Twin engine concept, evolved from the single engine concept

Here is what I lofted today in the iRhino:

To make reasonable place for the rear seat/seats, the wing position had to be moved lowish position. The feet of the rear passengers are below the wing spar of the wing.
The rear window is not necessarily in the best place, it might be too much forward. The idea is that the rear seat ends before the prop arc.

The single engine idea in the previous post had apparent CG issues, how to get CG to correct position other than moving the prop completely on top of the fuselage, which moved the engine pod very high. This twin engine version which places the engine pods to the wings, solves this issue obviously.

Here is how it was drawn (in the case someone is interested in learning iRhino):
– The engine pod is NACA 66-025. It is lofted from couple of cross sections which were set along a helper-line which had the airfoil contour.
– The Fuselage is lofted from 5 elliptical cross sections
– The wings are lofted from two airfoil cross sections each
– The tail surfaces are lofted from two airfoil cross sections each
– The canopy and window utilize the Project to Surface -function of the iRhino
– The picture is drawn with correct dimensions. I used measurement -lines to make the parts correct size. The grid was set to 10 cm spacing.

The fuselage height is 86 cm, length is 6.6 meters. I have not yet measured if one can fit inside or not. But basically it resembles a sail plane fuselage. The fuselage may require some scaling up to fit more than two persons inside.

    • ant1ant1
    • October 10th, 2008

    Beautiful plane Karoliina! Really very graceful. I love the high aspect ratio surfaces.

    I have two ideas for you.
    In order to make people “fit” in my designs what I did was model front and rear passengers out of standard “humans”.
    Rear passengers have their legs bent as opposed to the almost stretched legs upfront.
    This makes for a painful but useful reality check….

    In order to solve CG problems I use a three lifting surface design. The front canard adds lift in all but pilot-only loading cases. This pulls the center of lift forward and allows for a forward CG to be OK.
    I will “soon” post my first attempt at a plane model in Blender on my blog here. Right now, I’m struggling with cutting canopied out of a wire frame and making them transparent (so one can see my PAX ūüôā

    Take care


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