Magnus effect - Fan wing Aircraft

What is Magnus effect?

The flow over a rotating cylinder can explain the Magnus effect better. The cylinder rotates in one direction. The flow gets high velocity in the upper half and hence less pressure. Bottom half is rotating in opposing fashion to the free stream air flow, hence air molecules going around the region gets less velocity and hence high pressure.

The high pressure goes to compensate   the less pressure, then lift gets produced. The theory of production of lift from the rotating cylinder is what known to be Magnus effect.

What is fan wing aircraft?

Please have a read on Bernoulli’s law for better understanding of answer.

Fan wing aircraft is the one which produces lift primarily from the rotation of cylinder located in the wing span. It works based on the Magnus effect.

The fan part rotates. The angular velocity of the fan accelerates the linear velocity of air molecules passing over top surface of the fan wing aerofoil. Thus in the top surface less pressure zone has been created.

The air going through the bottom of the aerofoil is not influenced by the angular velocity of the fan, thus the bottom facing less velocity and high pressure.

High pressure goes to compensate the less pressure, hence lift gets produced.

What is the difference between a conventional and fan wing?

A conventional wing can generate less amount of lift than a fan wing for the same input.

Short runway is enough to takeoff for fan wing aircraft.

Critical angle of attack is high for fan wing. To know what is critical angle of attack click here. That means we can go for higher angle of attack than a conventional wing since the air flow is forcibly attached over the aerofoil surface.

For the detailed difference refer the illustration given below. Click on the image to see the full size.