KR20140004402A

KR20140004402A - Propeller wings with wavy leading edge

Info

Publication number: KR20140004402A
Application number: KR1020120071907A
Authority: KR
Inventors: 이진욱; 장봉준
Original assignee: 현대중공업 주식회사
Priority date: 2012-07-02
Filing date: 2012-07-02
Publication date: 2014-01-13

Abstract

The present invention relates to a propeller wing for propelling a ship, whose leading edge is formed in a wavy shape in order to improve propelling efficiency and to reduce the generation of cavitation. The propeller wing prepared by the present invention is a wing (20) which is formed on the outer circumference of a hub (10). In the outline of the wing generated when the wing (20) is projected on a flat surface at a right angle to a central shaft in a direction facing the central shaft of the hub (10), the leading edge which cleaves a fluid at the initial stage of rotation is formed in the curved shape of multiple waves (30).

Description

Propeller wing with wave leading edge {Propeller Wings With Wavy Leading Edge}

The present invention relates to a propeller blade for ship propulsion, and more particularly, to a propeller blade having a leading edge of a waveform to configure the leading blade of the propeller blade into a waveform to improve the propulsion efficiency and to reduce the occurrence of cavitation. will be.

The propeller of the ship is installed at the rear lower part of the ship to generate the propulsion force by rotating the wing under the power of the engine.

The propeller is formed in the form of a plurality of wings on the outer periphery of the hub (hub), which is the central axis, the plurality of wings form a predetermined angle of attack (twist angle) with respect to the center axis of the hub cross section, By giving the shape characteristic which changed the angle of attack and cross-sectional size from the root part to the radial tip part, the thrust force is obtained by pushing a fluid back by rotation of a blade (for example, refer patent documents 1-6).

The propeller is in direct contact with the fluid to obtain the propulsive force, the flow of the fluid is induced, and the cavitation caused by the fluctuations in pressure of the fluid and variables such as lift and drag due to the flow and friction of the fluid Since the same problems arise, the propeller's wings must be designed with the optimal shape to effectively respond to these factors. For example, the propulsion efficiency is greater than the drag, so the propulsion efficiency is large. On the other hand, if the lift force acts on the propeller blades and the cavitation occurs excessively, the erosion surface erosion is installed on the propeller blades as well as the propeller blades. Induces unpleasant noise and vibration.

In the propeller for ships, as can be seen in the patent literature, when the propeller blade rotates, the fluid flows along the surface of the blade and is released at the rear end of the tip part of the blade, thereby generating a vortex and a sudden change. Bubbles are generated by the pressure drop. In addition, even in a portion adjacent to the hub, bubbles are generated while generating a vortex due to a large angle of attack and a pressure change caused by a change in the fluid passage area. These vortices and bubbles (cavitation) reduce the lifting force acting on the propeller blades, lowering the propulsion force and generating noise due to the bubbles being destroyed (destruction), and bubbles adhere to the surface of the propeller blades or the surface of the rudder. Alternatively, the surface erosion of the propeller blades or the rudder may be caused by the impact of the adjacent fracture.

In order to solve these problems, various conventional examples are disclosed in Patent Documents 1 to 6, and various types of research have been conducted to explore the best and optimal forms for propeller blades.

Korean Laid-Open Patent Publication No. 2002-0061809 (2002.07.25) Registered Patent Publication No. 10-0404027 (2003.11.01) Registered Patent Publication No. 10-0394486 (2003.08.09) Korean Laid-Open Patent Publication No. 10-2012-0008312 (2012.01.30) Utility Model Registration Registration No. 20-0406520 (January 23, 2006) Registration Utility Model Publication No. 20-0406519 (January 23, 2006)

As one of the various studies, the object of the present invention is to propose another effective method for constructing the leading blade of the propeller blade into a waveform to improve the propulsion efficiency and to reduce the occurrence of cavitation.

The above object of the present invention is a wing formed on the outer periphery of the hub, which is preceded in the rotational direction among the wing contours generated when the wing is projected on a plane perpendicular to the center axis in a direction facing the center axis of the hub in front. By providing a propeller blade characterized in that the leading blade separating the fluid is bent into a plurality of waveforms.

According to an embodiment of the present invention, the plurality of waveforms may be configured such that the wavelength WL gradually increases from the root of the wing to the tip while maintaining the same wave height WH throughout the wing.

Alternatively, the plurality of waveforms may be configured such that the wave height (WH) gradually decreases from the root portion of the wing to the tip portion.

Alternatively, the plurality of waveforms may be configured such that the wave height (WH) gradually decreases and the wavelength (WL) gradually increases from the root portion of the wing to the tip portion.

In another embodiment of the present invention, the plurality of waveforms, the virtual outline (OC) forming the outermost part of the leading blade, and the virtual to maintain a distance of the wave height (WH) relative to the outline (OC) Draw a medial line (IC), and draw a plurality of concentric circles at equal intervals radially outward from the center of the hub, so that the intersection point where the outer line (OC) and the medial line (IC) meets the concentric circles, the top and valleys of the waveform It can be formed in the form of alternately connected as possible.

In still another embodiment of the present invention, the plurality of waveforms, the virtual outline (OC) forming the outermost part of the leading blade, and the virtual to maintain a distance of the wave height (WH) with respect to the outline (OC) Draw an inner line (IC) of the, and draw a plurality of concentric circles that gradually increases toward the radially outward from the center of the hub, so that the intersections of the outline (OC) and the inner line (IC) with the concentric circles of the waveform It may be formed in a form in which the top portion and the bone portion alternately connected.

According to the propeller blade of the present invention, by forming the leading blade of the blade in a curved form by a plurality of waveforms, it is possible to improve the propulsion efficiency, suppress the occurrence of cavitation, so that the propeller blade can reduce the erosion and noise of the steering wheel of the rear part have.

Moreover, when the shape effect of a wave shape is enlarged in the vicinity of the root of a wing | blade, generation | occurrence | production of the cavitation can be suppressed effectively in the vicinity of the hub with a large angle of attack.

1 is a view showing a general propeller wing viewed from the front of the central axis of the hub.
Figure 2 is a view showing the propeller blades according to the present invention.
3 is a view showing various examples of the propeller blades according to the present invention.
It is a figure explaining an example of the waveform formation method of the propeller blade which concerns on this invention.
It is a figure explaining an example of the waveform formation method of the propeller blade which concerns on this invention.
6 is a view showing another configuration example of the waveform of the propeller blades according to the present invention.
7 is a view showing various modifications of the propeller blades formed by the method shown in FIG.

EMBODIMENT OF THE INVENTION Hereinafter, the Example of this invention is described concretely, referring an accompanying drawing.

1 is a view showing a general propeller blade viewed from the center axis of the hub to the front before explaining the present invention.

As shown in Figure 1, the blade 20 is formed on the outer periphery of the hub 10, the hub 10 is a portion that is connected to the rotating shaft connected to the engine of the ship rotates.

On the outer circumference of the hub 10, a plurality of wings 20 are formed radially. The blade 20 is disposed to form a predetermined angle of attack (twist angle) with respect to the central axis of the hub 10, the angle of attack and cross-sectional size is changed from the root portion of the blade 20 toward the radially outer side (tip). (See Patent Documents 1 to 6).

One wing 20 is rotated following the leading edge and the leading edge where the contour when viewed from the front of the central axis of the hub 10 is a front edge portion that first screens the fluid in the rotational direction. And a trailing edge, which is the rear edge portion at which the fluid exits, and a tip part, which is the radially top portion between the preceding blade and the trailing blade.

Figure 2 is a view showing the propeller blades according to the present invention.

As shown in FIG. 2, when the wing 20 is projected on the plane perpendicular to the central axis in the direction facing the central axis of the hub 10 (in the same direction as shown in FIG. 1), Among the contours of the blade 20, the leading blades are curved in a plurality of waveforms 30.

Thus, by forming the leading blade in a curved form by a plurality of waveforms 30, flow seperation is induced by the top of the waveform 30, so that the leading blade is compared to the blade of the smooth shape Suppresses the occurrence of cavitation by advancing the peeling point, thereby reducing friction problems caused by the fluid flowing past the leading edge directly adhering to the wing surface, and also by suppressing the vortex at the trailing edge, while reducing the pressure gradient Instead of reducing drag, lift can be increased to increase propulsion efficiency.

According to the present invention, the effect of the waveform 30 in the vicinity of the root of the wing 20 is configured relatively large. In other words, since the root portion of the wing 20 has a relatively large angle of attack, the vortex is severely generated and the pressure gradient is large, which is likely to cause hub cavitation. Therefore, the cavitation generation and drag can be reduced by suppressing the vortex and reducing the pressure gradient by relatively increasing the wave effect near the root portion.

To this end, the plurality of waveforms 30, from the blade root of the blade 20 toward the tip, while maintaining the same wave height WH (see FIGS. 4 and 5) throughout the blade 20. The wavelength WL (see FIG. 5) may be configured to increase gradually.

Alternatively, the plurality of waveforms 30 may be configured in such a manner that the wave height WH gradually decreases from the root portion of the blade 20 to the tip portion.

Alternatively, the plurality of waveforms 30 may be configured such that the wave height WH gradually decreases and the wavelength WL gradually increases from the root portion of the wing 20 to the tip portion.

3 is a view showing various examples of the propeller blades according to the present invention. In the description of the invention illustrated in FIG. 3, the chord length refers to the distance between the leading and following blades on the cross section of the blade 20 (used when defining the blade cross section in the field of ship propellers). See Patent Documents 1 to 5, etc.).

FIG. 3A shows a smooth leading edge that does not form a waveform on the leading edge, and FIGS. 3A to 3H vary the wave height WH of the waveform 30 with respect to the cord length of the wing. The configuration example is shown. According to Figure 3, the wave height (WH) of the waveform 30 to 0.5% to 3.5% of the code length (not limited to this, but can be any longer) in accordance with the characteristics of the ship, the size or number of wings, the number of revolutions, etc. The change in the waveform to be given can be seen. As shown in (b) to (a) in FIG. 3, the waveform effect is configured in a form of high.

4 and 5 are views showing a method of forming a waveform of the propeller blade described in FIG. The wave height (WH) ratio of the waveform shown in FIG. 5 (about 2.5% wave length of the cord length) is higher than that of FIG. 4 (about 1% wave length of the cord length).

This draws an imaginary outline OC that forms the outermost part of the leading blade on the wing 20 and maintains an interval as far as WH, i.e., a ratio of the code length, with respect to the outline OC. After drawing the inner line IC, the top line of the waveform 30 is formed on the outer line OC and the valley portion of the waveform 30 is formed on the inner line IC so as to be connected at an appropriate wavelength WL. . In addition, the portion adjacent to the root of the wing 20 has a shape in which the wavelength WL is small and the wavelength WL is longer as the tip portion is formed.

6 shows another method of forming a waveform, which can easily form a waveform 30 to increase the effect of the waveform of the portion adjacent to the root of the wing and to reduce the effect of the waveform toward the tip. The method is shown.

Referring to FIG. 6, a virtual outline OC forming the outermost part of the preceding blade is drawn, and a virtual inner line IC maintaining a distance as far as the wave height WH with respect to the outline OC is drawn.

Subsequently, a plurality of concentric circles 32 are drawn at equal intervals radially outward from the center of the hub 10 so that the intersections of the outline OC and the inner line IC with the concentric circles 32 are aligned with the top of the waveform. Alternately connect the bones to form.

Then, since the leading edge of the blade 20 is formed in the form of the slope of the curve becomes larger from the root portion to the tip portion, since the interval (that is, the wavelength) between the intersection points becomes wider when drawing the concentric circles at equal intervals, Naturally, it is easy to form a waveform in which the effect of the waveform 30 of the root portion of the wing 20 is large (the wavelength WL is shorter than the same wave height WH) and the effect of the waveform 30 decreases toward the tip portion.

Alternatively, although not shown in the drawings, the plurality of concentric circles 32 shown in FIG. 6 are drawn such that the interval gradually widens from the center of the hub 10 toward the radially outer side, and then the outline OC and the inner line It is also possible to alternately connect the points where the (IC) and the concentric circles 32 meet so as to be the top and the valley of the waveform.

FIG. 7 is a view showing a modified example formed by varying the number of waveforms by the method shown in FIG. 6.

In the blade shown in Fig. 7, (a) of Figure 7 is a blade having a smooth leading edge without forming a waveform, Figure 7 (b) is a form of three waveforms, ) Shows five waveforms, and FIG. 7 (d) shows seven waveforms.

The number of waveforms is formed by selecting an appropriate number according to the characteristics of the ship, the size or number of the wings, the number of revolutions, and the like.

The foregoing is a description of certain preferred embodiments of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, .

10: Hub
20: wings
30: waveform
WH: Digging
WL: Wavelength

Claims

As the blade 20 formed on the outer circumference of the hub 10,
Among the wing contours generated when the wing 20 is projected on a plane perpendicular to the center axis in the direction of looking toward the center axis of the hub 10 in front, a plurality of waveforms of the leading blades that divide the fluid in advance in the rotational direction ( Propeller blades, characterized in that formed by bending 30).

The method of claim 1,
The plurality of waveforms 30, propeller blades, characterized in that the wavelength (WL) gradually increases from the root portion of the blade 20 to the tip portion while maintaining the same height (WH) throughout the blade (20).

The method of claim 1,
The plurality of corrugations 30, propeller blades, characterized in that the digging (WH) gradually decreases from the root portion of the wing 20 to the tip portion.

The method of claim 1,
The plurality of waveforms 30, propeller blades characterized in that the wave height (WH) gradually decreases and the wavelength (WL) gradually increases from the root portion of the wing 20 to the tip portion.

The method of claim 1,
The plurality of waveforms 30,
Draw a virtual outline OC forming the outermost part of the leading blade, and draw a virtual inner line IC that maintains a distance as far as the wave height WH with respect to the outline OC, and the center of the hub 10. By drawing a plurality of concentric circles 32 at equal intervals radially outward from the, by forming the intersections of the outer line (OC) and the inner line (IC) and the concentric circles 32 alternately connected so that the top and valleys of the waveform Propeller wing characterized in that.

The method of claim 1,
The plurality of waveforms 30,
Draw a virtual outline OC forming the outermost part of the leading blade, and draw a virtual inner line IC that maintains a distance as far as the wave height WH with respect to the outline OC, and the center of the hub 10. By drawing a plurality of concentric circles 32 gradually widening toward the radially outward from the, the intersections of the outer line (OC) and the inner line (IC) meets the concentric circles 32 alternately so that the top and valleys of the waveform Propeller blades characterized in that formed by connecting.