Abstract: An all-speed-range propeller having stern fins comprises an all-speed-range propeller installed on a propelling shaft of a boat, and a plurality of stern fins installed between the all-speed-range propeller and a hull of the boat. When the all-speed-range propeller having stern fins is applied to the oblique boat on which the propelling shaft is disposed obliquely, the stern fins directly guide the water flow toward the all-speed-range propeller, so that the uneven inflow caused by the obliquely-designed propelling shaft can be conquered to promote the operating efficiency of the all-speed-range propeller.

Abstract: An all speed range propeller includes a propeller hub and plural propeller blades having their shafts symmetrically connected with the propeller hub. Each propeller blade is divided into a first region and a second region from the propeller hub to an outer end. The first region and the second region are different in wing structure, and the wing cross-sectional area of the second region is smaller than that of the first region. Thus, in speed ranges that common ships navigate most frequently, the all speed range propeller of this invention can lower the influence of cavitation produced because of different speed ranges, able to maintain high efficiency in use and prevent the efficiency of the propeller from lowered exceedingly.

Abstract: A design method of an all-speed propeller includes five steps; a first step (A) of creating a basic shape of an all-speed propeller, a second step (B) of optimization of circulation distribution, a third step (C) of adjusting the shape of the all-speed propeller, a fourth step (D) of analysis of thrust and torsion and fifth step (E) of finishing the design of the all-speed propeller. With parameters of a design request repeatedly processed by a lifting line program, a lifting surface program and a boundary element program in the steps mentioned previously, the all-speed propeller can lower cavitation effect caused by different speeds on the capacity of the propeller, so as to enable efficiency kept rather high without sharply lowering while navigating in diverse speeds.

Abstract: Advanced foil design method and structure for multi speeds mainly adds a constraint according to a needed pressure distribution of the advanced foil after building an advanced foil environment. Thence, a step of optimization could be applied for analyzing the advanced foil by flow characteristics to achieve a shaped profile, so that a weight calculation weighted calculation would be further operated base on a proportion of the advanced coil applied to multi speeds. Accordingly, a preferable profile of the advanced foil and the environment parameter combination can be obtained to enhance a higher operative efficiency with the preferred benefit of the Supercavitating propeller while applied to a higher speed and with the profit of a stable competence while applied to a lower speed.