I have a stupid idea...what about using a single nozzle and using the counter rotating flows to counter each other as they recombine, with fewer guide vanes?Malish,
when I look at your posts 107, 109, and 112, it appears that you have two sets of duct support blades, one row with 7 and one row with 11. I assume you did this because there is a body joining point right aft of the 5 blade fan and you have to maintain the roundness of the duct at that point/region. In post 107, you say that these counteract the swirl! How is that possible when they are symmetrical/inline with the duct? Your 5 blade fan creates a swirl and there is no counter rotating fan to remove the swirl. Maybe I am misinterpreting your pictures.
Speaking of that, the f-22 does just fine with fixed inlets, it relies on the extra air just pouring off the sides. The external drag is a fraction of the drag of an internal ramp like the f-14. Duct drag and improper dynamic thrust/impulse thrust are absolutely the biggest factors. Note that the most efficient jets have no ducts...all prodded engines...and twin spools that allow for a wide range of dynamic thrust and impulse without a nozzle... But that relies on designs with a hot section.Scrubbing losses on the intake trunk are not insignificant for sure --and separation is also a problem on a non contracting duct more than one with a non constant-decreasing, cross section and is one of the main differences between a ducted propeller (with a bell mouth creating a contracting duct in effect and accelerating the boundary layer by the airfoil effect when the stagnation point is on the outerside of the intake ) and a buried fan - without boundary layer bleeds on the intake and fairly clean flow into the intakes it could be hard to get the optimum blade loadings downstream at all times --the transition from a square section intake to a round disc face also introduces problems (even to standing vortices in the corners --it was Frank Whittle who foresaw this as a problem in centrifugal compressors and was found also in superchargers by Hooker --the Moller Slycar uses the reverse of a round intake to an expanded square exit and this is also a problematic geometry --few other homebuilts have used an internal shrouded propulsor so much will be learnt from this work .
PS there was a Mazda rotary powered 'ducted propulsor' homebuilt flown at Mojave in the early 70s but I haven't heard of it since -any one know details ?
You could have said "The Beginning" at the end of your video. That is my wish for your and your project... Good luck...I know that a lot of "dark areas" in Ducted fan aircraft design. After we came out with final aircraft configuration, first thing we did, is to built 25% scale RC model. This size we picked because it will be as close as possible aerodynamically to a real aircraft. Our main goal was to determent flying characteristic of airframe itself, so we can start to built master model of aircraft and making molds. Same time we're experimenting with ducted fan propulsion system. Model flew very well. We tested it for slow flight, stalls, spin recovery and maneuverability. We're pleased with results. Here is video(sorry for amateur quality):
PJ-II 1/4th Scale Model - YouTube