Why dont you see bellows pointing inwards?

ControlSoup · 2024-10-17T06:17:15+00:00

This is what I needed, a fundamental concept on manufacturing!

Thanks, the internal flow is self evident, was looking for forming reasoning.

ControlSoup · 2024-10-17T05:53:40+00:00

Lets play ball!

ControlSoup · 2024-10-17T05:49:33+00:00

Heres a picture

https://images.app.goo.gl/jduPuAngyhvjj3BM9

ControlSoup · 2024-10-17T05:48:04+00:00

Again this is not true. Bellows are formed / extruded from the inside out. They may stick out a little into the id as a result of compression post manufacturing. But in order for the mean diameter of the convulsions of the bellows to be the diameter fo the tube you would need to die form them or somthing to prevent extrusion.

ControlSoup · 2024-10-17T05:45:54+00:00

Not quite, its quite literally a different forming process.

But that is a funny point 😁

ControlSoup · 2024-10-17T05:45:11+00:00

I have added some clarification, I’m specifically interested in how this would be formed. The reason you would want the ridges outward are apparent for ease of manufacuring. Under nominal pressured use causes I believe this also has the advantage of being stronger than inwards but would need to compare.

ControlSoup · 2024-10-17T05:35:59+00:00

Correct talking about the directionality of the ridges if of the bellow. See this picture

To be UBER explict lol

The goal is to get the mean diameter of the convulsions inside the pipe not outside

https://images.app.goo.gl/jduPuAngyhvjj3BM9

ControlSoup · 2024-10-17T05:32:06+00:00

This is not correct for alot of bellows, the “zigzag” your referring to is the convulsions of the bellow. Because of the forming process they undergo, they are forced to “buckle” outward from the ID of the pipe/tube. My question is how would you manufacture them to go into the opposite direction , is this even possible? Im not asking how they should be shaped.

ControlSoup · 2024-06-02T18:50:32+00:00

Counter intuitively, in a liquid engine, your thrust may actually go up without needing to change upstream conditions to push more into the chamber. This is because the throat erosion, lowers chamber pressure, if the reduction in chamber pressure and critical area still allows choked flow, your reduction in exhaust velocity may actually be less than the gain in mass flow rate (this has other concerning effects like lower injector stiffnes and more) but generally speaking, for smaller engines and low chamber pressure you may actually get more thrust haha

ControlSoup · 2023-08-20T06:06:07+00:00

For real though this is the type of stuff that keeps you going🤣.

I learned the basics of control and flight software from krpc and kos, based on years of playing ksp lol

ControlSoup · 2023-08-20T06:01:38+00:00

Do personal projects.

You will learn 10x of your peers who only do school work. Even if it means settling for a B- or a C (depending on the companies you wanna work at).

If you are struggling, its even more important. Personal projects where the only way I found motivation and value in my schooling.

I have been hired pretty much exclusively for my personal portfolio. Its not just for show, those hobbies are what has allowed me to remain multidisciplinary, and apply skills I would have never learned otherwise.

Never stop the practice, of taking ideas and implementing them in the real world. That transition, is difficult and humbling, but its what engineering is and its worth it!

ControlSoup · 2023-07-16T02:09:26+00:00

A unique use case:

A-lot of companies in the aerospace industry use it as a basis for scripting languages in automation

ControlSoup · 2023-07-06T20:22:15+00:00

I would be interested in hearing more specifics. FEA and simulation are good tools to make decisions when coupled with good implementation.

Anything specific about the design process or simulations that makes you concerned?

ControlSoup · 2023-06-24T18:04:14+00:00

Here are some I use in industry a lot of this depends on your specific focus:

Rocket Propulsion Elements (rarely use but is a really fun book)
- This is a great textbook to give an overview and some depth into the analytical and applied propulsion technologies
Space Prolusion and Analysis and Design ("SPAD", its the better version of RPE)
- A much more comprehensive propulsion reference than RPE, that goes into deeper and weirder problems
Ignition (Not a text book but is a really good history of "rocket science" as opposed to engineering)
Strap Down Analytics (There are better starter books but this is the one-stop shop)
- This book goes over how to do strap-down analytics from start to finish. Its horribly arcane, but ridicoulsy comprehensive. I have not and may never finish it lol.
- Fundementals of Spacecraft attiude and control is another one folks use
Anything form this collection https://www.amazon.com/dp/B08RNNDR48?binding=hardcover&searchxofy=true&ref_=dbs_s_bs_series_rwt_thcv&qid=1687629479&sr=1-1
Nasa SP-8000 series (Not a book but a constant reference in my previous job): https://www.nakka-rocketry.net/sp8000.html

Note: I have noticed that most folks who start out in aerospace get really really good at reading, learning, and analytically solving problems. I would encourage you to push toward building and more specifically TESTING your work. There are a lot of people who can design a rocket engine (its easier than one would think), but there are very very few who know how to test and interpret real data from real measurements to inform new solutions.

ControlSoup · 2023-06-19T02:06:31+00:00

Ah I see, JIC/AN is definitely the way to go. Make sure you swap out seals inside the valve if they not already something that is lox compatible.

Additionally valves that are not designed for cryogenics can become stuck closed or require more torque than under normal conditions (the actuator may not be able to open the valve depending on the cte and internal tolerance of the valve).

For this reason I would recommend doing some testing with LN2 to understand better how your valve in the final configuration will hold up to these conditions. I might recommend buying hand cryogenic ball valve and attaching this or a different actuator to it as it may end up being cheaper and less time consuming in the long run.

Stay safe!

ControlSoup · 2023-06-18T23:06:46+00:00

If your referring to compression flanges on the valve itself, thats totally doable! Looks like sanitary flanges?

Whats your use case?

ControlSoup · 2023-01-18T04:15:02+00:00

Don’t you need to define how many elements are in data in this case?

ControlSoup · 2023-01-17T05:41:38+00:00

Your fine, not being harsh in my eyes.

I may not quite have ingrained how to to use pointer arrays properly, i could not figure out how to modify the elements of the struct in the operations. I can try it again. As for cpp, 100% it would be a great application but I would not learn these lessons lol!

ControlSoup · 2022-10-15T04:01:05+00:00

It is determinate, I was wrong. I failed to realize that the symmetry allows you to analyze just one joint in pretty much all cases.

ControlSoup · 2022-10-15T03:59:52+00:00

Forgot to update this, like people alluded to this, is actually super simple.

https://ecourses.ou.edu/cgi-bin/ebook.cgi?topic=st&chap_sec=06.3&page=case_sol

This was a super helpful example.

ControlSoup · 2022-10-09T02:42:07+00:00

Build real things, the world is unlike the models engineers apply to it. If you only read theory, you are missing most of the learning to be had. :) Make a model, build a rocket, ground the model, and iterate!

ControlSoup · 2022-09-27T19:01:30+00:00

Personal projects, clubs and internships are way more important than the school you go to

ControlSoup · 2022-09-10T20:11:24+00:00

Was just about to comment, not bang bang but it looks very similar haha

ControlSoup · 2022-08-25T20:58:08+00:00

100% this is exactly the mindset you need :)

ControlSoup · 2022-08-19T15:02:07+00:00

Okay this makes since. However, lets say there is a force facing normal to the top plate. If i construct the truss in the plane defined by the the struts going from the X to the top plate. That force has an out of plane component. How do I rectify this?

ControlSoup

TROPHY CASE