Airfoils

Airplane wings, helicopter blades and propellers are all airfoils, but they are designed differently because they have different functions.  The airfoils in the proof of concept prototype are not the same as airplane wings, helicopter blades or propellers because of their shape and angle of attack.

An airfoil has a zero angle of attack when the airflow is parallel to the chord as illustrated below.

The above illustration defines the terms "chord" and "camber".  The "span" is the length of the airfoil.

The airfoils in the proof of concept prototype shown below have zero angle of attack, a high aspect ratio and a high Lift to Drag ratio (L/D ratio).  The Lift force is perpendicular to the Drag force.

The airfoils in the proof of concept prototype have a constant zero angle of attack, and there will be more Lift at the outer radius than the inner radius, but that's OK.  Although the airfoils are not designed to be efficient propellers, they do act as propellers in that they propel the beam and shaft similar to propellers on airplanes.

If you'd like to hear more about airfoils and lift, watch the video below.