What is the difference between a hovercraft lift fan and a hovercraft propulsion fan?
I'm researching to build a hovercraft, and I am not sure what the difference is between a propulsion fan and lift fan. I can find a hovercraft propulsion fan that requires 19 hp, but an engine like that is too expensive. The hovercraft lift fan only requires 11.9 hp, and I can afford an engine like that. So I was wondering if I could just use the lift fan as a propulsion fan, if I ever decide to build a hovercraft. I understand the difference in the fans' functions, but what is the difference in the fan itself?
is it a different size, pitch or shape?
...All I really want to know is if I could replace the 'propulsion fan' with the 'lift fan'