Performance: The RP-4 is designed to be a high performance aircraft.
jsherblon said:Do you need a multi-engine rating to fly it?
rv6ejguy said:As a designer and fabricator, I admire the thought and work that has gone into this aircraft. We think we have it so hard building a pre-punched, pre-designed kit!
I'll go out on a limb and say the surface conduction cooling system will be a total failure with maybe 2000hp on tap. The C of G would seem to be impossible here but I don't think they got this far without considering that. The DO335 had one engine in front and one amidships with a drive shaft- seemed like a better idea.
I think the Macchi MC72 seaplane that still holds that world speed record used two V12s in tandem and surface conduction cooling (with a lot more area and copper cladding) It worked to the tune of 440mph on floats so maybe we shouldn't be so skeptical. http://www.oldbeacon.com/gallery/gallery6/gal6-1.htm
The C of G would seem somewhat forward on this one too but it obviously worked.
Totally impressive in 1934!
Rotary10-RV said:Ross, I'm with you in thinking that the surface cooling system won't work. I don't think the super thin wing will have enough surface area. I don't think they will run anywhere near 2000 HP though. Also, boundry layer is much more signifigant on a wing with lamilar flow. Aside from having to use super strong materials the thinness of the wing isn't that bothersome. Have you ever figured the thinness ratio of a modern MD-80, excuse me a BD-80. Cg is a bigger concern. This plane would have been a perfect candidate for two 20B rotary engines too. The prop looks weird, but borrows from all that UDF work done years ago. I think that will work fine. The design is truly different, I hope it works for them. Good to see a different take on things once and a while.
Bill Jepson
rv6ejguy said:I'm just making a rough plate plate area and Cd guess here. Even with no cooling drag, they'll need 2000+ hp to beat the short course records stated here. They'd have to do 539 mph to take that one. Not sure supercharged V8s will last at this power level for the 100km record. I'm sure you've seen the push/pull twin Wankel powered design on Lamar's site which has never flown?
Cool project. Will it fly? Don't know but I bet it will sound awesome!