scsmith
Well Known Member
Do any of you know what provides better results, the rounded 180 ramp or just adding a curved plate?
There is kind of a trade-off here. A small semicircle (like the RV-8) produces a lot of local acceleration around that tight curve. It won't separate, but it probably over-accelerates and then has to slow a bit as it blends with the main exit flow 'jet'.
A larger, more gradual plate would not have as much overshoot in the velocity, but it would have more 'wetted' area producing skin friction.
Hard to say what the real optimum is, probably somewhere in between. My gut says a 2--3" radius semicircle would be close to best, but I have nothing to support that instinct.