Post by lofi on May 18, 2016 5:24:03 GMT -5
Hello everyone! First of all, thanks to all who've been sharing their knowledge and experience, and giving us long time lurkers such interesting reading and research material.
After many years of reading, dreaming and soaking up as much information as I can, I'm finally setting up to attempt a build. I've tried to pick up as much as possible, but there are a few things I could do with some clarification on if someone would be so kind
Turbo choice: Turbine exducer 25% larger than compressor inducer. This has been tricky to find. Turbo diesel units certainly seem more promising than their petrol counterparts - presumably they need a larger hot side to get the power needed out of cooler, slower moving diesel exhaust? I can find turbos with around a 15% ratio, and have my eye on an HX35 at the moment. Is this likely to be suitable? The info I've found seems to indicate comp inducer 52mm, turbine exducer 60mm, but I won't know for sure until I've actually got it in my hands. A/R also unknown at this time.
Combustor: I've spent a few hours plugging figures into JetSpec and drawing up combustor designs in OnShape. Does the combustor length need to include or exclude the "funnel" shape to transition from the round combustor to the rounded rectangle of the turbo inlet? Is 316 stainless acceptable to make the flame tube out of, or is there a better choice? Is there best practice for axial placement of the three sets of holes, and similarly for their pattern? Is a simple radial set OK, or are they better staggered in a zigzag?
Fuel delivery: Assuming diesel - a single central injector at the top of the combustor, protruding axially with radial holes? I assume these need to be sized for the desired fuel delivery rate and pressure, but I've no uncovered how to calculate this. I gather from my reading that higher pressure gives better atomisation, so is there an ideal sort of pump to be designing around.
Oil: I think I've got this covered with a Honda CBR1000 oil pump. It's self contained, has a chain drive and an integral relief valve.
Intended use: Initially just for the hell of it, but I was toying with the idea of getting it to turn a generator via a (possibly turbo based) freepower. I'm no fan of the clacky little diesel unit that powers my mobile genny, so thought a turbine replacement could be quite fun. Reacting to changing loads could be an interesting one... Anyway, this is putting the cart before the horse. Building a functioning engine comes first!
Before I go, a little about me: I'm what you might call a hobby engineer. I have a little workshop with the usual engineering tools, and have spent many years tinkering with, restoring, converting and modifying cars. I even spent a few years helping out at a local motorsport firm building drift and drag racing cars, so I know my way around a turbo! Steam locomotives are also a passion of mine, and I spend a lot of time volunteering on overhaul and restoration projects.
Thanks again, and apologies now I've just realised how many questions I've just thrown out there! Hopefully they're intelligent ones.
All the best.
Ian
After many years of reading, dreaming and soaking up as much information as I can, I'm finally setting up to attempt a build. I've tried to pick up as much as possible, but there are a few things I could do with some clarification on if someone would be so kind
Turbo choice: Turbine exducer 25% larger than compressor inducer. This has been tricky to find. Turbo diesel units certainly seem more promising than their petrol counterparts - presumably they need a larger hot side to get the power needed out of cooler, slower moving diesel exhaust? I can find turbos with around a 15% ratio, and have my eye on an HX35 at the moment. Is this likely to be suitable? The info I've found seems to indicate comp inducer 52mm, turbine exducer 60mm, but I won't know for sure until I've actually got it in my hands. A/R also unknown at this time.
Combustor: I've spent a few hours plugging figures into JetSpec and drawing up combustor designs in OnShape. Does the combustor length need to include or exclude the "funnel" shape to transition from the round combustor to the rounded rectangle of the turbo inlet? Is 316 stainless acceptable to make the flame tube out of, or is there a better choice? Is there best practice for axial placement of the three sets of holes, and similarly for their pattern? Is a simple radial set OK, or are they better staggered in a zigzag?
Fuel delivery: Assuming diesel - a single central injector at the top of the combustor, protruding axially with radial holes? I assume these need to be sized for the desired fuel delivery rate and pressure, but I've no uncovered how to calculate this. I gather from my reading that higher pressure gives better atomisation, so is there an ideal sort of pump to be designing around.
Oil: I think I've got this covered with a Honda CBR1000 oil pump. It's self contained, has a chain drive and an integral relief valve.
Intended use: Initially just for the hell of it, but I was toying with the idea of getting it to turn a generator via a (possibly turbo based) freepower. I'm no fan of the clacky little diesel unit that powers my mobile genny, so thought a turbine replacement could be quite fun. Reacting to changing loads could be an interesting one... Anyway, this is putting the cart before the horse. Building a functioning engine comes first!
Before I go, a little about me: I'm what you might call a hobby engineer. I have a little workshop with the usual engineering tools, and have spent many years tinkering with, restoring, converting and modifying cars. I even spent a few years helping out at a local motorsport firm building drift and drag racing cars, so I know my way around a turbo! Steam locomotives are also a passion of mine, and I spend a lot of time volunteering on overhaul and restoration projects.
Thanks again, and apologies now I've just realised how many questions I've just thrown out there! Hopefully they're intelligent ones.
All the best.
Ian
