JP2829575B2 - Boundary layer separation suppression device for moving objects - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for controlling a boundary layer of a moving body, for example, a wing surface of an aircraft, to suppress separation of the moving body.

[0002]

2. Description of the Related Art Conventionally, in order to control the boundary layer of a moving body to suppress separation, for example, a leading edge flap, a trailing edge flap, a slat, or the like provided on an aircraft wing is mechanically driven. Energizing the layers was done. According to this, the maximum lift coefficient is increased, and the stall suppression angle is increased. In addition, the outlet is provided at the leading edge and trailing edge of the wing to apply energy to the boundary layer to blow off the separation area, and conversely, a small hole for suction is provided on the upper surface of the wing, and energy is reduced from this hole. The air flow in the boundary layer region was sucked.

[0003]

However, according to the method of mechanically driving the leading edge flap and the like as described above, there is a problem that the weight of the aircraft increases in addition to the complexity of the apparatus. In addition, maintenance and inspection require a great deal of labor. In addition, since power is used even in the case of using blow-out or suction, the apparatus becomes large and the weight increases.

An object of the present invention is to provide an apparatus for suppressing boundary layer separation of a moving object which does not require a particularly complicated structure and is lightweight.

[0005]

In order to achieve the above object, a boundary layer separation suppressing device for a moving object according to the present invention is provided on the inside of the surface of the moving object along the moving direction. It is polarized in a direction perpendicular to the direction and extends in the moving direction by an applied voltage with the front side as the positive electrode and the opposite side as the negative electrode, and conversely, the moving direction by the applied voltage with the front side as the negative electrode and the opposite side as the positive electrode. A first piezoelectric element that shrinks with respect to the first piezoelectric element, and is shrunk in the moving direction by an applied voltage that is polarized in the opposite direction to the first piezoelectric element and has the front side as a positive electrode and the opposite side as a negative electrode, and conversely, the front side as a negative electrode And a plurality of piezoelectric element groups consisting of a second piezoelectric element extending in the moving direction by an applied voltage having the opposite side as a positive electrode, and an odd-numbered piezoelectric element group from the rear side of the moving body among the plurality of piezoelectric element groups. First voltage supply means for supplying an AC voltage; A second voltage supply means for supplying an even-numbered piezoelectric element group from the rear side of the moving body of the piezoelectric element group with an AC voltage having a phase delayed from that of the AC voltage supplied by the first voltage supply means; A vibration absorber that is installed at the front end inside the surface of the device and absorbs wave energy generated on the surface and converts the energy into electric energy; and a load circuit that is connected to the vibration absorber and consumes electric energy. Features (Claim 1).

According to the first aspect of the present invention, a plurality of grooves extending perpendicular to the moving direction are provided on the surface of the moving body from the front side to the rear side of the surface (claim 2).

The apparatus for suppressing boundary layer separation of a moving object according to the present invention is provided at a rear end inside the surface of the moving object, is polarized in a direction perpendicular to the moving direction, has a positive electrode on the surface side, and has an opposite side. Elongation / shrinkage (elongation or shrinkage) in the moving direction by an applied voltage having a negative electrode, and conversely, shrinking in the moving direction by an applied voltage having a surface side as a negative electrode and the opposite side as a positive electrode /
A piezoelectric element that expands (shrinks or expands), a distortion converter that converts distortion that expands and contracts in the direction of movement of the piezoelectric element into distortion that expands and contracts in a direction perpendicular to the direction of movement, and a voltage that supplies an AC voltage to the piezoelectric element Supply means, a vibration absorber installed at the front end inside the surface of the moving body and absorbing the wave energy generated on the surface and converting the energy into electric energy, and a load circuit connected to the vibration absorber and consuming the electric energy (Claim 3).

According to a third aspect of the present invention, there is provided a vibration expansion device interposed between a piezoelectric element and a surface of a moving body for expanding and contracting the piezoelectric element and transmitting the expansion and contraction to the surface of the moving body. A vibration reduction device interposed between the surface of the moving body and the vibration generated on the surface of the moving body to be reduced and transmitted to the vibration absorber;
(Claim 4).

According to the first aspect of the present invention, an odd-numbered piezoelectric element group from the rear side of the moving body among a plurality of piezoelectric element groups composed of the first piezoelectric element and the second piezoelectric element which has been subjected to the polarization processing in the opposite direction. An AC voltage is supplied from the first voltage supply means to the element group, and an even-numbered piezoelectric element group from the rear side of the moving body is supplied with an AC voltage supplied from the second voltage supply means by the first voltage supply means. Since an AC voltage with a delayed phase is supplied,
The surface has the expansion / contraction of the first piezoelectric element and the contraction /
A bending vibration occurs with the extension, and this vibration proceeds to the front side of the moving body, but a standing wave having no directivity is generated by a reflected wave from the front end. Here, since the vibration absorber is installed at the front end inside the surface of the moving body, the wave energy of the reflected wave is converted into electric energy and consumed in the load circuit. Therefore, as a result, a traveling wave traveling toward the front side of the moving body is generated. With the generation of this traveling wave, elliptical motion occurs on the surface from the front side to the rear side of the moving object, and the fluid molecules in the contact area of the surface are dragged to the rear side by the force of the elliptical motion, and the high speed Fluidized to Thereby, separation of the boundary layer can be suppressed.

According to the second aspect of the present invention, a plurality of grooves extending perpendicular to the moving direction are provided on the surface of the moving body from the front side to the rear side of the surface, so that the surface is bent due to expansion and contraction of the piezoelectric element group. The amplitude of the vibration increases. Therefore, the force of the elliptical motion is increased, so that the separation can be further suppressed.

According to the third aspect of the present invention, when an AC voltage is supplied to the piezoelectric element from the voltage supply means, the piezoelectric element is converted to expand / contract in a direction perpendicular to the moving direction by the function of the distortion converting means. As a result, bending vibration is generated on the surface, and a standing wave is generated by the reflected wave from the front end, but the reflected wave is absorbed by the vibration absorber and the load circuit in the same manner as in the first aspect of the present invention. Since that energy is consumed, a traveling wave is generated which travels forward. Accordingly, an elliptical motion is generated from the front side to the rear side of the moving body on the surface, and the fluid molecules in the contact area of the surface are dragged to the rear side by the force of the elliptical motion, and are fluidized at high speed. Thereby, separation of the boundary layer can be suppressed.

According to the fourth aspect of the present invention, since the vibration expansion device is interposed between the piezoelectric element and the surface of the moving body, the expansion and contraction of the piezoelectric element may be small. Further, since the vibration reduction device is interposed between the vibration absorber and the surface of the moving body, the vibration absorber and the load circuit connected thereto may have a small capacity.

[0013]

Embodiments of the present invention will be described with reference to the drawings. (First Embodiment) FIG. 1 is a side view showing an outline of a configuration of a boundary layer separation suppressing device for a moving body according to a first embodiment of the present invention. An example in which the present invention is applied to an aircraft as a moving object will be described.

This apparatus for suppressing a boundary layer separation of a moving body includes a plurality of piezoelectric elements including a first piezoelectric element 1a and a second piezoelectric element 1b which are arranged inside a wing surface 10 of an aircraft along a moving direction of the aircraft. A first voltage supply for supplying an alternating voltage to the group 1 and the odd-numbered (1, 3, 5,...) Piezoelectric element groups from the rear side (left side in FIG. 1) of the plurality of piezoelectric element groups 1 A power source 2 functioning as a means, and the rest of the plurality of piezoelectric element groups, that is, an even number (2, 4,...) From the rear side of the aircraft
A power supply 3 functioning as a second voltage supply means for supplying an AC voltage to the third piezoelectric element group, a vibration absorber 4 installed at the front end inside the blade surface 10, and a load circuit 5 connected to the vibration absorber 4 It is composed of Note that an electrode plate 6 is mounted below the piezoelectric element group 1.

The first piezoelectric element 1a is polarized in a direction perpendicular to the moving direction (vertical direction in FIG. 1) with the side closer to the blade surface 10 as the positive electrode and the side farther from the blade surface 10 as the negative electrode. By applying a voltage with the wing surface 10 side as a positive electrode and the electrode plate 6 side opposite to the negative electrode as a negative electrode, it extends in the moving direction, and conversely, the wing surface 10 side as a negative electrode and the electrode plate side as a positive electrode By applying a voltage as described in the following, it shrinks in the moving direction. Conversely, the second
The piezoelectric element 1b is polarized in a direction opposite to that of the first piezoelectric element 1a, that is, with the side approaching the wing surface 10 as the negative electrode and the side away from the wing surface 10 as the positive electrode. Then, by applying a voltage with the negative electrode plate 6 on the opposite side to the moving direction, it shrinks in the moving direction, and conversely, moving by applying a voltage with the wing surface 10 as the negative electrode and the electrode plate side as the positive electrode. It extends in the direction.

The AC voltage supplied by the power supply 2 is a sine wave (Si
nωt), while the AC voltage supplied by the power supply 3 is a cosine wave (Cosωt), and the phase is delayed.

The vibration absorber 4 uses a Langevin type vibrator as a power generator. That is, the piezoelectric element 4a is sandwiched between metal plates 4b, which absorbs the wave energy generated on the wing surface 10 and converts it into electric energy, and the load circuit 5 connected to the vibration absorber 4 controls the vibration energy. It is designed to consume the converted electrical energy.

In the apparatus for suppressing boundary layer separation of a moving body having the above-described structure, when an AC voltage is supplied from the power supply 2 and the power supply 3 to the piezoelectric element group 1, the blade surface 10
As shown in FIG. 2, a traveling wave is generated on the front side by deformation. This will be described with reference to FIG.

For example, as shown in FIG.
When a sine wave AC voltage is applied from the power supply 2 to the first piezoelectric element group 1 from the rear side, as shown in FIG. 3B, when the wing surface 10 side is a positive electrode and the electrode plate 6 side is a negative electrode, 1
The piezoelectric element 1a extends in the moving direction, and the second piezoelectric element 1b
3A, the first piezoelectric element 1a shrinks in the moving direction and the second piezoelectric element when the polarity changes and the wing surface 10 side is a negative electrode and the electrode plate 6 side is a positive electrode as shown in FIG. 1b extends in the moving direction. Since this is repeated alternately, bending vibration occurs on the upper blade surface 10 of the first piezoelectric element group 1, and a standing wave having no direction is generated.

Referring back to FIG. Since a cosine wave AC voltage is applied from the power supply 3 to the second piezoelectric element group 1, the upper wing surface 10 of the second piezoelectric element group 1
Generates a bending vibration and generates a standing wave having no direction. However, since the AC voltage supplied from the power supply 3 is delayed by 90 degrees from the phase of the AC voltage supplied from the power supply 2, the first
A bending vibration that proceeds from the second piezoelectric element group 1 side to the second piezoelectric element group 1 occurs. As described above, the power supply 2 applies a sine-wave AC voltage to the odd-numbered piezoelectric element groups 1 and the power supply 3 applies a cosine-wave AC voltage to the even-numbered piezoelectric element groups 1. Of the blade surface 10 from the rear side to the front side is generated. Here, since the vibration absorber 4 is installed at the front end inside the wing surface 10, the reflected wave component from the front end is absorbed, and the wave energy is converted into electric energy and consumed by the load circuit 5. You. As a result, a traveling wave traveling from the rear side to the front side of the wing surface 10 of the aircraft is generated. In addition, if the position of the vibration absorber 4 is installed on the rear side with the applied phases of the power supply 2 and the power supply 3 reversed, the traveling wave direction is reversed.

When the traveling wave is generated in this way, the transverse wave 7a
2 is combined with the component of the longitudinal wave 7b on the wing surface 10 as shown in FIG.
, The force 7 of the counterclockwise elliptical movement works. Since the force 7 of the elliptical motion acts on the wing surface 10 of the aircraft in the contact area 8 with the bending vibration, energy is given to the fluid molecules in the contact area 8, and the fluid molecules are dragged toward the rear side to be moved at high speed. Fluidized. Therefore, as shown in FIG. 4, if the boundary layer is formed on the entire surface 9 or on a divided surface in which the boundary layer peeling is likely to occur, the peeling of the boundary layer can be suppressed.
Also, rainwater, snow, icing, etc. attached to the wing surface 10 are simultaneously removed by the elliptical motion force 7.

As shown in FIG. 5A, by providing a plurality of grooves 11 extending perpendicularly to the moving direction from the front side to the rear side of the wing surface 10 as shown in FIG. Since the amplitude of the wing surface 10 increases, the force 7 of the elliptical motion increases, and accordingly, the energy given to the fluid molecules in the contact area 8 also increases. Therefore, the effect of suppressing peeling and the effect of removing rainwater and the like are further improved.

(Second Embodiment) FIG. 6 shows a second embodiment of the present invention.
It is a side view which shows the structure outline of the boundary layer separation suppression apparatus of the moving body which concerns on embodiment. An example in which the present invention is applied to the wing surface 10 of an aircraft is shown as in the first embodiment.

The apparatus for suppressing boundary layer separation of a moving body includes a piezoelectric element 12 installed at a rear end inside a wing surface 10 of an aircraft.
And a cylindrical tube 18 covering the piezoelectric element 12 and acting as a strain converting means extending in a direction perpendicular to the moving direction;
A power supply 13 functioning as a voltage supply means for supplying an AC voltage to the piezoelectric element 12; and a vibration absorber installed at the front end inside the blade surface 10 for absorbing wave energy generated on the blade surface 10 and converting the energy into electric energy. 14. Load circuit 1 connected to vibration absorber 14 and consuming converted electric energy
Further, a horn 16 is inserted between the piezoelectric element 12 and the blade surface 10 as a vibration expansion device for expanding and contracting the expansion and contraction of the piezoelectric element 12 and transmitting the expanded and contracted vibration to the blade surface 10.
A horn 17, which is a vibration reducing device for reducing vibration generated on the wing surface 10 and transmitting the vibration to the vibration absorber 14, is interposed between the horn 17 and the wing surface 10.

The piezoelectric element 12 is polarized in a direction perpendicular to the moving direction with the horn 16 side (surface side) as a positive electrode and the opposite side as a negative electrode. It extends in the moving direction by applying a voltage having the opposite side as a negative electrode, and conversely, applying a voltage having the horn 16 side (surface side) as a negative electrode and the opposite side as a positive electrode. To shrink. The horn 16 (front side) is polarized in a direction perpendicular to the moving direction with the horn 16 side (front side) as the negative electrode, and a voltage is applied with the horn 16 side (front side) as the positive electrode and the opposite side as the negative electrode. The voltage may be contracted in the moving direction by applying the voltage, and may be extended in the moving direction by applying a voltage having the horn 16 side (surface side) as a negative electrode and the opposite side as a positive electrode.

The cylindrical tube 18 restricts expansion and contraction of the piezoelectric element 12 in the moving direction.
The distortion that expands and contracts in the moving direction is converted into a distortion that expands and contracts in a direction perpendicular to the moving direction. This piezoelectric element 1
A Langevin-type vibrator is constituted by 2 and the cylindrical tube 18. The vibration absorber 14 is also a Langevin type vibrator composed of a piezoelectric element and a cylindrical tube 19 covering the piezoelectric element from the surroundings, and is used as a power generator.

According to this, when an AC voltage is supplied from the power source 13 to the piezoelectric element 12, the piezoelectric element 12 expands and contracts in the vertical direction due to the operation of the cylindrical tube 18, and the vibration of the horn 1
At 6, it is effectively enlarged and transmitted to the wing surface 10. At this time, the vibration absorber 14 is installed at the front end of the wing surface 10 via the horn 17 and the reflected wave is effectively reduced and consumed by the load circuit 15, so that the traveling wave transmitted from the rear side to the front side is transmitted. Waves are generated. As in the first embodiment, the force of the elliptical motion acts upon the generation of the traveling wave, so that separation of the boundary layer can be suppressed and rainwater can be removed.

According to the embodiment of the present invention, the wing surface 10
An example is shown in which a device for suppressing boundary layer separation of a moving body is installed, but a body, a horizontal tail, a vertical tail, or the like may be used as long as separation occurs. Further, the present invention can be applied not only to aircraft but also to moving objects such as vehicles and ships. Furthermore, according to the present embodiment, the traveling wave is generated from the rear side to the front side,
That is, the force 7 is applied from the front side to the rear side by the elliptical motion. However, the present invention is not limited to this, and the steering can be controlled by applying the force 7 to the front side, left side or right side, or combining a plurality of directions.

[0029]

As described above, according to the first aspect of the present invention, the fluid molecules in the contact area on the surface are dragged backward by the force of the elliptical motion accompanying the generation of the traveling wave, and are fluidized at high speed. Therefore, the separation can be suppressed without requiring a particularly complicated structure by installing the boundary layer on the entire surface or in a divided surface where the separation is likely to occur. In terms of weight, the weight can be reduced as compared with the conventional example. In addition, rainwater, snow, icing, and the like attached to the surface due to the high-speed fluidization of the fluid molecules are also removed.

According to the second aspect of the present invention, since the plurality of grooves provided on the surface of the moving body increase the amplitude of the bending vibration of the surface due to the expansion and contraction of the piezoelectric element group, the force of the elliptical motion increases. The effect of suppressing peeling and removing rainwater and the like is further improved.

According to the third aspect of the present invention, the piezoelectric element is expanded / contracted in a direction perpendicular to the moving direction, the surface is vibrated, and a traveling wave and an elliptical motion are generated. In addition to the effect described above, the number of piezoelectric elements can be significantly reduced.

According to the fourth aspect of the present invention, since the vibration expansion device is interposed between the piezoelectric element and the surface of the moving body, the expansion and contraction of the piezoelectric element may be small. Since the vibration reduction device is interposed between the vibration absorber and the surface of the moving body, the vibration absorber and the load circuit connected thereto may have a small capacity, so that the device can be further reduced in size and weight.

[Brief description of the drawings]

FIG. 1 is a side view showing an outline of a configuration of a boundary layer separation suppressing device for a moving object according to a first embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a part of FIG. 1 when an AC voltage is applied to the piezoelectric element group 1.

3A and 3B are partially enlarged side views showing deformation of a piezoelectric element group 1 and a wing surface 10, wherein FIG. 3A shows a case where no voltage is applied, FIG. 3B shows a positive electrode on the wing surface 10, and a negative electrode on the electrode plate 6. (C) shows a case where a negative electrode voltage is applied to the wing surface 10 and a positive electrode voltage is applied to the electrode plate 6, respectively.

FIG. 4 is a wing surface 1 of an aircraft to which an embodiment of the present invention is applied;
FIG.

FIGS. 5A and 5B are partially enlarged side views showing deformation of a wing surface 10 on which a plurality of grooves 11 are formed, where FIG. 5A is a case where no voltage is applied, and FIG. 6 shows the case where the voltage of the negative electrode is applied.

FIG. 6 is a side view showing an outline of a configuration of a boundary layer separation suppressing device for a moving object according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piezoelectric element group 1a 1st piezoelectric element 1b 2nd piezoelectric element 2, 3 Power supply 4 Vibration absorber 5 Load circuit 6 Electrode plate 7 Force of elliptical movement 7a Transverse wave 7b Longitudinal wave 8 Contact area 9 Range 10 Blade surface 11 Groove 12 Piezoelectric element 13 Power supply 14 Vibration absorber 15 Load circuit 16, 17 Horn 18, 19 Cylindrical tube

Claims (4)

(57) [Claims] 1. A moving direction which is polarized in a direction perpendicular to the moving direction and arranged in parallel with the moving direction inside the surface of the moving body, and the moving direction is controlled by an applied voltage having a positive electrode on the surface side and a negative electrode on the opposite side. And a first piezoelectric element that contracts in the direction of movement by an applied voltage having a negative electrode on the front side and a positive electrode on the opposite side, and a first piezoelectric element polarized in the opposite direction to the first piezoelectric element and A second piezoelectric element which contracts in the moving direction by the applied voltage having a positive electrode and the opposite side as a negative electrode, and conversely extends in the moving direction by the applied voltage having a surface side as a negative electrode and the opposite side as a positive electrode. A plurality of piezoelectric element groups, first voltage supply means for supplying an AC voltage to odd-numbered piezoelectric element groups from the rear side of the moving body in the plurality of piezoelectric element groups, and a moving body in the plurality of piezoelectric element groups. To the even-numbered piezoelectric element group from the rear side. A second voltage supply means for supplying an AC voltage having a phase delayed from the phase of the AC voltage supplied by the pressure supply means, and a second voltage supply means provided at a front end inside the surface of the moving body for absorbing wave energy generated on the surface. An apparatus for suppressing boundary layer separation of a moving body, comprising: a vibration absorber that converts electric energy; and a load circuit that is connected to the vibration absorber and consumes the electric energy. 2. The apparatus according to claim 1, wherein a plurality of grooves extending in a direction perpendicular to the moving direction are provided on a surface of the moving body from a front side to a rear side of the surface. . 3. A moving body, which is disposed at a rear end inside the surface of the moving body and polarized in a direction perpendicular to the moving direction, and is applied to the moving direction by an applied voltage having a positive electrode on the surface side and a negative electrode on the opposite side. A piezoelectric element that expands / shrinks and conversely expands / contracts in the moving direction by an applied voltage with the surface side as a negative electrode and the opposite side as a positive electrode, and a strain that expands and contracts in the moving direction of the piezoelectric element in the moving direction. And a voltage supply means for supplying an AC voltage to the piezoelectric element, and a wave energy generated on the surface of the moving body is provided at a front end of the moving body. An apparatus for suppressing boundary layer separation of a moving object, comprising: a vibration absorber that converts the electric energy into electric energy; and a load circuit that is connected to the vibration absorber and consumes the electric energy. 4. A vibration expansion device interposed between the piezoelectric element and the surface of the moving body, for expanding and contracting the expansion and contraction of the piezoelectric element and transmitting the vibration to the surface of the moving body. The apparatus according to claim 3, further comprising: a vibration reduction device interposed therebetween and reducing vibration generated on the surface of the moving body and transmitting the vibration to the vibration absorber.