Hi Brian,

I did a quick test and it seems like this is fairly easy to do. The way I did it was use the program I created, PROP_DESIGN. I randomly used some inputs that I thought might work out. The first blade is swept back, the second swept forward. The other geometry characteristics are the same for each blade. By dumb luck, it seems to work out without any real issues. It also wouldn't have to be 'patented' like the MIT design. If they end up getting a patent for this, it's a real joke. This isn't any different than any other propeller, despite their claims. This capability has been in PROP_DESIGN for over a decade. The nice thing is no code changes are needed, since the tips don't end at the same point, like I originally thought.

Some performance items that would go against their 'grand' claims. Generally, sweep is not a good thing. Straight blades with a constant chord are usually best. Noise has nothing to do with the geometry they are changing. Noise is caused by pressure drops. The more the pressure drops, the more noise you have. Doubling the blade count will make comparisons virtually impossible. The propellers will be very different. The propeller with double the blade count will be at a much lower diameter, to meet the same power requirements. This will end up changing the rpm. So basically, it's a whole different design from the ground up. It's easy to say one prop is quieter than another. However, comparing two props that draw the same power, is the key. There are a lot of ways to deal with noise. I doubt this toroidal prop thing is the best method.

I'm really at a loss for how this is patent worthy. But the way the world is, they will probably get it.

Anthony

I made the geo in Rhino 5. My foray into MoI was a failure. The MoI step files don't work with Netgen. That killed the transition for me. However, I still like to follow the forum. It's a great community.

Edit; Updated the pictures, to reduce the file size. However, I can't seem to figure out how to get them inline.