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Post by areacombustor51 on Sept 17, 2013 10:23:25 GMT -5
Hello my name is Blake and I have been researching the turbo jet engine on and off for about two years. I'am a welder and have around six years experience in fabrication and all welding techniques with TIG being my favourite. This will be my second attempt to build a turbo jet. After purchasing a used variable vane diesel turbo and running my testing I realized the seals were blown in the turbo and quit the project. The trick with the engine is the combustion camber and I have redesigned a new camber using the ram jet design. I have purchased a another used turbo off of a John Deere tractor with zero shaft play. I'am here to learn more about fuel sources and the location for the injection of the fuel itself and what fuels are the best to use. Rumor has it kerosene is the fuel of choice and some type of pressurized fuel injection. Goal for me is to use a old school bowl float carb. I have yet to complete sustain the idle of the turbo but I have learned through trial and error what will need to be done in order to build a fully functional turbo jet. The variable vines allow for control of the boost/ thrust and I would like to figure out a way to fuel the jet using a carborator setup through the inlet of the compressor. I'am glad I found a forum about this topic and I'am here to learn and discuss the future of the internal combustion engine. I think it's awesome there are people out there doing his stuff. This being just an intro you will here from throughout the forum updating with pictures and other topics of discussion. My goal of the turbo jet is to use the heat source to create steam and reinvent the steam engine using the turbo as the heat source of the application. Somehow pushing steam through and ordinary combustion car engine. Like atmospheric positive pressure of forged/ boosted combustion engine. The steam replacing the combustion of fuel. The steam alone pushing the pistons and turning the crankshaft eliminating the use of gasoline and possibly reengineering the 4 stroke engine. The strokes Suck, Squeeze, Bang, Blow. With the steam turbo the compressor of the turbo is the suck. Squeeze is the charge of the compressor pushing the pistons down. Bang is the the flame of the exhaust turbine. Blow the pushing force of the jet engine. Some of you may read this and be confused as all get out but I typed this while I was brain storming. It will make sense someday. Watch me I have a plan.
Thanks Blake
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Post by racket on Sept 17, 2013 16:47:39 GMT -5
Hi Blake Welcome to the Group :-) Have you also checked out our "Sister Site" tech.groups.yahoo.com/group/DIYGasTurbines/ for more information ?? You can't use a carburetor feeding the compressor as it'll produce a combustable mixture with ALL of the air exiting the compressor , the resulting combustion gases will be at too high a temperature for the turbine wheel to survive ,it'll melt , ...... we only need to "burn " ~30% of the air , the other 70% must NOT have fuel in it , the 30% will need a correct air/fuel ratio of ~15:1 for good combustion , and yes , kero is an ideal fuel , diesel works well , so does diesel with 10% petrol/gasolene mixed in . Looking forward to your build Thread :-) Cheers John
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Post by areacombustor51 on Sept 18, 2013 12:39:55 GMT -5
Hi Blake Welcome to the Group :-) Have you also checked out our "Sister Site" tech.groups.yahoo.com/group/DIYGasTurbines/ for more information ?? You can't use a carburetor feeding the compressor as it'll produce a combustable mixture with ALL of the air exiting the compressor , the resulting combustion gases will be at too high a temperature for the turbine wheel to survive ,it'll melt , ...... we only need to "burn " ~30% of the air , the other 70% must NOT have fuel in it , the 30% will need a correct air/fuel ratio of ~15:1 for good combustion , and yes , kero is an ideal fuel , diesel works well , so does diesel with 10% petrol/gasolene mixed in . Looking forward to your build Thread :-) Cheers John Well huh. This is my rough drawing of my combustor. Looks like I'll be mixing all the air. I have test ran it with the other turbo I had and didn't melt the turbine, but that was ran with propane. So I understand the Air fuel ratio 14.7 is a clean burn of fuel. Will I run into problems due to not enough cool air. My design is A B would be the way to get the 30% fuel to air? These are the traditional designs right? I wanted to go with more or a feel flowing rather than the air running into the side of the flame tube it be forced through the combustion camber
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Post by areacombustor51 on Sept 18, 2013 12:49:06 GMT -5
The beginning of my madness.
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Post by areacombustor51 on Sept 18, 2013 12:56:13 GMT -5
Inlet of the combustion camber Outlet to turbine
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Post by racket on Sept 18, 2013 17:36:08 GMT -5
Hi Blake
Your "A" and "C" drawings are basically the normal setup except that your "A" "cone" is a bit short for combustion to take place in the upper primary portion and dilution in the lower tertiary zone with those larger holes .
Propane will allow a poor combustor design to "work??" due to its very forgiving characteristics of fuel/air ratios and extremely fast combustion , but kero or diesel isn't as forgiving with regards the F/A ratio and needs more space and time to burn , your flametube will need to be "right" if you want the engine to perform to its potential .
Cheers John
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Post by areacombustor51 on Nov 12, 2013 16:41:59 GMT -5
I build this today and tested it. I researched and noticed jet cambers have air cooling jackets. So I built my burn cone and stacked on a cooling camber. The cooling camber cone is 4 1/2 and the burn cone is 4 1/4. So a very small gap between the the tubes. Any ways i tested it and the flame did not travel up into the burn cone. The fuel ignited at the end of the camber the two cambers. I haven't installed an ignitor in the burn cone. Could this correct why the fuel is being burnt at the very end of the two camber exits? Rather than the flame burning in the combustion camber. I have videos and id like to post to show the difference from my original "A" design. Which showed amazing results. Wished I would have just built the jet engine with my original design.
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Post by racket on Nov 12, 2013 19:19:17 GMT -5
Hi Blake
Your air velocities are too high for combustion to occur where it should in the Primary Zone and is occurring at the combustor outlet where speeds have dropped to acceptable levels and/or the F/A ratio isn't correct until reaching the outlet .
We need to displace our primary combustion zone from the secondary and main dilution tertiary zones so that air velocities are low enough for combustion , your "cone" with all of the air transfer holes close together won't work .....................this current flametube is too radical :-(
Cheers John
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Post by areacombustor51 on Nov 13, 2013 9:39:37 GMT -5
Thanks for your input. I'am going back to my old design that seemed to work just fine. What is the formula to calculate for the size of my combustion camber. My inlet flange is 3.5x 2.75. I think this is the dimensions you use to figure right?
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Post by areacombustor51 on Nov 13, 2013 9:40:54 GMT -5
Thanks for your input. I'am going back to my old design that seemed to work just fine. What is the formula to calculate for the size of my combustion camber. My inlet flange is 3.5x2.75
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Post by areacombustor51 on Nov 13, 2013 10:04:36 GMT -5
Rather than cutting up my new designed. I've already started the traditional design with the inlet of the compressor housing on the side of the combustion camber. My outter cone is a littler bigger than a gallon. So what size and where do the holes need to be placed for an efficient burn canister. The image is about the best I've found to what I want to build. From what I can tell there is a gap up by the fuel injection. How big is that gap? Is one end the end by the inlet of turbo. Is that welded solid. So the air coming in either goes through the holes or in through the top by the fuel point.
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Post by racket on Nov 13, 2013 20:24:16 GMT -5
Hi Blake Checkout Jetspecs www.nuclearprojects.com/jetspecs/flametube.php for design parameters . A lot of guys use a "flat head" on the combustor , it becomes the end of the flametube as well , or you can use a flametube that has an air gap between its end and the end of the combustor , if this is done then its possible to incorporate air swirl vanes around the fuel nozzle , its more complex but it works better. Cheers John
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Post by areacombustor51 on Nov 14, 2013 10:33:23 GMT -5
Awesome
Thanks
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Post by areacombustor51 on Nov 14, 2013 10:39:16 GMT -5
I figure the inducer is the size if the turbo inlet. This turbo I got is a diesel it's got two inducers. The small one is 3in and the outside is 6in. So what do I use or the inducer size.
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Post by areacombustor51 on Nov 14, 2013 11:55:28 GMT -5
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