ORIGINAL: Nhalyn
A friend have this effect few weeks ago with an electric ducted fan on E-flite F-86 : This is the same setup as on Habu, but on the F-86 it is all ducted from nose to tail cone. It run more quieter with a very different sound and with more efficiency. Why it should be different with kero turbines ?
I have the E-Flight F-86 and compared to the Habu its a dog, compared to the foam ViperJet its two dogs, sits in my workshop unused and unloved, this brings up an interesting fact, the F-86 has smooth inlets and outlets the Habu has just foam surface's in both, this would seem to indicate that the foam uneven surface is more efficient in air flow, now this could be the boundary layer of a rough surface attaching to said surface is more efficient and thiner, therefore, allowing smooth airflow over it, a smooth surface may have a thicker boundary layer, before allowing a smooth transition, I remember reading something on this from Carol Shelby on a bead blasted surface in an inlet manifold, all interesting stuff.
Mike