A Method of Propelling with Many Whirlpools Used by Inland Birds

摘要

The whirlpools occurring in nature can be classified into largely three kinds: firstly a cylindrical whirlpool, secondly an inverted triangular whirlpool, and finally a funneled whirlpool. This study takes note of the usage of a whirlpool which has energy at the apex such as tornado. The problem of the current propeller is that it cannot restrain the occurrence of cavitation at high speed of revolution. So it was attempted to solve the problem of the existing propeller by imitating the movement of the wings of inland birds. It seems that the method of propelling by circulation of whirlpool is more effective than the existing method of propelling with the angle of attack of the propeller.