The progress of propeller blades, relying only on the intuitive reasoning of experts, can no longer meet the needs of the development of ship technology. It needs scientists to make a complete explanation of its hydrodynamic characteristics, which will promote the development of propeller theory.

The performance of many mechanical devices has been widely used when it is not clear. But before people fully understand its physical laws and complete theoretical analysis, it is difficult for these devices to achieve their best performance.