JPS58126288A - Propeller for ship - Google Patents

Abstract

PURPOSE:To increase the propelling force by providing small blades at each blade tip to obtain a lift by the blade tip eddy generated by the rotation of a propeller and arranging a rectifying ring in front of blades to accelerate and equalize the flow to small blades. CONSTITUTION:When each blade 12 of a propeller 11 is rotated, a lift L is generated on the blade face to obtain a proplling force T and a revolution torque Q. Furthermore, due to the mutual interference between the lift L and a rectifying ring 15 to enclose the outside of the revolution locus of each small blade 13 and 14, a propelling force is generated on this rectifying ring 15 to accelerate this flow. At this moment, a flow speed U works on the tip parts of the blades 12 and a flow U1 goes from the front part of each blade 12 around to the backsides and generates a lift l by working on small blades 13 and 14 with a fixed angle of incidence for obtaining a propelling force (t) for each small blade 12 and an oppositely revolving torque (q) as its component force. Thereby, the propelling force is increased by (t) and the revolution torque is decreased by (q). This construction permits to increase the propelling force, and simultaneously prevent the cavitation caused by the blade tip eddy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a marine propulsion device, and more particularly to a propulsion device that combines a propeller with small blades and a rectifying ring.

In order to convert the output of the main engine into propulsive force most efficiently, propellers, which are generally installed on ships, require theoretical calculations and model tests on the area and cross-sectional shape of the blades that form the propeller. The results are now being effectively utilized in propeller design.

Here, the front and cross-section of a conventional propeller are shown in Figure 1 (a).
, (b) As indicated by K, such professional propulsion performance could not necessarily be expected to be satisfactory in the following respects. That is, 1. In each of these figures, when the propeller 1 rotates in the direction shown by the arrow M and the ship moves in the direction shown by the arrow BK, a vortex flows from the tip of each member 2 forming the putapet 1. , a so-called blade tip vortex 3 is released.

This wing tip vortex 3 flows from the front side of each member 2, beyond its tip, to the rear @4! in the direction of travel of the ship. This is a flow that swirls on the back side), and the pressure decreases at the center of this vortex 3, causing cavitation. This cavitation occurs because the propeller 1 rotates in the stagnation behind the ship, so its angle of attack is large and the pressure distribution on the back surface is reduced. The distribution is observed as shown in .

Therefore, in this conventional propeller 1, the blade tip vortex 3 and cavitation 4 not only reduce the propulsion force itself, but also cause the blade surface to be eroded by the impact when the generated bubbles disappear. As a result, the smoothness of the wing surface is lost, resulting in even worse propulsion efficiency, which can eventually lead to damage to the wing itself, and cavitation.
The stern vibration associated with the zero-extinction cycle was a problem.

In addition, to solve this problem with conventional propellers, a small blade is installed at the tip of each member that generates lift by a blade tip vortex, and a propulsive force as a component of this lift and negative rotational torque are obtained. There are also propellers with small blades that are designed to increase propulsive force and prevent cavitation, but even with these propellers with small blades, if they rotate in stagnation at the rear of the ship, they may cause uneven stagnation. Because of this, the angle of attack of the flow flowing into the winglet changes greatly during one revolution of the propeller, making it impossible to take full advantage of the effect of the winglet.

In view of the shortcomings of conventional propellers, this invention combines a propeller with small blades with a rectifying ring, and the rectifying ring relaxes the unrestrained flow of the flow flowing into the propeller with small blades. It is a companion that maximizes the effect of the small wings.

Hereinafter, embodiments of the propulsion device according to the invention will be described in detail with reference to FIGS. 3 to 13.

3 and 4 (-9) are a perspective view, a partial front view, and a sectional view of the first embodiment, and FIG. 6 is an explanatory view of the same operation. In each of these figures, the propeller 911 has a plurality of blades 12 and is rotated in the direction shown by arrow C. A small wing 1s protruding in the direction of ship O shown in
and wings 12 and 70 in opposite directions adjacent to this winglet 13.
The winglets 14 are integrally provided at an angle of ~160°. Also, each small wing 13 is located on the front side of the propeller 11.
, 14 so as to surround the outside of the rotation locus of the rectifying ring 15.
is installed.

Therefore, in this first embodiment, when each blade 12 of the propeller 110 rotates in the direction of arrow C, a lift force is generated due to its true shape, and a propulsive force T and rotational torque Q are obtained as the -components of the lift force. The mutual interference between the lifting force and the rectifying ring 15 generates a propulsive force in the rectifying ring 15, and the rectifying ring 15
Accelerate the flow within. At this time, a flow velocity indicated by the symbol U acts on the tip of the blade 12, and the flow Ul having this flow velocity Ut is as follows:
mb from the front side of each member 12 to the back side, each small wing 13.
14 at the desired angle of attack, and therefore each winglet 13, 14 has a flow υ! A lift force t perpendicular to is generated, and as its component force, a propulsive force t for each member 12 and a rotational torque q in the opposite direction opposite to the rotational torque QK are obtained. As a result, the propulsion force T specific to each member 12 is t
The rotational torque Q will decrease by q.

In addition, Fig. 6 and Fig. 7 (2), 弽) correspond to Fig. 21 shown in Fig. 3 and Fig. 4 (a), (b) K.
11! FIG. 2 is a perspective view, a partial front view, and a sectional view of the embodiment. In this second embodiment, at the tip of each member 12 of the propeller 11 rotating in the direction of the arrow C described above, one small blade 14 is missing and a small blade 16 similar to the small blade 13 is installed. Representing the angle θ of °-160°, the ship's traveling direction DK
This is a structure that protrudes toward the front. Furthermore, Fig. 8, above, No. 7
Figure + b) A partial sectional view of the third embodiment shown corresponding to K.
In this third embodiment, the small wings 18 and 14 are provided to protrude in opposite directions.

The propeller with a single small blade in the second rear embodiment functions in the same manner as the small blade 13 in the first rear embodiment, and riIJ
There are many ways to achieve similar effects. In the propeller with two small blades in the third embodiment, the small blade 1B in the first embodiment,
Although the positional relationship of 14 is reversed, the effect appears to be almost the same.

In each of the embodiments described above, the rectifying ring 15 disposed in front of the propeller with small linear blades is of an axially symmetrical type, but from the viewpoint of bringing out this effect and coordinating with the stern shape, the rectifying ring 15 is shown in Fig. 9. ~ As shown in Fig. 35, the shape of the rectifying ring 15 and the combination of the positional relationship between the small-winged fishing rod 1 and the rectifying ring 1s are applied. Furthermore, the example shown in FIGS. 36 and 37 is also used for the positional relationship between the stern end 17 and the rectifying ring 15. Generally, a vertically asymmetric rectifying ring with a long upper part and a short lower part is often used.

Here, the results of an experiment 71j conducted in order to confirm the effects of the propeller with small blades 11 and the rectifying ring 15 in each of the above embodiments will be described.

First of all, Figure 38 shows the 1. Kifu with small wings 2 crests in the third embodiment
Fig. 511 is an explanatory diagram comparing and showing the relationship between the lift-drag ratio and the angle of attack in the propeller 1 in the conventional example, and the lift-drag ratio is obtained by measuring the lift force and drag force of X12 in Ift with a 3-component force meter. The vertical axis represents the lift-drag ratio, and the horizontal axis represents the angle of attack. The solid line R1 represents the propeller of the first embodiment, and the chain #R2 represents the propeller of the third embodiment.

Break #R8 indicates each value of the conventional propeller.

That is, as is clear from FIG. 38, it can be seen that the performance of the propeller 11 according to each embodiment is superior to that of the conventional propeller 1, mainly at the angle of attack α0.

Also, Figure 39 shows the small wings 13 and 14 for the wing surface of each member 12.
It is an explanatory diagram showing a change in the ratio of the lift-drag ratio Rθ divided by R3 when the protrusion angle θ is varied, and the vertical axis shows the lift-drag ratio,
The angle θ is plotted on the horizontal axis, and it can be seen from FIG. 39 that the effective range of the angle θ is 70° to 160°.

Next, FIGS. 40 and 41 are the values shown in FIG. 7).

It is an explanatory diagram showing a developed view of each of the winglets 13 and 14 in the wing 12 shown in (b), and the ratio of the vertical and horizontal dimensions ts and tc of one winglet 13, ie, the relationship between the so-called aspect ratio and lift-drag ratio. Here, the aspect ratio of the other winglet 14 is assumed to be constant, and the vertical axis is the lift-drag ratio, and the horizontal axis is the aspect ratio. From this Fig. 41, the larger the aspect ratio of the winglet 13, the higher the lift-drag ratio It can be seen that it is effective to increase the size, but in this case, there is a limit due to strength and geometric constraints, so it is necessary to determine each individually when designing, and generally the range of M/ is 1 .0 to 5.0 is the practical tJa.

Furthermore, FIG. 42 shows a conventional propeller 1 and a small-blade propeller 11, and a small-blade propeller 11 according to the present invention. It is an explanatory diagram that compares and shows the performance of the propeller in combination with the rectifier ring 15, and is generally used to express the independent performance of the propeller. On the vertical axis, the independent efficiency ηa of the propeller, which is similarly derived from the following equation, or the independent efficiency of the entire rectifying ring system, 17 vow, is plotted. The propeller U with a solid line P-.

Pusonpe with small wings in this invention 211. A propulsion device formed by a combination of rectifier rings 15 is shown by a chain line P3.

Advance coefficient bow = 凰D Va...Water inflow speed N...Rotation speed of propeller 2 D...Propeller diameter When operating as a single propeller? ...Thrust coefficient KQ ...Torque coefficient = -1- /) N 2 D4! ...Thrust ρ...Density of water i q...Rotation of the propeller L Luk When operating as a propeller and rectifying ring system, KvW!
...Total thrust coefficient Tν ...Propeller thrust TD ...Commutated ring thrust q ...Propeller rotational torque As is clear from this Fig. 42, with small blades Prope 71
The propeller 1 has better performance alone than the conventional propeller 1, but when the rectifier ring 15 is combined with the propeller 11 with small blades, it can be even more effective near the propeller operating point on a normal ship. It is something.

In the above embodiment, the shape of the rectifying ring 15 is so-called symmetrical in that the upper and lower KII lengths are equal, but according to the findings of the inventors, the rectifying ring 15
It has been confirmed that the same effect can be obtained when the shape is made into a so-called vertically asymmetric type in which the upper length is large when viewed from the side and gradually decreases toward the lower part.

As detailed above, according to this invention, a propeller for a ship is provided with a small blade at the tip of each JI, and lift is obtained from the wing tip vortices that circulate from the front side to the back side when the propeller rotates. At the same time, a rectifier ring is combined to surround the front K of the propeller with small blades and the outside of the rotation trajectory of the small blade, and this rectifier ring accelerates the stagnation of the uneven flow at the stern. Since it is made uniform and the change in the angle of attack of the flow to the small blade is reduced, it is possible to effectively obtain the optimal propulsive force and negative rotational torque as the lift component of the small blade, and from this, the propulsive force of the propeller is can be more comfortable to wear than before,
In addition to significantly improving its independent performance, it also prevents the occurrence of cavitation due to blade tip vortices, prevents a decrease in efficiency or damage due to erosion of the blade surface and the inner surface of the straightening ring 15, and also prevents cavitation by suppressing cavitation. It has features such as being able to reduce stern vibration.

[Brief explanation of the drawing]

Figure 1 (-9 (6) and Figure 2-), 伽) is a front and cross-sectional view showing a conventional propeller and its cavity distribution; Chapter 5a
11 is a perspective view showing a first embodiment of a nine-propeller in which a propeller with small blades and a rectifying ring according to the present invention are combined; 9 partial pressure surface and sectional view; and action explanatory diagram; FIGS. 6 and 7;
, (roll) is a perspective view 9 partial pressure ■ and a sectional view showing the second rear embodiment of the same as above, FIG. 8 is a partial sectional view showing the third embodiment of the same as above,
Figures 9 to 35 are combination diagrams of the shape and positional relationship between the propeller with small blades and the straightening ring, Figures 36 and 37 are diagrams showing the positional relationship between the stern end and the straightening ring, and Figure 38. is an explanatory diagram showing the relationship between the angle of attack and the lift-drag ratio in a propeller, FIG. 39 is an explanatory diagram showing the relationship between the small blade angle of the propeller and the lift-drag ratio, FIG. The figure is an explanatory diagram showing the relationship between the 7 spectral ratio of the small wing and the lift-drag ratio, No. 42.
11d is an explanatory diagram showing the relationship between the advance coefficient and the independent efficiency in the case of a propeller with an excessive amount of small blades and a propeller with small blades, and a combination of a rectifying ring with a propeller with small blades. 11... Propeller with small wings, 12... Wings, 13
, 14, 1i --- small wing, l! --- Rectifier ring, 1T
...Stern end. Patent Applicant Mitsui Engineering & Shipbuilding Co., Ltd. Agent Masaki Yamakawa (1 person) ■ - Law 502 -

Claims (1)

[Claims] At the tip of each member that makes up the propeller, a small blade is installed that obtains lift from the tip vortex generated at the blade tip when the propeller rotates. A marine propulsion device characterized in that a rectifying ring is arranged in combination to surround the wing and accelerate and equalize the flow to the small blade.