Hello everyone. I am working on a VTOL RC craft that I hope will work. I was planning on using a centrifugal fan to accelerate air radially (instead of a squirrel-cage design), and putting 45 degree truncated cones around it to direct it downwards. I wrote a program with many small particles accelerating outward from a 'fan', and they bounced as predicted off the shrouds. I was just wondering if you think this would work in real life. I was thinking if the fan blades were at a pretty large distance and tall, it could move quite a bit of air. With a larger diameter, it wouldn't need to spin as quickly as a smaller unit. I was going to build this using a chainsaw engine to move two centrifugal fans (only one is shown in the drawings), and make truncated cones from plastic. I was wondering if anybody had any advice or input for this. I was also wondering if anyone knew any useful formulas to aid in the design process.