KR102595973B1 - Thrust And Drag Estimation Method Using Magnus Rotor Of Ship - Google Patents

Abstract

The present invention relates to a method for estimating thrust and drag using a Magnus rotor of a ship, including at least one Magnus rotor for driving a ship, the ship having a support part supporting the Magnus rotor, and the support part having a Magnus rotor. At least four strain gauges are provided to estimate thrust and drag, and a measurement step of measuring the deformation value of the support using the at least four strain gauges; And an estimation step of estimating the thrust and drag of the ship using the values measured through the measurement step; The at least four strain gauges are disposed on the circumferential surface of the support at a certain height from the deck without influence of the lower bearing of the support, and are arranged at an angle. Thrust and drag using the Magnus rotor of the ship. An estimation method is proposed.

Description

Thrust And Drag Estimation Method Using Magnus Rotor Of Ship}

The present invention relates to a method for estimating thrust and drag using the Magnus rotor of a ship in a ship including at least one Magnus rotor for driving the ship. It is possible to estimate the thrust and drag due to wind from the operation of the Magnus rotor. At least four strain gauges are attached at an angle on the surface of the cylindrical support (Steel Support) structure that supports the rotating part of the ship's Magnus rotor, on the surface perpendicular to the ship's direction of travel and on the side perpendicular to the ship's width direction. This relates to a method of estimating thrust and drag due to wind load using a ship's Magnus rotor, which can estimate the thrust and drag of.

Magnus rotors are also referred to as Flettner rotors or rotor sails. Ships including a Magnus rotor as a drive device are known from the prior art.

Magnus rotors are used particularly on ships to provide additional driving force using the Magnus effect. The Magnus effect refers to the generation of transverse force due to fluid flowing into a cylinder rotating around its longitudinal axis. Lateral forces act perpendicular to the inlet flow direction. The flow around a rotating cylinder can be interpreted as a superposition of homogeneous flow and vortices around the body. The uneven distribution of the overall flow results in an asymmetric pressure distribution around the cylinder. Therefore, the ship is equipped with rotating rotors or rotary rotors that generate a force perpendicular to the effective wind direction in the wind flow, that is, the wind direction corrected with the maximum speed. The force thus generated can be used to propel the ship, similar to when sailing. At this time, the lateral force is generated when the rotating surface of the cylinder and the air flowing around it move in the same direction.

The rotor must be fixedly connected to the hull to direct the lateral force to the hull. In known rotors, this is achieved by a support that supports the Magnus rotor, and the rotor is rotatably mounted on the support. At this time, the support portion supporting the Magnus rotor is typically designed to accommodate the force acting on the bearing device in the radial direction. In that case, the magnitude of the lateral force generated by the Magnus rotor depends on the one hand on the size of the rotor and its rotational speed and on the other hand on the speed of the wind flowing around the rotor. However, in addition to the lateral force generated by the Magnus rotor itself, the wind force acting on the surface of the rotor facing the wind additionally acts on the rotor.

In order to avoid damage due to overload, it is desirable to know the forces acting on the Magnus rotor and especially the forces acting on the supports supporting the Magnus rotor. Additionally, it is desirable to be able to determine the direction of forces acting on the rotor or the direction of forces acting on the receiving unit, so that control of the rotor can be performed depending on the wind direction.
Related prior documents include [Patent Document 1] Republic of Korea Patent Publication No. 10-1042764 (June 20, 2011) and [Patent Document 2] Republic of Korea Patent Publication No. 10-1488836 (February 3, 2015). .

Therefore, the present invention aims to solve the above-mentioned problems, and controls the driving of the Magnus rotor through a thrust and drag estimation method using the Magnus rotor of a ship, and the thrust and drag caused by the wind from the operation of the Magnus rotor. The purpose is to provide a thrust and drag estimation method using the ship's Magnus rotor, which makes it possible to estimate and understand.

According to one aspect of the present invention for achieving the above object, a method for estimating thrust and drag using a Magnus rotor of a ship includes at least one Magnus rotor for driving the ship, and the ship supports the Magnus rotor. A measurement step of providing a support part, the support part being equipped with at least four strain gauges to estimate the thrust and drag of the Magnus rotor, and measuring a deformation value of the support part using the at least four strain gauges; And an estimation step of estimating the thrust and drag of the ship using the values measured through the measurement step; The at least four strain gauges are arranged on the circumferential surface of the support part at a certain height from the deck, which is not affected by the lower bearing of the support part, and are arranged at an angle with each other.

Preferably, the at least four strain gauges include first and second strain gauges for estimating thrust on a plane perpendicular to the direction of travel of the ship, and a second strain gauge for estimating drag on a plane perpendicular to the width direction of the ship. It is characterized in that 3rd and 4th strain gauges are provided.

More preferably, the first and second strain gauges are disposed attached to the support portion at 45 degrees and 135 degrees, and the third and fourth strain gauges are disposed attached to the support portion at 45 degrees and 135 degrees. It is characterized by

Also preferably, the strain gauge attached to the support portion is additionally provided with a dummy strain gauge on opposite sides of the first strain gauge and the second strain gauge in consideration of gauge measurement failure, and a third strain gauge is provided. It is characterized in that a dummy strain gauge is provided on opposite sides of the gauge and the fourth strain gauge.

Also preferably, the estimation step includes deriving the shear stress from the value measured from the first and second strain gauges through the measurement step; And a step of calculating and estimating thrust and drag from the derived shear stress through the maximum shear stress formula.

Also preferably, the estimation step includes calculating and deriving shear stress from measurement data measured in a first strain gauge, and determining thrust from the derived shear stress through a maximum shear stress formula; And a step of calculating and deriving the shear stress from the measurement data measured by the second strain gauge, and determining the drag force from the derived shear stress through the maximum shear stress formula.

Also preferably, at least four strain gauges are arranged at a certain height of 8 to 12 meters from the deck, which is not affected by the lower bearing of the support part.

According to the present invention, the driving of the Magnus rotor is controlled through a thrust and drag estimation method using the Magnus rotor of a ship, and it is possible to estimate the thrust and drag due to wind from the operation of the Magnus rotor.

Figure 1 is a schematic conceptual diagram showing the position where a strain gauge is provided in the Magnus rotor according to the present invention.
Figures 2 and 3 are conceptual diagrams showing the arrangement of strain gauges according to the present invention.
Figure 4 is a diagram showing the concept of estimating Magnus rotor thrust and drag using a strain gauge according to the present invention.
Figures 5 and 6 are diagrams showing shear stress according to height considering the wind direction by applying the operating load of the Magnus rotor according to the present invention.
Figure 7 is a diagram showing the arrangement of a strain gauge for thrust estimation and a strain gauge for drag estimation according to the present invention.

In order to fully understand the operational advantages of the present invention and the objectives achieved by practicing the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the structure and operation of a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. Here, in adding reference numerals to components in each drawing, it should be noted that identical components are indicated with the same reference numerals as much as possible, even if they are shown in different drawings.

The following examples may be modified into various other forms, and the scope of the present invention is not limited to the following examples.

Figure 1 is a schematic conceptual diagram showing the position where the strain gauge is provided in the Magnus rotor according to the present invention, Figures 2 and 3 are conceptual diagrams showing the arrangement of the strain gauge according to the present invention, and Figure 4 shows the strain gauge according to the present invention. It is a drawing showing the used Magnus rotor thrust and drag estimation concept, and Figures 5 and 6 are drawings showing the shear stress according to height considering the wind direction by applying the operating load of the Magnus rotor according to the present invention, and Figure 7 is This is a diagram showing the arrangement of a strain gauge for thrust estimation and a strain gauge for drag estimation according to the present invention.

1 to 3, in a ship including at least one Magnus rotor for driving the ship, the ship is provided with a support part 20 that supports the Magnus rotor, and the deformed state of the support part 20 and its A strain gauge is placed on the support portion 20 to measure the amount.

At this time, at least four strain gauges are arranged, and first and second strain gauges 110 and 120 for measuring thrust may be provided on a surface perpendicular to the direction of movement of the ship, and the width of the ship Third and fourth strain gauges 210 and 220 for measuring drag may be provided on a surface perpendicular to the direction, and may be arranged on the circumferential surface of the support portion 20 at an angle with each other.

At a certain height without the influence of the lower bearing on the surface of the cylindrical steel support structure that supports the rotating part of the Magnus rotor, the plane perpendicular to the ship's direction of travel (thrust measurement) and the plane perpendicular to the ship's width direction (drag measurement) Strain gauges are attached in the 135 degree and 135 degree directions, respectively.

At this time, a certain height without the influence of the lower bearing can be set through structural analysis described later, and is set at a height of approximately 8 to 12 meters (m), preferably 10 meters (m), from the ship deck.

At this time, the effective measurement points are 1 point each for the thrust gauge and drag gauge, but in consideration of gauge measurement failure, an additional dummy strain gauge can be installed on the opposite side.

That is, first to fourth dummy strain gauges (130, 140, 230, 240) are arranged in the same arrangement on opposite sides of the first and second strain gauges (110, 120) and the third and fourth strain gauges (210, 220). It can be provided as an angle.

In addition, the position where the first and second strain gauges 110 and 120 are disposed around the support is used to measure thrust on a plane perpendicular to the direction of travel of the ship at a point H at a position of 10 m from the deck. The first strain gauge 110 may be arranged in a 45 degree direction and the second strain gauge 120 may be arranged in a 135 degree direction.

In addition, in order to measure drag, a third strain gauge 130 is arranged in a 45 degree direction on a side perpendicular to the width direction of the ship at a point H at a position of 10 m from the deck, and a fourth strain gauge 140 is installed. It can be arranged in a 135 degree direction.

Therefore, first and second strain gauges 110 and 120 may be provided to measure thrust on a surface perpendicular to the direction of travel of the ship, and third and second strain gauges 110 and 120 may be provided to measure drag on a surface perpendicular to the width direction of the ship. 4 Strain gauges 210, 220 may be provided, and may be arranged on the circumferential surface of the support 20 to form an angle, and the shear stress is derived from the values measured from the first to fourth strain gauges 110, 120, 210, 220. This is possible.

To derive the shear stress, the shear stress can be calculated from the following shear strain measurement data.

Referring to FIG. 4, the shear stress can be calculated from the shear strain measurement data using the following equations 1 and 2.

G: Shear elastic modulus, E: Elastic modulus, V: Poisson's ratio, ε(45): 45 degree direction strain, ε(135): 135 degree direction strain, γ: shear strain, τ: shear stress.

That is, the shear stress can be calculated using the values measured by the first strain gauge 110 and the second strain gauge 120, ε(45): strain value in the 45-degree direction and ε(135): strain value in the 135-degree direction.

Additionally, the shear force of the support portion can be derived from the maximum shear stress calculation formula through Equation 3.

Therefore, the shear force of the support can be derived from the maximum shear stress calculation formula.

The thrust is estimated based on the derived shear force by applying the force ratio value that can be derived from the results of FEA (Finite Element Analysis) and CFD (Computational Fluid Dynamics) analysis.

More specifically, the estimation method can be viewed as the same as the estimated value of the shear force of the inner steel support and the estimated value of the upper bearing force, and the shear force of the support (V _estimated ) = upper bearing force (F _bearing ). Through this, the shear force can be derived from the maximum shear stress calculation formula in Equation 3, and the thrust can be estimated by applying the force ratio value through FEA (Finite Element Analysis) and CFD (Computational Fluid Dynamics).

As shown in Table 1, the Force Ratio can be applied by deriving a coefficient value considering the wind direction and deriving a correlation through comparison of CFD-FEM results.

Additionally, the drag force estimation method using a strain gauge is the same as the thrust estimation process, but the factors are different.

Therefore, it is possible to estimate thrust force and drag force from shear stress.

Therefore, it is possible to calculate thrust force and drag force from the derived shear stress through the maximum shear stress formula.

In addition, changes in actual thrust and drag considering the wind direction can be identified by deriving a correlation from the analysis results of CFD (Computational Fluid Dynamics) and FEM (Finite Element Method).

This has the effect of making it possible to estimate thrust and drag due to wind from the operation of the Magnus rotor.

Referring to Figures 5 and 6, looking at the correlation, it is possible to estimate the correction coefficient through comparison of CFD-FEM results.

Figure 5 shows the reaction force values in the thrust and drag directions applying the operating load.

In addition, Figure 6 shows the shear stress values for each position at a certain height from the deck derived through FEA analysis results. In particular, Figure 6(a) is the value at the strain gauge position for thrust measurement, and Figure 6(b) is the drag force. Indicates the value at the strain gauge location for measurement.

As shown in Figure 6, it is stably measured at a certain height (H) of 8 to 12 m from the deck, and the most stable value is shown at a point of 10 m, so it is desirable to install a strain gauge at a point of 10 m.

Therefore, as shown in FIG. 7, a strain gauge (SG_thrust) for thrust measurement is set at 45 degrees Celsius on a vertical plane in the direction of movement of the ship at any point of the support at a height of 10 m from the deck of the ship. It can be placed at degrees and 135 degrees.

In addition, strain gauges (SG_darg) for drag force measurement can be placed at 45 degrees and 135 degrees on the plane perpendicular to the width direction of the ship at any point on the support at a height of 10 m from the ship's deck. You can.

In addition, considering that the strain gauges for measuring thrust and drag may fail, dummy strain gauges (DSG_thrust, DSG_drag) are placed on opposite sides.

Therefore, the method of estimating thrust and drag using the Magnus rotor of a ship according to the present invention includes a measurement step (S100) of measuring the deformation value of the support using at least four strain gauges, and the measurement step (S100) of measuring the deformation value of the ship using the measurement step. It includes an estimation step (S200) for estimating thrust and drag.

At least four strain gauges can be called a measuring unit (not shown), and an estimation unit (not shown) receives and calculates the measured values from the measuring unit to derive shear stress and calculates from the shear stress to estimate thrust and drag. ) may include.

The deformation value of the support is measured by at least four strain gauges, which are the measurement section, and the estimating section calculates and derives the shear stress from the deformation values measured by at least four strain gauges, and estimates the thrust and drag by calculating from the derived shear stress. do.

That is, the estimation step (S200) receives the strain value of the support portion through the first to fourth strange gauge values measured in the measurement step (S100), and calculates the shear stress from the received strain value to derive the shear stress. It may include a thrust and drag estimation step (S220) of estimating the thrust and drag from the maximum shear stress calculation formula from the shear stress derived through step (S210) and the shear stress derivation step (S210).

At this time, the thrust is estimated using the values measured through the first and second strain gauges arranged on a plane perpendicular to the direction of movement of the ship, and the third and fourth strain gauges arranged on a plane perpendicular to the width direction of the ship are used. It is characterized by estimating drag from the value measured through the method.

Therefore, according to the present invention, the driving of the Magnus rotor is controlled through a thrust and drag estimation method using the Magnus rotor of a ship, and the thrust and drag due to wind can be estimated from the operation of the Magnus rotor.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but rather to explain it, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted in accordance with the claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of the present invention.

10: Foundation
20: Support (Inner steel support)
110: first strain gauge (strain gauge)
120: Second strain gauge (strain gauge)
130: First dummy strain gauge
140: Second dummy strain gauge
210: Third strain gauge
220: Fourth strain gauge (strain gauge)
230: Third dummy strain gauge
240: Fourth dummy strain gauge

Claims (7)

In the thrust and drag estimation method using the ship's Magnus rotor,
It includes at least one Magnus rotor for driving a ship, and the ship is provided with a support part for supporting the Magnus rotor, and the support part is equipped with at least four strain gauges to estimate the thrust and drag of the Magnus rotor,
A measurement step of measuring the strain value of the support using the at least four strain gauges; and
It includes an estimation step of estimating the thrust and drag of the ship using the values measured through the measurement step;
The at least four strain gauges are,
It is arranged on the circumferential surface of the support part at a certain height from the deck, which is not affected by the lower bearing of the support part, and is arranged at an angle;
First and second strain gauges are provided on a surface perpendicular to the moving direction of the ship, and third and fourth strain gauges are provided on a surface perpendicular to the width direction of the ship;
The estimation step is,
Deriving shear stress from the values measured from the first and second strain gauges through the measurement step; and
A thrust and drag estimation method using a ship's Magnus rotor, comprising the step of calculating and estimating thrust and drag from the derived shear stress through the maximum shear stress formula. delete In claim 1,
The first and second strain gauges are attached to and arranged on supports in directions of 45 degrees and 135 degrees, and the third and fourth strain gauges are attached to and arranged in supports in directions of 45 degrees and 135 degrees. Thrust and drag estimation method using Magnus rotor. In claim 3,
The strain gauge attached to and disposed on the support portion is:
In consideration of gauge measurement failure, dummy strain gauges are additionally provided on opposite sides of the first and second strain gauges, and dummy strain gauges are provided on opposite sides of the third and fourth strain gauges. Thrust and drag estimation method using a ship's Magnus rotor, characterized in that it is provided. delete In claim 1,
The estimation step is,
Calculating and deriving shear stress from measurement data measured in a first strain gauge, and determining thrust from the derived shear stress through a maximum shear stress formula; and
Thrust using the ship's Magnus rotor, comprising the step of calculating and deriving the shear stress from the measurement data measured in the second strain gauge, and determining the drag from the derived shear stress through the maximum shear stress formula, and Drag force estimation method. In claim 1,
A method for estimating thrust and drag using a ship's Magnus rotor, characterized in that at least four strain gauges are arranged at a certain height of 8 to 12 meters from the deck, which is not affected by the lower bearing of the support.