KR101409363B1 - Method For Predicting Stability In Strong Wind Rotor Start and Stop - Google Patents

Abstract

Provided is a method for predicting stability during rotor start and stop in a strong wind. The method for predicting stability during rotor start and stop in a strong wind includes a step in which one strong wind generating device is used to measure the speed of the strong wind that is reached every time the distance from the strong wind generating device is changed and a range having the same speed; a step in which the number of strong wind generating devices is determined in view of the diameter of a rotor of a test object helicopter so that the strong wind of the same speed can reach the entire rotor of the test object helicopter; a step in which the fixed number of strong wind generating devices are arranged horizontally; a step in which the speed of the strong wind that is reached every time the distances from the arranged strong wind generating devices are changed is measured again; and a step in which the strong wind of the arranged strong wind generating devices is used to perform a rotor start and stop test in the strong wind that is required in helicopter design.

Description

Technical Field [0001] The present invention relates to a method for predicting stability of starting and stopping a rotor in a high-

The present invention relates to a method for predicting the stability of a helicopter under strong wind by performing a strong wind test regardless of whether it is moved to a strong wind or a strong wind blows, .

In order to develop a new aircraft, it is necessary to design it to satisfy various design requirements and to test whether it actually meets the design requirements.

In particular, when designing a helicopter, stability is required to be maintained when starting and stopping the rotor under strong wind conditions.

The rotor blades are rotated in three directions. There is a pitch or feathering that rotates about the rotor blade axis, flapping that rotates the blade up and down, and a lead-lag motion that rotates in the blade forward direction. Also, deflection of the blade itself occurs in the vertical direction due to self weight or lift of the blade. Such movement and sagging of the blade should not cause the helicopter body to become unstable or cause the blade to collide with the helicopter. During the flight, the blade is not deflected downward due to centrifugal force. However, when the rotor on the ground is stopped, due to the strong wind, the blade is flapping and flapping downward. At this time, if the downward flapping range is large, there is a collision between the blades and the body, so that the rotor has a device for restricting the flapping range to a small value at the time of non-rotation or at low RPM. The state in which a collision or minimum gap between the rotor blade and the fuselage can occur is passed through the RPM which is switched from the non-rotation state of the rotor to the normal rotation RPM at the start of the rotor to a small flapping range, In a large range, when the centrifugal force transmitted to the rotor blade is low, the rotor blade is swung due to the strong wind and the maximum deflection occurs in the downward direction. Or just before the rotor is stopped and the RPM is switched to the small flapping range from the large flapping range down to the rotor stopping, that is, when the flapping range is large, the centrifugal force transmitted to the rotor blade In this low state, the rotor blades slope due to the influence of strong winds and the maximum deflection occurs in the downward direction.

The helicopter must have the ability to operate under limited strong winds, and particularly when the rotor is started and stopped under strong wind, the possibility of collision with the fuselage due to blade flapping and deflection described above, and blade flapping and chattering, It is necessary to identify the influence on the posture maintenance and operation and to present the operable strong wind conditions.

However, it is not easy to identify the area where strong winds meet the strong wind conditions required in designing the helicopter. Even if the region satisfying the strong wind conditions is found, it is costly to move the helicopter under development to the area There are limitations in terms of time, and it has been difficult to wait indefinitely for natural strong winds to occur due to restrictions on the helicopter development schedule.

To solve this problem, it is necessary to have an apparatus capable of generating artificial strong winds. However, there is not a large enough equipment to cover the diameter of the helicopter rotor, and it is possible to use several small-sized identical equipment. There is a high probability that the test schedule will be disrupted by the limited equipment.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for predicting the stability of a helicopter under a strong wind by performing a strong wind test regardless of whether the wind moves to a strong wind area or a strong wind blows.

The objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

According to an aspect of the present invention, there is provided a method for testing a high-altitude wind turbine, comprising the steps of measuring a velocity of a strong wind and a range having the same velocity, Determining the number of high-wind generating devices by taking into account the rotor diameter of the test target helicopter so that strong winds of the same speed can be reached throughout the rotor of the helicopter, arranging the numbered high- Re-measuring the speed of the gale to be reached every time the distance from the device is different, and performing a start and stop test of the rotor under the strong wind required when designing the helicopter using the strong wind of the deployed gale generator.

According to another aspect of the present invention, in the step of determining the number of high wind generating apparatuses, the rotor diameter of the helicopter to be tested is determined by dividing the rotor diameter by a range having the same speed measured in the speed measuring step, The following is determined by raising.

According to another aspect of the present invention, the arranging step is arranged at equal intervals so that the interval between the strong wind generating devices is 1 to 3 m.

According to another aspect of the present invention, there is provided a method of testing a turbomachine, the method comprising the steps of: performing a test at a wind speed of 45 knots in front of the helicopter to determine whether the rotor blade collides with the forward / .

According to another aspect of the present invention, there is provided a method of testing a helicopter comprising the steps of: performing a test at a wind speed of 45 knots in a direction of 30 degrees in front of a helicopter, .

According to another aspect of the present invention, there is provided a method for testing a rotor of a helicopter, the method comprising the steps of: performing a test at a wind speed of 30 knots at a side of the helicopter, .

According to another aspect of the present invention, the test step determines whether the rotor collides with the rear body of the helicopter and the stability of the helicopter when the rotor starts and stops under the wind speed of 25 knots in the rear of the helicopter.

The method of predicting the stability of the starting and stopping of a strong wind rotor according to the present invention is to predict the stability of a helicopter under strong wind by performing a start and stop test of a rotor under a strong wind irrespective of whether it moves to a strong wind or the wind blows have.

1 is a flowchart illustrating a method of predicting stability at the time of starting and stopping a strong wind rotor according to an embodiment of the present invention.
FIG. 2 is a graph showing speeds along the distance of strong winds generated through one high-wind generating apparatus. FIG.
3 is a view illustrating a rotor diameter of a helicopter to be tested by a method for predicting stability at the time of start and stop of a strong wind rotor according to an embodiment of the present invention.
FIG. 4 is a graph illustrating the velocity of strong winds according to distances of a strong wind generating apparatus arranged by a method for predicting stability at the time of start and stop of a strong wind rotor according to an embodiment of the present invention. FIG.
5 is a view showing a state in which an actual test is performed by a method for predicting stability at the time of starting and stopping a strong wind rotor according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings and the following description. However, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Rather, the embodiments disclosed herein are being provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. Like reference numerals designate like elements throughout the specification. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprises "and / or" comprising ", as used herein, unless the recited element, step, operation, and / Or additions.

Hereinafter, a method for predicting stability at the time of starting and stopping a strong wind rotor according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5. FIG.

FIG. 1 is a flowchart showing a method for predicting stability at the time of start and stop of a strong wind rotor according to an embodiment of the present invention, FIG. 2 is a graph showing a speed according to a distance of strong wind generated through one strong wind generating apparatus, 3 is a view illustrating a rotor diameter of a helicopter to be tested by a method for predicting stability at the time of start and stop of a strong wind rotor according to an embodiment of the present invention. And a method for predicting stability at the time of stoppage. FIG. 5 is a graph showing the velocity of strong wind according to the distance of a strong wind generating apparatus disposed by a method for predicting the stability at the time of starting and stopping the strong wind in accordance with an embodiment of the present invention Fig. 2 is a view showing a scene in which a test is actually performed.

Referring to FIGS. 1 and 2, in the step S1 of measuring the speed of a strong wind, a speed of a strong wind and a speed having the same speed are measured every time the distance is changed using a strong wind generating apparatus. The above-described apparatus for generating a strong wind is mainly used for agricultural use, and a wide-area spreader used for spraying pesticides to distant places of 100 m or more can be used.

The maximum wind speed of 45 knots is required for starting and stopping the rotor under the strong wind. In actual test, the test is carried out while gradually increasing the wind speed.

Therefore, in the step of measuring the strong wind speed (S1), it is determined from which distance the wind of 45knot corresponding to the maximum wind speed condition is reached to which extent, and as shown in FIG. 2, And the same wind speed was measured in the range of 2 m in diameter.

That is, in the step of measuring the strong wind speed (S1), it is confirmed whether the wind velocity of the strong wind generating apparatus to be used for the test meets the wind speed requirement of the test subject and how much of the wind speed wind speed is discharged.

Referring to FIGS. 1 and 3, the number of high-wind generating apparatuses is determined with reference to FIGS. 1 to 3 so that strong winds of the same speed can reach the entire rotor of the test target helicopter in the number-of-

At this time, the number of the strong wind generating devices is determined by dividing the rotor diameter of the helicopter to be tested by a range having the same speed measured in the speed measuring step (S1), and deciding the decimal point by rounding down.

In case of the helicopter shown in FIG. 2, the rotor diameter is 15.8 m and the same strong wind is reached in the range of 2 m in the case of the strong wind generating apparatus, the result is 15.8 m / 2 m = 7.9. When the decimal point is raised, .

Referring to FIGS. 1 and 4, in the arrangement step S3, the number of the high-wind generating apparatuses determined in the number-of-high-wind generating apparatus determination step S2 is arranged transversely.

At this time, it is possible to arrange them at equal intervals such that the interval between the strong wind generating devices is 1 to 3 m.

As shown in FIG. 2, as the distance from the strong wind generating apparatus increases, the velocity of the strong wind decreases. However, since the range of the strong wind spreads into a fan shape, when the strong wind generating apparatus is disposed at equal intervals in the lateral direction, . Accordingly, in consideration of the above-described situation, the apparatus for generating high winds is arranged at a predetermined interval in the lateral direction, and the velocity of strong wind is measured again in the step of measuring the strong wind speed, which will be described later (S4).

In the step of re-measuring the strong wind speed (S4), the velocity of the strong wind generated in the plurality of strong wind generating devices arranged in the arrangement step (S3) may be varied to reach the entire speed of the rotor of the test target helicopter Whether or not to measure again.

As shown in FIG. 4, it can be seen that a strong wind of 25 knots is reached at 30 knots at a distance of 45 m from the distance of 17 m, and at a distance of 50 m from a distance of 36 m to a width of covering the entire portion of the rotor of the helicopter to be tested.

In the test execution step S5, the start and stop test of the rotor is performed under the strong wind required when designing the helicopter by using the strong wind of the arranged strong wind generating apparatus.

As shown in FIG. 4, the starting and stopping tests of the strong-wind lower rotor start and stop the rotor at a forward speed of 30 knots and a forward speed of 45 knots under a strong wind condition, a 30 knot strong wind condition at the side, A test is performed to determine whether the blade collides with the front and rear helicopters of the helicopter and the stability of the helicopter.

The actual test procedure should start with a low wind speed and approach stability with high wind speed. Therefore, it proceeded in three steps of 16, 21, and 25 knot from the rear of the helicopter, and then proceeded to three stages of 19, 25, and 30 knot on the side of the helicopter, and then proceeded to four stages of 30, 35, And then proceeded in two steps of 35 and 45 knot in the direction of 30 degrees forward from the helicopter. This shows that the helicopter is disposed at a distance at which the actual test is performed as shown in FIG. 4, and the corresponding wind speed at each distance is shown.

The stability of the helicopter fuselage is judged based on whether the fuselage is stable enough to feel that the pilot can safely operate the helicopter under strong winds and whether the device controlling the flapping amount of the rotor mounted in the helicopter is operating normally.

The normal operation of the device for controlling the amount of flapping of the rotor is visually observed as the amount of flapping of the rotor blade is large and the blade moves considerably downward.

As shown in FIG. 5, it is possible to determine whether the helicopter is stable in a strong wind condition by performing an actual test by a method of predicting stability at the time of starting and stopping a strong wind rotor according to an embodiment of the present invention.

Therefore, according to the present invention, there is no need to wait for a place or time suitable for the strong wind speed, and it is possible to carry out the test using the wide-area spreader used for agricultural use, It is possible to eliminate the inconvenience caused in terms of the test schedule adjustment and the test schedule adjustment.

In actual arrangement, the spacing between adjacent cylindrical cylindrical strong winds is about 3.2 m, the distance between the cylindrical outer shape of the strong winds and the cylindrical outer shape of the adjacent winds is about 1.4 m, and the vehicle equipped with the strong winds Was about 1 m.

Since the strong wind can rotate vertically and horizontally, after the arrangement of the strong winds, the up / down angle of the strong wind was adjusted to generate 45 knots at the height of the rotor center of about 4 m. The upward / downward / leftward / rightward angles of the winds were adjusted so that the winds emitted from the winds would blow toward the helicopter.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. I will understand. Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be determined by all changes or modifications derived from the scope of the appended claims and the appended claims.

Claims (7)

Measuring a range of a strong wind and a speed having the same velocity each time a distance is changed in a strong wind generating device by using one strong wind generating device;
Determining the number of high wind generating devices by taking into consideration the rotor diameter of the test target helicopter so that strong winds of the same speed can be reached throughout the rotor of the test target helicopter;
Arranging the number of the determined strong wind generating apparatuses transversely;
Remeasuring the velocity of the strong wind that is reached every time the distance from the arranged strong wind generator is varied; And
And performing a start and stop test of the rotor under the strong wind required in designing the helicopter using the strong wind of the deployed strong wind generator. The method according to claim 1,
Wherein the step of determining the number of high wind generating devices determines a value obtained by dividing a rotor diameter of a helicopter to be tested by a range having the same speed measured in the speed measuring step, How to predict stability. The method according to claim 1,
Wherein the arranging step is arranged at equal intervals so that the interval between the strong wind generating devices is 1 to 3 m. The method according to claim 1,
The test execution step is a method for predicting stability of starting and stopping of a strong wind rotor to judge whether the helicopter crashes in front of and behind the helicopter and the stability of the helicopter when the rotor starts and stops under the wind speed of 45 knots in front of the helicopter . The method according to claim 1,
In the test step, when the start and stop of the rotor are performed at a wind speed of 45 knots in the direction of 30 degrees from the front of the helicopter, stability of starting and stopping of a strong wind rotor to judge whether the helicopter crashes in front of or behind the helicopter, How to predict. The method according to claim 1,
The test execution step is a method for predicting stability of starting and stopping of a strong wind rotor to judge whether the rotor blades collide with the front and rear helicopters of the rotor blades and the stability of the helicopter when the rotor starts and stops under the wind speed of 30 knots in the side of the helicopter . The method according to claim 1,
The test execution step predicts the stability at the time of starting and stopping the strong wind rotor to judge whether the rotor collides with the rear fuselage of the rotor and the stability of the helicopter when the rotor starts and stops under the wind speed of 25 knots in the rear of the helicopter.

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