Can anyone tell me what the most fuel efficient PJ design is? There are so many designs out there but from what I can tell they all gobble the fuel. I have several ideas on how to make them ore efficient but I want to start with one that is better than most to begin with. I ultimately want to use it for a small manned aircraft. I want to be able to carry enough fuel for a one hour flight. I have helped build six original design experimental aircraft but have never built a engine or a jet.
I need to build an engine in the 75-100 lb thrust class. If I had a lot of money I would buy a pair of turbo jets which are atleast three times as efficient as PJs. If I had unlimited money I would build a small turbo fan which is atleast twice as efficient as a turbo jet. Of course i live in the real world and have both limited time and money. If I hope to perfect my airframe design with a PJ and then in the future when I have more time and money I'll work on other engines to fit on a proven airframe. I would love to have a three hour range so that I could actually go places and not just fly around the airport.
I am just guessing but it seems to me that the designs with a larger valve area in proportion to size of the combustion chamber would be more efficient by getting more air into the chamber faster but i dont know. It also seems that those with slightly smaller diameter exhaust would help raise the preasure in the combustion chamber allowing a slightly leaner mixture.
I need to make up some graphics of my ideas to post so some of you guys who have been doing this for a while can take a look and let me know what you think.
Brian
Fuel efficiency?
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