JP5481263B2 - Wings - Google Patents

Description

  The present invention relates to a blade exposed to a predetermined fluid.

An axial fluid device such as an aircraft engine includes a moving blade row and a stationary blade row arranged in the axial direction. The moving blade row is constituted by a plurality of moving blades, and the stationary blade row is constituted by a plurality of stationary blades.
In such an aircraft engine, by rotating the moving blade row, a velocity deficient region having a slow flow with respect to the surroundings is generated on the downstream side of the moving blade. The flow in the velocity deficit region is generally called a wake (also called wake or wake), and has a narrow width and a strong velocity deficit immediately after the moving blade, and the width increases as the distance from the moving blade increases. Spread and weaken velocity deficits.

Such a speed deficit region causes noise and vibration. Therefore, Patent Document 1 proposes an invention for recovering velocity deficiency with a simple structure.
Specifically, in the invention according to Patent Document 1, a fluid channel that is connected from the pressure surface to the suction surface or the trailing edge is formed inside the blade, and the fluid on the pressure surface side is passed through the fluid channel. By supplying the velocity deficient region, the velocity deficit is weakened to recover the speed deficit.

JP 2007-278187 A

  However, although the invention disclosed in Patent Document 1 is useful in that the recovery of velocity deficit can be achieved without providing a complicated structure, the flow velocity of the fluid ejected from the fluid flow path is slow, and the velocity deficiency is sufficiently high. It is difficult to recover.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to improve the recovery rate of velocity deficits as compared with the prior art.

  The present invention adopts the following configuration as means for solving the above-described problems.

  A first aspect of the present invention is a blade exposed to a fluid, and includes a take-in means for taking in the fluid from an introduction hole formed in a front edge portion, and a jet of the taken-in fluid from a lead-out hole formed in a rear edge portion. Then, a configuration in which a speed deficiency recovery unit that supplies the speed deficit region is provided is adopted.

  According to a second invention, in the first invention, a configuration is provided in which acceleration means for accelerating the fluid taken in is provided.

  According to a third aspect of the present invention, in the second aspect of the invention, the lead-out hole is narrowed with respect to the introduction hole.

  In a fourth aspect based on the second or third aspect, the introduction hole is a rectangular opening whose width in the blade height direction is eight times the width in the blade thickness direction. The configuration is a circular opening.

According to the present invention, the fluid taken in from the front edge is ejected to the velocity deficient region at the rear edge. As a result, the amount of fluid ejection (amount of ejection) is greater than when a fluid flow path is provided from the positive pressure surface to the negative pressure surface or the trailing edge, and the recovery rate of velocity deficiency can be improved.
Further, the fluid supplied to the velocity defect region is accelerated by the acceleration means and the velocity defect recovery means. For this reason, the flow velocity of the fluid supplied to the velocity deficient region is increased, and the flow velocity in the velocity deficient region can be increased overall as compared with the conventional method. As a result, the speed deficit is recovered more than before.
Therefore, according to the present invention, it is possible to improve the recovery rate of the speed deficit than before.

It is a perspective view which shows schematic structure of the wing | blade in one Embodiment of this invention. It is a perspective view which shows schematic structure of the conventional wing | blade. It is a schematic diagram which shows the simulation result using the conventional wing | blade and the wing | blade in one Embodiment of this invention. It is a schematic diagram which shows the simulation result using the conventional wing | blade and the wing | blade in one Embodiment of this invention. It is a graph which compares the simulation result using the conventional wing | blade, and the simulation result using the wing | blade in one Embodiment.

  Hereinafter, an embodiment of a wing and a turbofan engine according to the present invention will be described with reference to the drawings. In the following description, the scale of each member is appropriately changed in order to make each member a recognizable size.

FIG. 1 is a perspective view showing a schematic configuration of a wing 1 of the present embodiment.
As shown in this figure, the blade 1 of this embodiment is used as a fan rotor blade or the like exposed to a fluid such as outside air, and has a bypass flow path 2 (acceleration means and speed deficit recovery) for venting outside air. Means).
And the wing | blade 1 of this embodiment has a shape whose wing | blade height is 127 mm and a chord length is 20 mm.

The bypass flow path 2 takes outside air around the blade 1 and supplies it to a velocity deficit region formed on the downstream side of the trailing edge 1b of the blade 1, and as shown in FIG. A lead-out hole 2b and an internal flow path 2c are provided.
As shown in FIG. 1, a plurality of bypass flow paths 2 are provided in the blade height direction of the blade 1.

The introduction hole 2a is an opening end of the bypass channel 2 on the front edge portion 1a side, and is formed in the front edge portion 1a.
In addition, the area in the vicinity of the leading edge 1a is an area in which the outside air supplied from the upstream side of the blade 1 collides with the leading edge 1a and branches to the ventral side and the back side of the blade 1. It is a region where the flow velocity is slow (ie, a stagnation region). That is, the introduction hole 2a is formed in the front edge portion 1a so as to face the stagnation region.
In the blade 1 of the present embodiment, the introduction hole 2a has a direction connecting the trailing edge portion 1b and the leading edge portion 1a of the blade 1 in the chord direction and a direction connecting the hub portion 1c of the blade 1 and the tip portion 1d. When the blade height direction and the direction connecting the suction surface to the pressure surface of the blade are the blade thickness direction (see FIG. 1), the blade height direction is 16 mm and the blade thickness direction width is 2 mm. ing. In addition, the said numerical value is an example and the introduction hole 2a can take in external air efficiently because it is a rectangular-shaped opening whose width | variety of a blade height direction is 8 times the width | variety of a blade thickness direction.

The lead-out hole 2b is an open end of the bypass channel 2 on the rear edge 1b side, and is formed in the rear edge 1b.
And in the wing | blade 1 of this embodiment, the derivation | leading-out hole 2b is made into the circular shape of diameter 2mm. That is, in the blade 1 of the present embodiment, the outlet hole 2b has a smaller cross-sectional area (flow channel area) than the introduction hole 2a. That is, the lead-out hole 2b is narrower than the introduction hole 2a in the blade 1 of the present embodiment. In addition, the said numerical value is an example. It is also possible to change the diameter of the lead-out hole 2b.

The internal flow path 2c is a flow path that connects the introduction hole 2a and the lead-out hole 2b, and is formed inside the blade 1 so as to extend in the chord length direction.
The internal flow path 2c is connected to the introduction hole 2a and has the same cross-sectional shape as the introduction hole 2a (that is, a rectangular shape having a width in the blade height direction of 16 mm and a width in the blade thickness direction of 2 mm). It is formed by a part-side internal flow path 2c1 and a trailing edge-side internal flow path 2c2 that is connected to the lead-out hole 2b and has the same cross-sectional shape as the lead-out hole 2b (that is, a circular shape with a diameter of 2 mm).

In the blade 1 of this embodiment having such a configuration, when the blade 1 is rotated along with the rotation of the disk to which the blade 1 is attached, and the blade 1 is exposed to the outside air flow, it is introduced by the dynamic pressure of the outside air. Outside air is taken into the bypass channel 2 from the hole 2a. The outside air taken into the bypass channel 2 passes through the internal channel 2c and is ejected from the outlet hole 2b.
Here, in the blade 1 of the present embodiment, the lead-out hole 2b is narrowed with respect to the introduction hole 2a. For this reason, the outside air taken into the bypass channel 2 from the introduction hole 2a passes through the outlet hole 2b having a small channel area so that the outside air flows around the rear edge 1b at the same speed or close to the speed. It is accelerated and spouted.
The outside air that has been accelerated and ejected is supplied to a velocity deficit region that is formed on the downstream side of the trailing edge 1b as the blade 1 is rotated.

When the outside air accelerated so as to approach or approach the speed of the outside air flow around the rear edge 1b is supplied to such a velocity deficient region, the flow rate of the outside air in the velocity deficient region is increased, The deficit recovers.
At this time, if the distance between the position where the outlet hole 2b is narrowed and the outlet hole 2b1 are separated, the effect of accelerating the outside air cannot be sufficiently obtained. For example, the distance between the outlet hole 2b1 and the position where the outlet hole 2b is narrowed is preferably 10 times or less the diameter of the outlet hole 2b1.

As described above, the blade 1 of the present embodiment takes in outside air from the introduction hole 2a formed in the front edge portion 1a, and accelerates the taken-in outside air to eject from the outlet hole 2b formed in the rear edge portion 1b. And a bypass channel 2 for supplying the velocity deficient region.
According to the blade 1 of this embodiment as described above, the bypass air 2 accelerates the outside air supplied to the velocity deficient region. For this reason, the flow velocity of the outside air supplied to the velocity deficient region is increased, and the flow velocity in the velocity deficient region can be increased as a whole as compared with the conventional method. As a result, the speed deficit is recovered more than before.
Therefore, according to the wing 1 of the present embodiment, it is possible to improve the recovery rate of speed deficits compared to the conventional art.

  Further, according to the blade 1 of the present embodiment, the outside air in the bypass channel 2 is accelerated by restricting the outlet hole 2b with respect to the inlet hole 2a. For this reason, outside air can be accelerated in the bypass flow path 2 without providing a complicated mechanism.

(simulation result)
Next, the simulation result using the wing | blade 1 of this embodiment is demonstrated.
In addition to the simulation results using the blade 1 of the above embodiment, as shown in FIG. 2, a simulation using the blade 100 in which both the introduction hole 2a1 and the lead-out hole 2b1 are circular with a diameter of 2 mm is also performed. did.

FIG. 3 is a diagram schematically showing the flow velocity distribution of the outside air obtained by the simulation using the blade 100 shown in FIG. 2, and (a) is a diagram of the conventional blade viewed from the blade height direction. (B) is the figure which looked at the blade | wing 1 of the said embodiment from the blade height direction.
On the other hand, FIG. 4 is a diagram schematically showing the flow velocity distribution of the outside air obtained by the simulation using the blade 100 shown in FIG. 2. FIG. 4A shows the blade 100 shown in FIG. (B) is the figure which looked at the wing | blade 1 of the said embodiment from the wing | blade thickness direction.
3 and 4, the flow direction of the outside air at each location is indicated by the direction of the arrow, and the flow velocity at each location is indicated by the length of the arrow.

As shown in FIGS. 3A and 4A, in the blade 100 shown in FIG. 2, the flow rate of the outside air ejected from the outlet hole 2b is larger than the flow rate of the outside air before being ejected from the outlet hole 2b. It can be seen that the outside air is not accelerated.
On the other hand, as shown in FIGS. 3 (b) and 4 (b), in the blade 1 of the above embodiment, the flow rate of the outside air ejected from the outlet hole 2b is equal to that of the outside air before being ejected from the outlet hole 2b. It changes greatly with respect to the flow velocity, and it turns out that the external air is accelerated.

  In FIG. 4B, since the inner wall surface of the blade is bent at a right angle, a vortex is generated. This vortex can be easily eliminated, for example, by making the inner wall surface of the blade a smooth curved surface.

FIG. 5 is a graph showing the velocity deficiency recovery rate, the ejection velocity ratio (ejection velocity / ambient velocity), the flow rate, and the lift coefficient, which are obtained from the simulation results, as ratios to the conventional blade.
As shown in this figure, the blade 100 shown in FIG. 2 has a small ejection velocity ratio (that is, the flow velocity of the outside air ejected from the outlet hole 2b1 is slower than that of the blade 1), and the velocity deficiency recovery rate is small. However, as will be described later, an increase in the ejection rate (ejection flow rate) was confirmed, and it was found that the speed deficit recovery rate was improved.
On the other hand, the blade 1 of the above-described embodiment has a large ejection speed ratio (that is, the flow velocity of the outside air ejected from the outlet hole 2b is relatively fast), and the speed deficiency recovery rate is large.
Also by such simulation, it was confirmed that the recovery rate of velocity deficiency was improved as compared with the conventional case, particularly when the lead-out hole 2b is formed in the rear edge portion 1b.

In addition to the above simulation, a simulation was performed to compare the wing 1 of the above embodiment with the wing having the introduction hole 2a described in Patent Document 1 formed on the abdominal surface.
As a result, the injection rate from the lead-out hole 2b in the blade 1 of the above embodiment (the amount of discharge with respect to the surrounding flow rate) was 0.9% and the lift coefficient was 0.31, whereas the introduction hole 2a was on the stomach surface. The ejection rate of the formed wing was 0.52%, and the lift coefficient was 0.3.
From this result, it was found that the introduction hole 2a is preferably formed in the front edge portion 1a.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

For example, in the above embodiment, the example in which the blade 1 is used as a fan blade has been described.
However, the present invention is not limited to this, and the blades of the present invention can be used for turbine blades and compressor blades.

Moreover, in the said embodiment, the example in which the fluid in this invention is external air (air) was demonstrated.
However, the present invention is not limited to this, and the fluid in the present invention may be water vapor or liquid.

  DESCRIPTION OF SYMBOLS 1 ... Wing | blade, 1a ... Front edge part, 1b ... Rear edge part, 2 ... Bypass flow path (take-in means, acceleration means, speed deficit recovery means), 2a ... Inlet hole, 2b ... Outlet hole, 2c: Internal flow path

Claims (3)

A wing that is exposed to fluid,
An intake means for taking in the fluid from an introduction hole formed in the front edge;
Velocity deficiency recovery means for ejecting the taken-in fluid from the outlet hole formed in the rear edge and supplying the fluid to the velocity deficiency region ;
And an accelerating means for accelerating the taken-in fluid . Wing according to claim 1, characterized in that said outlet hole is narrowed with respect to the introduction hole. The introduction hole is wing the height direction of the width of eight times the rectangle-shaped opening of the width of the blade thickness direction, according to claim 1 or 2, wherein the lead-out hole is characterized in that it is a circular opening Wings listed.

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