JPH048698A - Fluid straightening fin - Google Patents

Abstract

PURPOSE:To reduce fluid resistance and increase the speed of an object moving in a fluid and reduce fuel consumption by sticking a fin made of a flexible material to the rear end portion of the object, which end portion is oriented in the direction in which the object moves. CONSTITUTION:A directional rudder fin 3 of tongue-shaped cross section is formed as part of a directional rudder 2 into an integral streamline and stucked along the rear end edge of the directional rudder 2 provided at the rear portion of a vertical tail 1. The directional rudder fin 3 is made of a carbon fiber excellent in weather resistance and of proper hardness and is stuck to the directional rudder 2 by means of adhesion, integral molding, bolts, calking or a combination of these methods. When the directional rudder 2 is inclined to change the direction of an aircraft, large fluid resistance is applied to the aircraft esp. on the directional rudder fin 3 at the rear end but the directional rudder fin 3 is bent along a main flow C as shown in Figure because of its elasticity and smoothes the air flow C whereby the fluid resistance is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a fluid rectifying fin that reduces fluid resistance of objects moving in fluid, such as the rudder of an aircraft or the rudder of a ship.

(Prior art) Objects that move in fluid, such as the main wings, ailerons, rudders, elevators, and propellers of aircraft, or the rudders and propellers of ships, change depending on the shape and speed of the object and the kinematic viscosity coefficient of the fluid. It is subject to fluid resistance depending on the Reynolds number.

In other words, as shown in Fig. 12, a boundary layer (B) is formed around an object (A) moving in the fluid, where the influence of the viscosity of the fluid appears intensively, and a layer of fluid is formed outside this boundary layer (B). A main stream (C) is generated whose viscosity is negligible.

This main flow (C) becomes a smooth laminar flow or a complicated turbulent flow depending on the situation, and the turbulent flow has a higher pressure than the laminar flow.

In addition, although the boundary layer (B) normally becomes a laminar flow, its thickness gradually increases toward the downstream side, and the Reynolds number, which changes depending on the velocity of the mainstream (C) and the thickness of the boundary layer (B), reaches a certain limit. When this value is reached, the boundary layer (B) becomes unstable and turns into turbulence.

This turbulent boundary layer occurs in the thick part of the layer on the downstream side, and as the shear stress increases, the turbulent boundary layer at this point finally separates from the object's surface, causing it to form near the rear end of the object. A separation region (D) is formed, and in this separation region (D), the fluid becomes a vortex, and cavitation occurs in the ship's propeller, increasing fluid resistance.

Particularly when an object in a fluid changes direction rapidly, a separation region is generated outside the direction change curve near the rear end of the object, generating a vortex flow and increasing fluid resistance.

Conventional objects moving in fluid have been formed into streamlined shapes to reduce fluid resistance, and have been constructed as rigid bodies made of metal, wood, etc., so as not to allow deformation.

(Problem to be solved by the invention) When blades, rudders, etc. move in a fluid, friction occurs between the surface of the object and the fluid, and the object is subject to fluid resistance. As mentioned above, there is a problem in that the fluid resistance becomes particularly large, leading to a decrease in the speed of aircraft and ships and an increase in fuel consumption.

It is an object of the present invention to provide a fluid rectifying fin that can alleviate the above-mentioned problems, reduce the resistance of objects moving in the fluid, speed up aircraft and ships, and save fuel. It is something to do.

(Means for Solving the Problems) To achieve the above object, this invention provides an aircraft wing,
It is fixed to the rear end of an object moving in fluid, such as a ship's rudder, in the direction of travel, and is made of an elastic material with appropriate hardness, and is formed into an integral streamline shape as part of the object. This is a fluid rectifying fin.

(Function) This rectifying fin made of an elastic material with moderate hardness is
The rear end of an object moving in a fluid, which is subject to particularly large fluid resistance, bends in the flow direction according to the magnitude of fluid resistance.The bending of the rectifier fins smooths the fluid flow and reduces fluid resistance. This can speed up aircraft and ships and save fuel.

(Embodiments) The present invention will be described in detail below based on embodiments shown in the drawings.

Figures 1 to 3 show an example in which the present invention is applied to the rudder of the vertical stabilizer of an airplane. The rudder fin (3) has a tongue-shaped cross section or is formed into an integral streamlined shape and fixed as part of the rudder (2).

This rudder fin (3) is made of carbon fiber that has excellent weather resistance and moderate hardness.
Fixation to the base is by adhesion, integral molding, bolting, caulking, or a combination of these.

When an airplane tries to change its direction, Figure 1 ■-■
When the rudder (2) is tilted as shown in Fig. 2, which shows an enlarged line cross-section, the rudder (2) is subjected to large fluid resistance, especially the rudder fin (3) at the rear end is subjected to strong resistance. Since the rudder fins (3) have elasticity, they can be bent along the flow of the main flow (CC) as shown in the figure, thereby smoothing the flow of the main flow (C) and reducing fluid resistance.

Figure 3 shows the case of a conventional rudder made of a rigid body. In this case, a vortex (4) is generated near the rear end of the rudder (2), which is subject to the greatest fluid resistance, resulting in large resistance. It is.

Although not shown in the drawings, air resistance can be similarly reduced by providing elevator fins on the elevator in the same way as the rudder fins (3) on the rudder (2).

Figures 4 to 8 show an example in which this invention is applied to a center boat (5) protruding from the bottom of a dinghy yacht. , a boat fin (6) having a tongue-shaped cross section and made of the same material as the rudder fin (3) is attached to the rudder (3).
It is stuck in the same way as in case 2).

At the heel of this dingy yacht, the centerboard (
When the boat fin (6) at the lower end is bent in the direction of flow, when the boat fin (6) at the lower end is bent in the flow direction as shown in FIG. This can reduce fluid resistance.

Figure 6 shows a conventional center hoard (5) made of a rigid body in the same state as in Figure 5. In this case, a vortex (4) is generated near the lower end, increasing fluid resistance, and the dinghy yacht This obstructs the navigation of the aircraft.

In addition, as shown in FIG. 7, which shows the cross section along the line IV-IV in FIG. 4,
Center board (5) when tacking a dinghy sailboat
) receives the main flow (C), the rear end of the boat fin (6), which has the highest resistance, bends in the flow direction in the same manner as described above, thereby reducing the fluid resistance at the rear end.

Figure 8 shows a conventional centerboard (5) made of a rigid body in the same state as Figure 7. In this case as well, a vortex (4) is generated near the rear end, increasing fluid resistance. , which interferes with the sailing of the dinghy yacht, similar to when the dinghy yacht heels as shown in FIG.

9 to 11 show other embodiments, and FIG. 9 shows a main wing fin (8) at the end of the main wing (7) of an airplane, and a board fin (6) in the center hoard (5).
In addition, an aileron fin (10) is provided along the trailing edge of the aileron (9) in the same manner as the rudder fin (3) in the rudder (2), and the main wing fin (8
) is the board fin (6) and the aileron fin (10).
These have the same functions and effects as the rudder fins (3) described above.

FIG. 10 shows a cross section of an example applied to a ship's rudder, in which a rudder fin (12) is fixed to the rear end of the rudder (11), similar to the rudder (2) above. When the rudder (11) is tilted to the left or right as shown by the imaginary line to change the course, the rudder fin (12) bends along the mainstream (C) to reduce fluid resistance, which is the same as on each side above. It is.

Fig. 11 shows a ship's screw (13) with screw fins (I4) fixed to the rear peripheral edge of the screw blade in the rotating direction, and the function and effect of this screw fin (14) are similar to those on each side above. It is.

In addition to the embodiments shown above, the fluid rectifying fins of the present invention can be applied to various objects moving in the air or water.

4° (Effect of the invention) According to the fluid rectifying fin according to the present invention described above,
By fixing a fin made of a flexible material to the rear end of an object moving in the fluid in the direction of movement, fluid resistance can be reduced, increasing speed and reducing fuel consumption. .

[Brief explanation of the drawing]

Fig. 1 is a side view showing an embodiment in which the present invention is applied to the rudder of an airplane, Fig. 2 is an enlarged sectional view taken along the line ■-■ in Fig. 1 showing a state in which the direction of travel is changed by tilting the rudder, and Fig. 3 2 is a cross-sectional view of a conventional rudder, FIG. 4 is a side view showing an embodiment of the present invention applied to the centerboard of a dinghy yacht, and FIG. 5 is a diagram showing the state of the centerboard when the dinghy yacht heels Fourth
Figure 6 is a cross-sectional view taken along the line I-m in Figure 6. Figure 6 is a cross-sectional view similar to Figure 5 with a conventional center hoard. Cross-sectional view FIG. 8 is a cross-sectional view similar to FIG. 7 using a conventional center hoard. Fig. 9 is a plan view showing an embodiment in which the present invention is applied to the main wing and ailerons of an airplane, Fig. 10 is a cross-sectional view showing an embodiment in which the present invention is applied to a ship's rudder, and Fig. 11 is a plan view showing an embodiment in which the present invention is applied to the rudder of a ship. FIG. 12 is an explanatory diagram showing the state of the fluid around the wing moving in the fluid. ■ Vertical stabilizer 2 Rudder 3 Rudder fin 4 Vortex 5 Center board 6 Port fin 7 Main wing 8 Main wing fin 9 Aileron IO Aileron fin 11・Rudder 12・・Rudder fin 13・・Screw 14・・Screw fin collection diagram

Claims (1)

[Claims] 1. A fluid rectifying fin, which is fixed to a rear end of an object moving in a fluid in the direction of movement, is made of an elastic material, and is integrally formed into a streamlined shape as a part of the object.