Is the Toroidal Propeller the Greatest Prop Advance since the Wright Brothers?

These interestingly-shaped toroidal propellers may be a significant advance for both the aviation UAV and marine ROV sectors. An MIT student team found itself wondering whether prop noise in multirotors could be mitigated with differently-shaped propellers, and this extraordinary design was developed.  Much quieter than traditional propellers in air and water, they also demonstrate large efficiency gains. A key issue with airborne multicopters is annoying rotor noise, often described as "whiny”.  Drone applications in towns and cities are growing as municipalities introduce regulations facilitating low-altitude use by schools, medical services and schools. All agree that we don’t want more annoying noises flying overhead in urban or rural, or wild environments.

Private industry is proceeding with toroidal prop commercialization. Sharrow Marine has achieved amazing results from boat propellers that use toroidal loops instead of standard blades. The company has tested toroidal props against hundreds of standard propellers. Sharrow's props don't create tip vortices, a major source of energy loss and a major component of outboard engine noise. Hobbyists are now flying drones using toroidal propellers. Will toroidal props change the look and sound of aerial and maritime drones forever?