rv969wf
Well Known Member
FUEL INJECTION NOZZLES Pressurized for fuel economy and HP
I've seen a few Experimental airplanes with ram tubes tied to the fuel injector nozzle bodys to help with atomization of the fuel at the nozzles that extend towards the cowl inlets and I'm curious what testing has been done with this.
(Atomization is common practice to inject the fuel into the combustor (or premixer) through a nozzle, which atomizes the fuel. That is, the continuous stream of fuel is broken up into a mist of tiny droplets. There are many types of nozzles, some of which rely on very high feed pressures to atomize the fuel, and some of which rely on assistance from steam and air to effect good atomization. Generally, the finer the spray produced by the nozzle the better the combustion process.
What I've seen is maybe only one or two injectors with these tubes that extend to the front of the cowl inlets and some of the other injectors are not done this way. I understand that at high altitude the injectors act quite differently and do not atomize the fuel as well at low altitude. Turbo charged engines have different injector nozzles for this reason so that they can receive pressurized air at the nozzle body to help with this.
Question: how many EXP have used turbo charged style injectors on normally aspirated engines with another source to pressure the body of injector to help with atomization at high altitude? I have some ideas on this but I'd like a little feedback. I'm thinking about fuel economy and a small horsepower increase at high altitude if the nozzles were pressurized on a normally aspirated engine. Thanks
I've seen a few Experimental airplanes with ram tubes tied to the fuel injector nozzle bodys to help with atomization of the fuel at the nozzles that extend towards the cowl inlets and I'm curious what testing has been done with this.
(Atomization is common practice to inject the fuel into the combustor (or premixer) through a nozzle, which atomizes the fuel. That is, the continuous stream of fuel is broken up into a mist of tiny droplets. There are many types of nozzles, some of which rely on very high feed pressures to atomize the fuel, and some of which rely on assistance from steam and air to effect good atomization. Generally, the finer the spray produced by the nozzle the better the combustion process.
What I've seen is maybe only one or two injectors with these tubes that extend to the front of the cowl inlets and some of the other injectors are not done this way. I understand that at high altitude the injectors act quite differently and do not atomize the fuel as well at low altitude. Turbo charged engines have different injector nozzles for this reason so that they can receive pressurized air at the nozzle body to help with this.
Question: how many EXP have used turbo charged style injectors on normally aspirated engines with another source to pressure the body of injector to help with atomization at high altitude? I have some ideas on this but I'd like a little feedback. I'm thinking about fuel economy and a small horsepower increase at high altitude if the nozzles were pressurized on a normally aspirated engine. Thanks
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