Propulsion device for ship

Abstract

A propulsion device for a ship is introduced. The propulsion device for the ship comprises a duct having a nose corresponding to the front vertex of a hydrofoil cross-section and a tail corresponding to the rear vertex of the hydrofoil cross-section, wherein the shape of the duct cross-section comprises: an outer surface formed upward in a convex shape at the front end of the duct and formed downward in a concave shape at the rear end of the duct; an inner front part of the duct formed downward in a convex shape at the front end of the duct; an inner rear part of the duct formed downward in a convex shape at the rear end of the duct; and a parallel part for connecting the inner forward part and the inner backward part in parallel to each other.

Description

technical field [0001] The present disclosure relates to a marine propulsion device, and more particularly, to a marine propulsion device capable of reducing vortices left around a hub by utilizing blades of different sizes having a duct section adapted to the characteristics of the flow within the duct. Background technique [0002] Increasing concerns about the maneuverability and propulsion efficiency of ships has led to an increasing interest in the main and auxiliary propulsion units provided in ships. For example, vessels such as drill ships are equipped with azimuth thrusters used to generate thrust for precise positioning or to tow other vessels during high or low speed voyages. [0003] There are two variants of azimuth thrusters based on the application, namely: open azimuth thrusters without ducts (such as propellers); and ducted azimuth thrusters with ducts, wherein the ducts have wings surrounding the ducted azimuth thrusters type section. [0004] The above-m...

AI Technical Summary

Problems solved by technology

While the above prior art documents achieve precise maneuverability and efficient traction, they do not provide an adequate description of the development of propulsion devices that provide higher propulsion efficiencies

[0010] In addition, the prior art only mentions outward flare and open angle, where the leading edge direction of the open angle is widened, without describing any technique for reducing the vortex generated by the propeller

Therefore, it may be difficult to absorb the rotational component of a propeller started in bollard conditions where only the propeller is rotating at the rated RPM when the vessel or vessel structure is nearly stationary

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