/sci/ - Science & Math

an actual jet turbine?

youll never be able to machine everything to get workable tolerances especially the fins

pulse jet would be far simpler but tbh youll prolly just end up killing yourself doing this anyways

I actually worked on a design for a SCRAMJET for a month or two, it's a lot simpler, and more easily done. The cost of operation and testing is ridiculous, because there's no intake for the engine without an exterior plane/other object to propel it into high speed.

>>5369227
good luck getting that working, no seriously OP, I really hope you get it working.

Be interesting to see an amateur pull off a hypersonic wind tunnel. And fuck, hypersonic wind tunnels hardly provide any useful data.

We still got some of the best hypersonic fluid dynamics data from the shuttle. As in holy balls, the engineers at nasa put a turbulent trip on the shuttle wing just so we could get some data. This was AFTER Colombia mind you.

That being said OP, big amateur rockets routinely go supersonic.

>>5369286
Thanks, it really means a lot to have some motivation. I got really good designs for a self cooling engine, and i'm not sure if it's already been done, I don't think it has. I drew the specs for it, I have a good feeling it's practical, cheap, and efficient. I worked on a 3D model in Google's 3D program (Not quite finished) , and I was trying to find a software wind tunnel but didn't come up with any luck.

The cost is really the only thing holding me back.

>>5369180

Turbine blades have a specific geometry to match the flow, this geometry usually contains complex curves.

Turbines run at very high rpm. Even at low rpm there is a significant force on the blades. This matters because blades will extend under stress, dependent on the geometry; at high temperature they will extend even more.

At high rpm it is extremely important to keep everything balanced. This means all blades must be almost identical. During operation the blades will change shape, possibly to the point where it is no longer balanced. The very high energies within the blades make for dangerous failures.

Turbine efficiency is improved by reducing the clearance between the turbine blade and the housing. This increases the risk of contact.

>>5369337 >The cost is really the only thing holding me back.

I doubt this

> I worked on a 3D model in Google's 3D program (Not quite finished)

Please share a screen shot. It will help clarify what you're talking about.

Turbine blade materials are not easily worked with.

http://en.wikipedia.org/wiki/Turbine_blade

>>5369368
Sorry, I meant to clear things up with that.
I worked on a SCRAMJET type engine, the geometry of the turbine was too hard to model.

>>5369337
>> software wind tunnel
you mean cfd? Try openFOAM. It is not easy to use though.

>>5369180
Are you trying to get airborne with this turbine or just generate electricity for yourself?

>>5369372
A test really, as I said it's a pre-alpha build, I plan eventually to get it airborne.

>>5369377
>>airborne
how big?

>>5369377
How big of an engine are you planning to build?

also, 3D program screenshot.

>>5369388
It depends on if its going to be remote controlled or if he's going to be flying in it.

>>5369388
I have no idea yet.

>>5369393
Definitely remote controlled.

>>5369389
SCRAMJET btw, not turbine.

>>5369408
Okay, if its going to be small then you should be able to just weld some pieces of metal together. If or when you make the big one, build or buy a mold and cast it solid - the wheel and the mount separate of course. Here's some information on turbines. Take note on the consistency of the metal. http://www.google.com/patents?id=mGZaAAAAEBAJ&printsec=abstract&zoom=4#v=onepage&q&f
=false

>>5369408
>>5369408
then find some plans for a rc jet turbine online and build that.

>>5369421
oh and when you cast the blades, make sure to make your blades single crystalline.

Is this what you're wanting op?

https://www.youtube.com/watch?v=dTHWBSluUjU

>>5369435
Yes! Pretty much exactly what I want to build. I know I can always buy one, but that takes the fun out of everything (even if it'll probably cost more due to trial and error).

>>5369389

lol it's a shoebox

I was under the impression if something doesn't have to have supreme reliability then using old technology, such as machined or even non-single crystalline blades was fine.

>>5369552
Yes of course. I was just concerned with him wanting to build a craft he could fly in himself. For a small remote controlled jet, soldering it together would work fine.

>>5369180

they have 3d printers that are affordable about 1000 dollars and they can make everything you need with self-replication in a nother year or two so i'd wait if you can but if in hurry go for it will be sweet if it works!

keep me posted OP i'm doing same thing for senior project ME at MIT!

>>5369902

What the fuck sort of post is this?

It's obviously some sort of troll or some stupid with lies put in.

3D printers cost most than 1000 dollars, right now.

They're far from "making everything you need"

>self-replication

>senior at MIT

>>5370061
>3D printers cost most than 1000 dollars
Reprap orca is $700, only prints plastic, needs time to build, configure, learn to use, and optimize.
But it's a 3D printer for sure.

>>5369902
please tell me you are a troll..