|
|
Post by Johansson on Oct 28, 2024 14:58:39 GMT -5
Yup, no more fun with friends for a while now. Just me, late evenings and a pile of metal.   I finished rolling and bashing the combustor together this evening, pretty straightforward since I will use spray nozzles instead of evapor tubes. I added the ear muffs as a size reference.  Finally it is starting to look like a gas turbine!  A side view, there is enough room for the spray nozzle manifold and an air divider that directs a portion of the air towards the combustor inner liner.  I just had to fit the turbine wheel and give her a spin.  I will buy a 230V electric motor to drive the high pressure fuel pump for the initial tests, when everything seems to work I can run it from the turbine shaft by a belt. Cheers! /Anders |
|
|
|
Post by racket on Oct 28, 2024 15:42:14 GMT -5
Hi Anders
Looking good , you're a fast worker :-)
First spoolup before Christmas ??
Cheers
John
|
|
|
|
Post by Johansson on Oct 28, 2024 17:05:01 GMT -5
Time flies so probably not, but perhaps a first dry spoolup could be managed by then. Mostly I need to buy stuff, a 4-stroke engine with a centrifugal clutch and belt pulleys for spinning her up, a 230v motor for the fuel pump, spray nozzles and parts for the manifold, and lots of other bits and pieces. My first chore is to read through a mile of email conversations between us to get back on track, I think we got it all figured out a year ago but I´ve forgotten what we discussed. Knowing what the idle revs will be would help a lot for gearing the starter. /Anders |
|
|
|
Post by racket on Oct 28, 2024 23:37:33 GMT -5
Hi Anders
You might get a reasonable idle at 2-3,000 RPM , there won't be much frictional loss running ball bearings .
Cheers
John
|
|
|
|
Post by slittlewing on Oct 29, 2024 2:01:38 GMT -5
I can’t believe how massive it is 😍😍😍
Glad to see you’re back on with the project! I reckon you’ll have it running before next spring 💪
Cheers
Scott
|
|
|
|
Post by Johansson on Oct 29, 2024 13:11:00 GMT -5
Thanks Scott! Yeah it has shifted my view on big DIY turbines a fair bit. I decided before I started building this engine that I won´t mix my main hobbies, focusing on one thing at a time makes things so much easier and it is waaaay more fun than jumping around between projects. Winter is jet season. /Anders |
|
richardm
Senior Member
Joined: June 2022
Posts: 413
|
Post by richardm on Oct 30, 2024 4:20:04 GMT -5
Yeap! winter is on its way over here too... Time to return the cave....
|
|
|
|
Post by Johansson on Oct 30, 2024 13:09:36 GMT -5
Today I went shopping.
I ordered a 9hp 4-stroke engine with a slipper v-belt clutch, a matching pulley for the rotor shaft, and a 230v motor for the hydraulic pump capable of 6.5L/min @ 200bar.
I´ve also taken measurements for the engine cover, so I can make a set of drawings and ask my old job to cut them for me from 1.5mm mild steel.
/Anders
|
|
richardm
Senior Member
Joined: June 2022
Posts: 413
|
Post by richardm on Oct 30, 2024 15:18:37 GMT -5
HI! 2 questions for you : What do you mean by a slipper v belt clutch ? A centrifugal variable speed like those on a snowmobile or a centrifugal fixed speed drum pulley ?
What is the pulley ratio ? 9 hp.. I bet it s a Honda ...
|
|
|
|
Post by Johansson on Oct 31, 2024 12:00:01 GMT -5
HI! 2 questions for you : What do you mean by a slipper v belt clutch ? A centrifugal variable speed like those on a snowmobile or a centrifugal fixed speed drum pulley ? What is the pulley ratio ? 9 hp.. I bet it s a Honda ... A centrifugal fixed speed drum pulley, it engages at 2000rpm and is rated for 35hp engines so hopefully it won´t wear out when accelerating the heavy turbine rotor up to speed. The max IC engine rpm is 4000rpm and the pulley ratio is chosen so the turbine rpm reaches 2500rpm by then. Nope, a Loncin china motor. A Honda is too expensive.... |
|
jetric
Veteran Member
Joined: December 2014
Posts: 149 
|
Post by jetric on Oct 31, 2024 12:24:04 GMT -5
Hi Anders, Are you going to finish off the compressor by putting the front cover on it and some sort of labyrinth seal to stop the leaks. That compressor needs all the help it can get as you've got next to nothing of diffusion on that axial diffuser. You can't leave it as it is because the amount of air that will leak out of the gap between the comp exducer and the diffuser housing will probably be equal to half the air coming into the comp inducer. Today I went shopping. I ordered a 9hp 4-stroke engine with a slipper v-belt clutch, a matching pulley for the rotor shaft, and a 230v motor for the hydraulic pump capable of 6.5L/min @ 200bar. I´ve also taken measurements for the engine cover, so I can make a set of drawings and ask my old job to cut them for me from 1.5mm mild steel. /Anders |
|
|
|
Post by Johansson on Oct 31, 2024 14:40:56 GMT -5
Hi Jetric, Oh no I won´t leave that gap open, I will make a cover that encloses the compressor wheel completely. Making a labyrinth seal is a great idea in theory, but the sheet metal compressor got a bit of wobble from welding and rolling the outer cone. I will cover it up and make a rim that fits snugly inside the compressor inducer, that in combination with the centrifugal forces will have to do all the sealing. PR will most likely not go past 1.4 so P2 will be in the region of a cow fart. Not even a very optimistic Anders thinks that this compressor and turbine will work for anything other than idling tests. When I get the engine running I will start designing a new rotor set: * The rotor hubs needs to be completely redesigned and made from high tensile aluminum. * The compressor ring will most likely be made from laser cut 3-4mm thick aluminum with "puzzle joints" so I can fit the compressor parts together and tig weld the joints. * I am very tempted to make individual hollow turbine blades from 1mm stainless sheet metal with pin locking to the hub. Cutting flat patterns and using 3d printed press jigs to form the blade shape, then folding the blade and tig welding the inducer and exducer edge. But as usual I invent as I go, so this will perhaps change somewhere down the road. All I know is that I will keep improving things until I can get some useful power from this pile of junk. Cheers! /Anders |
|
richardm
Senior Member
Joined: June 2022
Posts: 413
|
Post by richardm on Oct 31, 2024 16:33:57 GMT -5
About making hollow turbine blades. Could stainless tubing of an appropriate thickness be used? Just a matter of flattening it first and then shaping it Could be made in some length and then cut to desired size. Would save some welding...
|
|
|
|
Post by enginewhisperer on Oct 31, 2024 17:39:20 GMT -5
About making hollow turbine blades. Could stainless tubing of an appropriate thickness be used? Just a matter of flattening it first and then shaping it Could be made in some length and then cut to desired size. Would save some welding... might be possible to make 3D printed tooling inside and out, to end up with a nicely profiled tube |
|
|
|
Post by racket on Oct 31, 2024 17:39:43 GMT -5
Hi Richard
Impulse blading from tubing would probably be the easiest , but the inlet edge would be a tad thick , ..............Anders is such an excellent welder, I don't think he'd have any trouble welding the blades no matter how he made them , I'm very envious of his welding skills ..............LOL, If only I was half as good :-)
Cheers
John
|
|
