Coanda Effect Drone - Update

I wonder if you put lots of holes in the base of the impeller and in the dome below the impeller, whether there would be a toroidal circulation. High speed low momentum air flowing up through the centre and low speed high momentum flowing down on the outside. Cool drone btw, does it work any more efficiently when it is flying fast horizontally? It could be interesting to fly it down a gentle incline/hill. which way does one of those smoke-ring cannons move? In the direction of the air passing through the middle or around the outside?

tobias peers

An inverted drop shape could work! The theory behind the half sphere is that the air pressure above the dome is lower than the pressure below, therefore hopefully increasing the lift (by a very tiny amount). Thanks!

Tom Stanton

I've tried impellers with 3 blades and up to 10 blades, different AOA blades, different height blades and all seem to either produce too little thrust, or draw too much current, or both haha. I've done a few tests today and the drone can get off the ground, but it struggles to leave ground effect.

Tom Stanton

Would an inverted drop shape help ? instead of sort of half sphere . Wish you success

Dany Ravikovitch

I've seen demos of the coanda effect and it's supposed to be very efficient. Is the issue with the thing struggling simply the impellers are too small or have the wrong shape or number of blades? Good luck with the test flights, this looks cool!

U.S. Water Rockets

Smoke machine... Oh the possibilities!

Cheers mate :) That's a great idea, I have some white ribbon somewhere and just ordered a fog machine to hopefully visualise the flow

Tom Stanton

Yes they suck the air in through the middle. The only issue is the inefficiency of the impeller for drone use. Here is a guy that's tried/trying it: https://www.spartaninnovations.org/mohyi

Tom Stanton

Very cool dude :) wacky as always! one thing you could do for the video was a small thin bit of perspex/acrilit with the shape of the impeller and tomato cut out and fill it with little tell-tales. That way you could quite easily visualise the flow going into the impeller, out of the sides and down the tomato. Also depending on what you see you could be maybe a bit easier to estimate how inefficient it is

I assume the "propeller" suck in air from their middle? Would it be possible with this technique to build a drone that has no parts where you could hurt your finger just by adding a cage around the propellers?

Philip Brechler