What should I use for a hovercraft fan?

I have all the necessary building materials (wood, plastic tarp, foam, etc...) as well as a 22 hp engine and a weed whacker engine (both gasoline). I'm having trouble figuring out what i need in terms of a lifting fan. I've determined that i need something that can provide at least 4000cfm. I've looked at industrial shop fans 20+ inches in diameter which seem to provide enough airflow to work, but I've never seen them used in my research. Can anyone help?

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paulzer034 years ago

Try http://www.hoverhawk.com.
Their smallest fan, 22", pushes 8760cfm with a 5hp, 3600rpm motor and weighs... 5LBS!

gmxx8 years ago
for the fan that people use to hover, generally it is a shop vac set to blow. the shop fans you are looking at might be good for providing forward/back/left/right movement
Transience (author)  gmxx8 years ago
a shop vac can only provide about 1/10th of the airflow i need. Once fully loaded the craft will weigh in the area of 500lb, so using shop vacs or leaf blowers is not possible.
gmxx Transience8 years ago
https://www.instructables.com/id/Hovercraft/

have you seen that link?
would something like that work?
Transience (author)  gmxx8 years ago
Almost, on the last page the kid says that the thing wouldn't hover after he put the second engine on it. Of course his are less powerful than the one I've got.
gmxx Transience8 years ago
ok... what is the purpose of the hovercraft? what if you used two fans for vertical thrust?.... might let too much air out the top though.... Im really intrested in this now...
Transience (author)  gmxx8 years ago
recreational really, i'm looking at a 5x7 hull (maybe bigger). able to carry 2 or 3 people. I found a calculator that gave me a value of 4000cfm at 75ft/s for the airflow. Two fans might work, but again the problem is what to use?
Can you give a link to the calculator thing please?
frankenboom7 years ago
 The rpm these engines produce also matters. If the rpm is higher than the maximum rpm of the fan, the fan could fly apart, sending shards of metal everywhere. Also, which engine are you planning to use for the list?
As far as some of the fans on grainger, i dont see why they wouldnt work. 
theyre cheap enough (most of them ) that it wont be that bad if it doesnt work. You could also just fiddle around with the structure of the lift duct...
i dunno, just some ideas
 sorry, i meant lift not list
 also, what are you going to use for the propulsion? just curious.

Tommy W8 years ago
EI_Flyboy8 years ago
Whatever fan you use, don't forget about the "momentum curtain," it's the simplist most effective way to increase your lift:

http://www.jameshovercraft.co.uk/hover/html/hovercraft_concept_theory.htm
LIft fans are mainly centrifugal designs aren't they ? They work well into pressurised chambers. How fast do you expect to spin it, how good are you at metalwork ? Or can you get something in a scrap yard ?
Transience (author)  steveastrouk8 years ago
I was hoping to find something on the cheap, like at a scrap yard or craigslist, but I haven't been having much luck