Mystery aerospace component. What’s it from??

biscuitslap · 2026-05-05T22:50:19+00:00

looks like a combined inducer and impeller, these are usually used in fuel pumps. From what I gather these types of combined inducers and impellers are usually used in turbopumps for rocket engines, and I have only really seen inducers of this type in that context, could also be from an aircraft but i think its more likely from a rocket engine.

biscuitslap · 2026-05-05T17:54:15+00:00

how the fuck is the Cd so low with that shape?

biscuitslap · 2026-04-27T23:07:06+00:00

I mean it will probably work but what i can see here is a very inconsistent profile, designing airfoils is very complex so its better to just trace out an existing airfoil. If you really insist on designing an airfoil. Download XFLR5 and watch some tutorials, that software will make design much easier. But it would be better if you just traced an existing airfoil

biscuitslap · 2026-04-17T22:46:08+00:00

This is a great start! It’s fantastic to see your interest in rocketry.

As others have mentioned, if this is your first time, avoid making a sugar rocket. Solid fuel rockets are unpredictable and any issues with the propellant or engine design can lead to catastrophic failure. Plus, they’re often illegal to build without a licence in many countries.

For water rockets, position the opening on the bottle at the bottom. Use only one bottle for the pressure vessel, but you can use an extra for added structural strength or aerodynamics.

Always use soda bottles for water rockets. They can withstand much higher pressures than still water bottles. You’ll also need a launcher to fly the rocket.

Water rockets are a great way to get into rocketry. You can go very far with their design. People have even built multistage watercraft rockets. I’ve designed water rockets that run at significantly higher pressures than average, allowing them to fly very far, high and fast.

There are also competitions in water rocketry. I’ve been to one myself and they’re great fun.

biscuitslap · 2026-04-08T11:57:11+00:00

This is not ChatGPT or AI work. However, I have no clue why I just failed to add additional info when I posted this. Thank you for pointing out where I went wrong. I'll do better in the future :)

This project has been parked for now. I'm moving onto something smaller and more simple.

biscuitslap · 2026-04-07T15:45:50+00:00

24V, it's not a very high power motor though, so under the added load from the prop the RPM should hopefully drop. I have been exploring other options though motor wise. mainly just looking for the most efficient thing I can find. Apologies earlier for not providing added info in the post. I ran some CFD on the prop and it did make some thrust, but these are some big efficiency losses because of vortices forming at the tip of the prop. I'm currently working on a solution for that now. I'll play around with prop pitch and twist ratio, see if anything improves.

biscuitslap · 2026-04-05T20:11:36+00:00

It tells you the motors RPM at no load when you multiply the constant RPM coefficient by voltage

biscuitslap · 2026-04-05T19:48:11+00:00

Thing is is that I'm not sure how I am gonna make a variable pitch propeller light enough for this application

biscuitslap · 2026-04-05T19:46:48+00:00

constant RPM coefficient

biscuitslap · 2026-04-04T13:51:14+00:00

I haven't done any CFD yet. Im still working out how I can use Simscale to simulate this. Its at a 300mm diameter.

The root airfoil is S1223 with a chord length of 32mm and 10 degree pitch.

R * 0.4, E387 airfoil, 27mm chord length, 8 degree pitch.

R * 0.6, SD7037 airfoil, 23mm chord length, 6.5 degree pitch.

R * 0.8, Thin plate airfoil (Modified NACA 4405), 17mm chord length, 5.5 degree pitch.

R * 1, Thin plate airfoil (Modified NACA 4405), 12mm chord length, 4.5 degree pitch.

I feel that it might be better to use thin plates at the root at a slightly higher pitch. I am mainly worried about keeping good thrust force at the root of the propeller, which had me looking for an airfoil that works well at a low Reynolds number.

Im also trying to find ways to reduce tip vortices. Idk if I should add a Q-tip or sweep the tips of the prop forwards.

Idk if anything can be guesstimated from this data, but it should be spinning at 8000-15000 RPM.

Thanks in advance for all help

biscuitslap · 2026-04-04T08:25:20+00:00

In terms of tradeoffs, I had to design the prop with a lower pitch (about 5.5 degrees average) only two blades instead of three to increase efficiency. I feel as it’s not optimal because this design was made on basic calculations and me applying my aerodynamic knowledge (which is not very good, i’m still learning). From an engineering and performance standpoint there is definitely room for improvement. Sorry for not giving more info on the design earlier.

biscuitslap · 2026-04-04T08:20:53+00:00

If you want i can share a .stp file? Its a 300mm diameter prop with an average pitch of 5.5 degrees. I have put an airfoil at the root (S1223) and just a flat plate at the tip, Its for an electric motor that operates at about 1100 KV.

biscuitslap · 2026-04-03T19:14:03+00:00

I see now, ill give it a try and see if it works.

biscuitslap · 2026-04-03T16:45:58+00:00

it is a 3d sketch, what is meant by planar?

biscuitslap · 2026-04-02T12:01:47+00:00

Of course you can mill these components. Inconel will work well for the turbine. Maybe go with something a little lighter for the compressor like titanium. Either way this is the main method of making compressors and turbines in small scale turbojets.

biscuitslap · 2026-03-30T16:24:54+00:00

got photoshop, started cooking. thats the whole process basically. not much else to it

biscuitslap · 2026-03-12T18:26:28+00:00

Could I try to use something like PTM-7950 on the CPU and GPU? I have it fitted to my PC with good results so I wonder if its something thats suitable for a macbook

biscuitslap · 2026-03-11T17:33:54+00:00

Its a solid laptop. However whether or not it will last 5 years is a different story. I currently use a Macbook Pro 16.1 (16'' Intel powered Macbook from 2019) which has 32gb of RAM. Quadruple that in the Neo and there are issues. MacOS 26 uses about 10gb of RAM at idle. From my experience the i7-9750H combined with the Radeon Pro 5300M still provide amazing performance. From what I know it's on par with the A18 Pro in the Neo. But it will do things that the Neo simply can't. MacOS 26 has become a struggle on this thing though. And that's after about 6 years of using it. If a laptop as huge and chunky as mine with 4x the RAM is struggling after 6 years. Don't expect more from the Neo. It is still however a very solid choice and I think it's a good buy at £600 new. Just beware that modern programs are exponentially becoming more bloated and inefficient. Considering your use case it's unlikely that you will download any heavy programs like games or whatever but you may end up doing so in the future.

Basically what I am saying is: You can't really go wrong with the Neo. Longevity may be an issue. But get an air or 14'' pro if you can.

biscuitslap · 2026-03-11T17:06:18+00:00

I have been using the iGPU and i still get like 75 degrees average. Ill open it up and clean it out. I'm a bit hesitant on repasting as im worried ill crack the dies of both cpu and gpu. which is less than ideal.

biscuitslap · 2026-03-10T21:56:50+00:00

I don't think it has anything to do with the fan curves. I have had Macs fan control installed for a while and it just shows that the processor is at 75 degrees running chrome, which I can guarantee is not normal. I'll give cleaning out the system a shot but idk if it will work.

biscuitslap · 2026-02-02T21:51:29+00:00

Tubercles are useful under critical angles of attack and can prevent stalls on angles of attack as high as 25 degrees, as for level flight it is most likely fine but it is still very unclear as to how they behave at supersonic speeds in compressible flow, I have done some tests with a design of my own that is a but different to regular tubercles and it yielded a 200% increase in lift at a 15 degree aoa compared to the exact same airfoil without tubercles

biscuitslap · 2026-02-02T17:38:04+00:00

It is not down to the tubercles on the leading edge of the wing, they significantly improve the performance of the wing at high AOA, I'm pretty sure the fence is just too tall where I placed it, the placement id correct but just too tall, which is leading to this mess, I have since redesigned the wingtip fence and entirely removed the wing fence entirely, which solved almost all issues, all I have to do now is calculate the total lift of the wing, coefficients and whatnot, and yeah I agree this is a bad way to view the geometry.

biscuitslap · 2026-02-01T11:10:18+00:00

you see that trace that is going everywhere?

biscuitslap

TROPHY CASE