IHI RHB5 based turbine

[jamesp]

Hey fellas,

My name is James and I'm from British Columbia, Canada. I wanted to share a project I've been working on for the past couple of years. It's a turbine based on an IHI RHB5 from a Ford Probe, and it will run on diesel. I've finished it to the point that I can test it, but haven't gotten it to run yet, so any constructive feedback would be much appreciated. These are the specs:

-IHI RHB5 turbocharger
-3.0 Gal/hr oil furnace nozzle
-Walbro 255lph fuel pump
-Shurflo 8000-643-236 oil pump
-automotive ignition coil driven by a 555 timer and IRFP450 MOSFET
-Arduino and LCD display with K-Type thermocouple for EGT
-5.5" FT with adjustable primary, 10 x 7/32" secondary, 5 x 31/64" tertiary (based on Jet specs)

I have gotten flames, so I know that the ignition works and that I'm getting adequate atomization. Just need to tinker a bit to make it run I suppose.

One issue that has come up is if there is a risk of my combustor bursting, given it's size. My dad feels it is just too large an enclosed space should the right combination of air and fuel vapor develop inside. Is anyone able to weigh-in on this?

Thanks!

James

[racket]

Hi James

How thick is your outer cans wall ??

Could you supply your compressor inducer diameter and your turbine exducer diameter please , this will give me an idea of potential flows and whether or not they are a reasonable match for a gas turbine engine build .

Could you please explain your "adjustable" primary air flow ??

Cheers
John

[jamesp]

Hi John,

I'm not really sure exactly how thick the can is (can't measure it now because I'm in Alberta for school), but it is built out of an old air compressor tank. Maybe ~1.5 mm.

Compressor inducer is 39 mm, and the turbine exducer is 43 mm.

Looking at the pictures above, you may be able to see how I mounted the FT to the combustor cap. The FT is held off the cap by springs, and the gap formed serves as the primary 'hole.' I've welded 3 nuts to the FT, and with bolts going through the cap and threading into these nuts, I can adjust this gap.

Hope this is useful. Thanks!

James

[racket]

Hi James

The can should be strong enough .

Inducer/exducer match is a little marginal if using high temperatures with a jetnozzle installed but it shouldn't stop you getting it fired up without one fitted .

The Primary air quantity is critical to good combustion , ...................with a 39mm inducer of area 1195 sq mms , the primary air metering area will be 30% of that 1195 , so 385 sq mms , your 5.5" dia flametube will have a circumferance of 439 mm , you'll be needing a gap of ~0.88mm between flametube end and can cap . ...................this going to be difficult to achieve with any degree of accuracy when we factor in expansionary changes when the flametube heats up during running conditions . .......................I'd strongly recommend "sealing" the flametube to the endcap and fit primary air holes in the flametube wall ................and have a slipjoint at the outlet end of the combustor where the gases are funneled into the scroll , there doesn't appear to be a "funnel" on the end of your flametube , we can't butt up a large diameter flametube to the scroll inlet , the resulting vena contracta will probably send your comp into surge as the flow is restricted .

Hope this helps :-)

Cheers
John