when handling values that have an exact representation in base 10 but a repeating pattern in binary.

Re: How to start a rocket engine

#52

Post by ghostpepper »

LargeTomato wrote: post #50

I'm surprised at the amount of people who enjoy EDA. I find him very irritating. Most people at my small space company find him extremely irritating. He is not a rocket scientist. He parrots silly buzzwords like "biomimickry" like a fanboy, not an engineer. He suggests things to Elon for how to do rockets that are just pants-on-head dumb. His blind fanboyism and arrogance irritate so many people who work in space. I'…

Didn't he suggest something to Elon that Elon immediately decided to alter on an upcoming rocket? Doesn't sound like he knows nothing..

Re: How to start a rocket engine

#53

Post by NikolaNovak »

LargeTomato wrote: post #50

I'm surprised at the amount of people who enjoy EDA. I find him very irritating. Most people at my small space company find him extremely irritating. He is not a rocket scientist. He parrots silly buzzwords like "biomimickry" like a fanboy, not an engineer. He suggests things to Elon for how to do rockets that are just pants-on-head dumb. His blind fanboyism and arrogance irritate so many people who work in space. I'…

Not sure, I have not encountered this author before, but frequently in many fields a fan / enthusiast perspective is different than professional / expert perspective.

Re: How to start a rocket engine

#54

Post by oh_sigh »

LargeTomato wrote: post #50

I'm surprised at the amount of people who enjoy EDA. I find him very irritating. Most people at my small space company find him extremely irritating. He is not a rocket scientist. He parrots silly buzzwords like "biomimickry" like a fanboy, not an engineer. He suggests things to Elon for how to do rockets that are just pants-on-head dumb. His blind fanboyism and arrogance irritate so many people who work in space. I'…

His audience is fanboys, not aerospace engineers. So it makes perfect sense.

He may be a fanboy but that fanboyism got him a trip to the moon.

Re: How to start a rocket engine

#55

Post by Gravityloss »

LargeTomato wrote: post #50

I'm surprised at the amount of people who enjoy EDA. I find him very irritating. Most people at my small space company find him extremely irritating. He is not a rocket scientist. He parrots silly buzzwords like "biomimickry" like a fanboy, not an engineer. He suggests things to Elon for how to do rockets that are just pants-on-head dumb. His blind fanboyism and arrogance irritate so many people who work in space. I'…

Compared to average YouTube, TV or magazine content he is excellent and in depth.

Re: How to start a rocket engine

#56

Post by MarkusWandel »

You can watch the whole thing from the very genesis of the turbopump powered liquid fueled rocket. The British did a very thorough documentation project on the German A4 / V2 rocket after WW2 and it's all accessible to the public.

http://www.v2rocket.com/start/chapters/backfire.html

In particular, the pyrotechnic igniter that is mentioned in the article as still in use by the Russians was copied directly from there. Here's a direct link to the spot in the video where it is assembled for use.

https://youtu.be/V_fPdXLx48c?t=2097

Re: How to start a rocket engine

#57

Post by rpmisms »

LargeTomato wrote: post #50

I'm surprised at the amount of people who enjoy EDA. I find him very irritating. Most people at my small space company find him extremely irritating. He is not a rocket scientist. He parrots silly buzzwords like "biomimickry" like a fanboy, not an engineer. He suggests things to Elon for how to do rockets that are just pants-on-head dumb. His blind fanboyism and arrogance irritate so many people who work in space. I'…

He's incredibly annoying, but he knows his shit. He's like a crypto influencer who also happens to be a brilliant engineer. I watch his content because it's insanely informative, even though he reminds me of every con artist I've ever met.

Re: How to start a rocket engine

#58

Post by numpad0 »

sbradford26 wrote: post #43
chriswarbo wrote: post #31

Earlier quoted context omitted.

> You might have one thing measuring fuel burn rate in grams/second and another in kg/second This sort of redundancy is a big problem with metric (e.g. hours, litres, tonnes, etc.); and why it's better to stick to the SI subset. http://www.chriswarbo.net/projects/units/improving_our_units... In particular, SI is "coherent" https://en.wikipedia.org/wiki/Coherence_(units_of_measuremen... - There is only one unit for ea…

When designing new systems it is best to clearly define the expected units for everything clearly at the start. SI units are great but sometimes they are not great for the specific use case. When measuring high power systems like power plants or EVs kW/MW/GW are a more appropriate unit versus Watts. In embedded systems you have limited bandwidth having to have large variables just to store values in SI units is a was…

INT_MAX is usually 2147483648, which means a "power" figure in Watt can handle anything from a laptop CPU to a Chernobyl power plant. FLT_MAX and _MIN are e+38 and e-38 so couple digits over and under(within 32bit precision).

Have you actually had that kind of unit confusion in metric, or inferring from your experience with Imperial system? It kind of just seems to reinforce suggestion that Imperial system having bunch of redundant or weird units IS the problem.

(for your defense: try [METRIC_UNIT]/h and /s. e.g. km/h often used for display in slow vehicles and m/s used for calculation motions of fast objects are kind of confusing.)

Re: How to start a rocket engine

#59

Post by skazazes »

chasd00 wrote: post #28

I think there was a russian engine that literally had 2x4's on fire stuck in the combustion chamber in place of torch ignitors or TEAB. If anyone's interested the experimental high-power rocketry hobby is pretty fun, there's a lot to learn and hack on. A lot of people focus on propulsion and formulating, profiling, and flying various solid fuels they develop themselves. This guy is highly regarded https://www.nakka-r…

You probably already know of him, but you should check out BPS Space on youtube if you enjoy long-form video edutainment. Much like Tim Dodd, Joe makes videos full of detail and information about topics he is clearly passionate about. In the case of BPS Space that is pushing the limits of amateur rocketry in a uniquely hacker/programmer friendly manor.

Re: How to start a rocket engine

#60

Post by peterfirefly »

LargeTomato wrote: post #49
samwillis wrote: post #3

Earlier quoted context omitted.

> His interviews with Musk are a treasure trove as well, whatever you think of Musk. My main take away from those interviews is just how knowledgable Tim is, he's able to engage in low level and in depth conversations about how these engines work. It's not just superficial high level knowledge from making videos, he is thinking himself how to optimise and improve these things, and leading that conversation. The passi…

To be honest he's regurgitating a lot of information. He has large gaps in his knowledge but presents himself as extremely knowledgeable. Understanding a rocket engine as a layman is easier than understanding a diesel engine. EDA acts like he's a genius but he is not. I work in space. Some of my coworkers have met EDA. He is insufferable and extremely arrogant. A very difficult person to be around.

> He has large gaps in his knowledge

Yes.

> but presents himself as extremely knowledgeable.

No.

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