How do I calculate the air pressure a motorized fan can generate using power of motor and dimensions of fan?

Question

I'm building a small hovercraft with an electric motor fan and I would like to know if I can calculate the amount of pressure the motor fan can generate to be sure the pressure is enough to lift the craft and one passenger. Basically I'm asking how to calculate the pressure generated by the fan based on the information of the motor such as the motor power (in horsepower or volts and revolutions per minute) and the fan dimensions. I also have to figure in the dimensions of the skirt and the holes from which the air is escaping from the skirt. I appreciate any help, thank you!

Answer 1

You need more than the motor power.

You need the fans characteristics.

Just as any airplane wing will stall at a given angle of attack at a given speed, a fan blade will stall at a given back-pressure at a given speed,

regardless of the power available.

Fan makers publish the pressure characteristics of their fans.

For your hover-craft, the limiting pressure will be the gross weight of the vehicle divided by its 'footprint area.

Answer 2

There are several characteristics which must be understood for your design. The CFM, cubic feet per minute is one of them.

Review the attached Fan design cookbook to determine what will best work for you.

As for the skirt, a rubber-cloth material like that of a rain suit works well for elasticity and strength. The bottom edge should be reinforced with a non-elastic rope or cord. For forward motion, a separate blower should be used.

For kits which you can consider check out the attached link.