Ship rudder with concave and convex surface of different cross-sectional thickness

Abstract

The present invention discloses a ship rudder with a concave-convex surface having different cross-sectional thicknesses, characterized in that the basic profile of the cross-sectional area of ​​the ship rudder is composed of two airfoils of different thicknesses, and the chord lengths of the two airfoils of different thicknesses are the same. Compared with a common ship rudder, the present invention can increase the stall angle of the ship rudder, and increase the lift generated by the ship rudder at the same rudder angle, thereby improving the steering performance of the ship rudder. Under the same operating conditions, the concave-convex ship rudder can reduce the negative effects caused by cavitation of the ship rudder, and increase the service life of the ship rudder.

Description

Technical Field

[0001] The invention relates to the technical field of improving the steering performance of a ship rudder, in particular to a ship rudder with a concave and convex surface having different cross-sectional thicknesses. Background Art

[0002] With the development of science and technology, the design of ship rudders is also constantly changing. In recent years, there have been many studies on ship rudders at home and abroad, among which flap rudders (composed of the main wing and the tail wing) are more studied, mainly through design optimization to improve the efficiency of the rudder, and fishtail rudders, twisted rudders and raised guide rudders are also studied. Due to the characteristics of the ship rudder itself: there is flow separation (i.e. stall) during its actual operation, the hydrodynamic performance of the ship rudder will be greatly affected. Under the same conditions, although reducing the thickness of the ship rudder can increase the lift coefficient of the ship rudder, its corresponding stall angle will also be reduced, which is not conducive to the actual operation of the ship rudder. If the thickness is too large, the steering performance of the ship rudder will be reduced. Therefore, when selecting the ship rudder, various working conditions of the ship will be comprehensively considered to improve the steering performance of the rudder while avoiding the stall of the ship rudder as much as possible. Therefore, how to overcome or suppress the stall of the ship rudder and improve the lift coefficient of the ship rudder is a very meaningful topic. Summary of the invention

[0003] In view of the technical problems that the thickness of the basic profile of the ship rudder will affect the steering performance of the ship rudder, a concave-convex ship rudder with different cross-sectional thicknesses is proposed. The present invention designs the basic profile of the ship rudder into two airfoil structures with different thicknesses, namely a thick airfoil section and a thin airfoil section. When the concave-convex ship rudder is in operation, the flow state of water near its surface will change, so that the fluid remains attached to the suction surface of the concave-convex ship rudder. Therefore, the large separation vortex will be overcome or delayed due to the different cross-sectional thicknesses. This will increase the lift coefficient of the ship rudder and improve the steering performance of the ship rudder.

[0004] The technical solution adopted by the present invention is as follows: a ship rudder (1) with a concave and convex surface and different cross-sectional thicknesses, wherein the basic profile of the cross-sectional area of ​​the ship rudder is composed of two airfoil structures with different thicknesses.

[0005] The concave-convex surface ship rudder (1) comprises a thin airfoil section (2) and a thick airfoil section (3).

[0006] The thick airfoil section (3) and the thin airfoil section (2) have the same chord length, that is, the leading edge (4) and the trailing edge (5) of the formed concave-convex surface ship rudder (1) are straight lines.

[0007] The difference between the maximum thickness of the thick airfoil section (3) and the maximum thickness of the thin airfoil section (2) is greater than zero, that is, in the side view schematic diagram of the concave and convex surface ship rudder, the surface (6) of the ship rudder is a sine wave-like form rather than a straight line.

[0008] Due to the characteristics of the ship's rudder itself, it will produce flow separation and a large separation vortex during actual operation. The hydrodynamic performance of the ship's rudder will be greatly affected by the existence of the large separation vortex.

[0009] Compared with the conventional ship rudder, the concave-convex surface ship rudder of the present invention can increase the stall angle of the ship rudder, and increase the lift generated by the ship rudder at the same rudder angle, thereby improving the steering performance of the ship rudder. Under the same operating conditions, the concave-convex surface ship rudder can reduce the negative impact caused by cavitation of the ship rudder and increase the service life of the ship rudder. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art description are briefly introduced below. The drawings described below are an embodiment of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor.

[0011] Figure 1 It is a schematic structural diagram of the concave-convex surface ship rudder of the present invention.

[0012] Figure 2 It is a front view schematic diagram of the concave-convex surface ship rudder of the present invention.

[0013] Figure 3 It is a side view schematic diagram of the concave-convex surface ship rudder of the present invention.

[0014] Figure 4 It is a top view schematic diagram of the concave-convex surface ship rudder of the present invention.

[0015] Among them, 1 is a concave-convex ship rudder, 2 is a thin airfoil section, 3 is a thick airfoil section, 4 is a leading edge, 5 is a following edge, and 6 is the surface of the ship rudder. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0017] like Figure 1As shown, one embodiment of the present invention provides a concave-convex ship rudder (1) with different cross-sectional thicknesses, which comprises: a thin airfoil section (2), a thick airfoil section (3), a leading edge (4) and a following edge (5).

[0018] like Figure 2 As shown, the leading edge (4) and the trailing edge (5) of the concave-convex surface ship rudder are in the form of straight lines.

[0019] like Figure 3 As shown, the thin airfoil section (2) and the thick airfoil section (3) of the concave-convex ship rudder have different maximum thicknesses. The thin airfoil section (2) and the thick airfoil section (3) are alternately present at equal intervals in the span direction and are sequentially connected by B-spline surfaces to form a surface (6) of the ship rudder. The surface (6) appears as a sine wave in the side view schematic diagram, while the surface of a traditional ship rudder appears as a straight line in the side view schematic diagram.

[0020] like Figure 4 As shown, the thin airfoil section (2) and the thick airfoil section (3) have certain differences in coordinate points except that they overlap at the leftmost side (leading edge) and the rightmost side (following edge).

[0021] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, the technical solution described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. These modifications or replacements will not cause the essence of the corresponding technical solution to deviate from the scope of the technical solution of the present invention.

Claims

1. A ship rudder (1) with a concave and convex surface having different cross-sectional thicknesses, characterized in that: The basic profile of a ship's rudder cross section consists of two airfoil structures of different thickness; The concave-convex surface ship rudder (1) comprises a thin airfoil section (2) and a thick airfoil section (3); The thick airfoil section (3) and the thin airfoil section (2) have equal chord lengths, that is, the leading edge (4) and the trailing edge (5) of the formed concave-convex surface ship rudder (1) are straight lines; The difference between the maximum thickness of the thick airfoil section (3) and the maximum thickness of the thin airfoil section (2) is greater than zero, that is, in the side view schematic diagram of the concave and convex surface ship rudder, the surface (6) of the ship rudder is a sine wave-like form rather than a straight line.

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