JP2017166870A - Balance for wind tunnel test and wind tunnel test device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a balance for a wind tunnel test and a wind tunnel test device which suppress decrease in accuracy of measuring small force.SOLUTION: A balance 20 for a wind tunnel test includes: an extension part 22 extending in an extension direction A along such a direction that drag acts; a model attachment part 30; a wind tunnel fixing part 32; an opening part 42 provided on a lateral surface 41 of the extension part 22 between the model attachment part 30 and the wind tunnel fixing part 32; and a drag detection part 60 which is a tabular member provided inside the opening part 42, in which one lateral surface 60A and the other lateral surface 60B are fixed on an inner surface of the opening part 42, and whose surface has a drag fiber reinforced plastic (FRP) layer. When the length of fiber in the drag FRP layer is decomposed into a vector component in a drag first direction from one lateral surface 60A to the other lateral surface 60B and a vector component in a drag second direction orthogonal to the drag first direction, the total value of the drag second direction-vector components of the all fiber in the drag FRP layer is larger than the total value of the drag first direction-vector components.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a wind tunnel test balance and a wind tunnel test apparatus.

  A wind tunnel test may be used to measure the force acting on an operating aircraft or the like. In the wind tunnel test, a wind tunnel balance is attached to an aircraft model provided in the wind tunnel to generate an air flow in the wind tunnel. A load in three directions of drag, lift and lateral force and a moment in three directions of rolling moment, pitching moment, and yawing moment act on the model. Since the wind tunnel balance is fixed to the model, distortion occurs due to the forces (loads and moments) applied to the model in a plurality of directions. A strain gauge is attached to the wind tunnel balance, and the strain detected by the strain gauge is analyzed to calculate the forces acting on the model from multiple directions.

  For this wind tunnel balance, a high-rigidity metal member such as carbon steel was used. For example, Patent Document 1 describes a cylindrical wind tunnel balance.

Japanese Patent Laid-Open No. 10-9997

  Here, the force from a plurality of directions acting on the model has different sizes. For example, in order to increase the flight capability, the lift is designed to be large. The wind tunnel balance is designed to have high rigidity in order to measure a large force such as lift. However, in this case, the deformation with respect to a small force becomes minute, and the detection capability with respect to this small force may be reduced. If the rigidity is lowered to detect a small force, for example, the amount of deformation with respect to a large force component increases, and the amount of deformation with respect to the large force component becomes noise, which may reduce the detection accuracy of the small force.

  The present invention has been made in view of the above, and it is an object of the present invention to provide a wind tunnel balance and a wind tunnel testing apparatus that suppress a decrease in measurement accuracy of a small force among a plurality of directions acting on a model. To do.

  In order to solve the above-described problems and achieve the object, a wind tunnel test balance according to the present disclosure is a wind tunnel test balance that detects forces from a plurality of directions acting on a model arranged in a wind tunnel. The extension portion extending in the extending direction along the direction in which the drag acting on the model acts, the model attachment portion provided at one end of the extension portion and fixed to the model, and Provided at the other end of the extending portion and fixed to the wind tunnel, between the model mounting portion and the wind tunnel fixing portion, and provided on a side surface of the extending portion. An opening and a plate-like member provided inside the opening, wherein one side is fixed to a predetermined position on the inner surface of the opening, and the other side is the predetermined position on the inner surface of the opening Fixed to a location facing the direction extending across the extending direction from A drag detection unit provided on the surface with a drag FRP layer which is a fiber reinforced plastic layer, and the length of the fiber in the drag FRP layer is a direction from the one side surface toward the other side surface. When the vector component in the drag first direction and the vector component in the drag second direction orthogonal to the drag first direction are decomposed, the vector component in the drag second direction of all the fibers in the drag FRP layer The total value becomes larger than the total value of the vector components in the drag first direction.

  This wind tunnel test balance can increase the rigidity with respect to the tensile force, the torsional force, and the bending force and reduce the rigidity with respect to the shearing force in the drag detection unit. Therefore, this wind tunnel test balance can suppress a decrease in the measurement accuracy of the drag, which is a small force.

  In the wind tunnel test balance, the drag FRP layer includes a drag first direction layer in which the fibers extending in the drag first direction and a drag first layer in which the fibers extending in the drag second direction are arranged. It is preferable that a bi-directional layer is laminated, and the total length of the fibers of the drag second direction layer is larger than the total length of the fibers of the drag first direction layer. This wind tunnel test balance can increase the rigidity with respect to the tensile force, the torsional force, and the bending force and reduce the rigidity with respect to the shearing force in the drag detection unit. Therefore, this wind tunnel test balance can more suitably suppress a decrease in the measurement accuracy of the drag, which is a small force.

  In the wind tunnel test balance, it is preferable that the drag detection unit further includes a base material part that is a metal plate member, and the drag FRP layer is provided on a surface of the base material part. Since this wind tunnel test balance has a base material portion, it is possible to more suitably suppress a decrease in the measurement accuracy of the drag, which is a small force.

  In order to solve the above-described problems and achieve the object, a wind tunnel test apparatus according to the present disclosure is bonded to the balance of the wind tunnel test and the surface of the drag detection unit to detect distortion of the drag detection unit. A force detection element; and a control unit that calculates the drag based on a detection result of the force detection element. Since this wind tunnel test apparatus uses this wind tunnel test balance, it is possible to suppress a decrease in the measurement accuracy of the drag, which is a small force.

  In the wind tunnel test apparatus, the wind tunnel test balance is provided in the extension portion, and one end portion and the other end portion along the extension direction are fixed to the extension portion. The multi-force detector further includes a multi-force detector, and the force detection element is adhered to the surface of the multi-force detector to detect distortion of the multi-force detector, and the control unit is connected to the multi-force detector. Based on the detection result of the adhered force detection element, a force other than the drag acting on the model is calculated. In this wind tunnel testing device, a drag is detected by a drag detection unit, and a force other than the drag is detected by a multi-force detection unit at a location different from the drag detection unit. Therefore, this wind tunnel testing apparatus 1 can suppress a decrease in measurement accuracy of the force acting on the model.

  In the wind tunnel test balance, the extended portion is a fiber-reinforced plastic layer in which one end portion and the other end portion along the extending direction are fixed to the extended portion. A multi-force detection unit having a force FRP layer on the surface, and the length of the fibers in the multi-force FRP layer, the vector component of the multi-force first direction which is a direction along the extending direction, When decomposed into multi-force second direction vector components orthogonal to the multi-force first direction, the total value of the multi-force first direction vector components of all the fibers in the multi-force FRP layer is the multi-force first direction vector component. The force is preferably larger than the total value of the vector components in the second direction. This wind tunnel test balance can suppress a decrease in measurement accuracy of drag and rolling moment, which are small forces.

  In order to solve the above-described problems and achieve the object, a wind tunnel test balance according to the present disclosure is a wind tunnel test balance that individually measures loads from a plurality of directions acting on a model arranged in a wind tunnel. The extension portion extending in the extending direction along the direction in which the drag acting on the model acts, the model attachment portion provided at one end of the extension portion and fixed to the model, and A wind tunnel fixing portion provided at the other end portion of the extension portion and fixed to the wind tunnel; and one end portion and the other end portion provided in the extension portion along the extension direction. Is fixed to the extending portion, and has a multi-force detecting portion having a multi-strength FRP layer on the surface, which is a fiber reinforced plastic layer, and the length of the fibers in the multi-strength FRP layer is , A vector component of a multi-force first direction which is a direction along the extending direction, and the multi-force first direction In the multi-force second direction perpendicular to the multi-force vector, the total value of the multi-force first direction vector components of all the fibers in the multi-force FRP layer is the multi-force second direction. It becomes larger than the total value of the vector components.

  This wind tunnel test balance has high rigidity with respect to shearing force, tensile force, and bending force and low rigidity with respect to torsional force in the multi-force detection unit. Therefore, this wind tunnel test balance can suppress a decrease in measurement accuracy of the rolling moment, which is a small force.

  In the wind tunnel test balance, the multi-strength FRP layer includes a multi-strength first direction layer in which the fibers extending in the multi-strength first direction and the fibers extending in the multi-strength second direction are arranged. The multi-force second direction layers to be arranged are laminated, and the total value of the lengths of the fibers of the multi-force first direction layer is greater than the total value of the lengths of the fibers of the multi-force second direction layer. Is also preferably large. This wind tunnel test balance has high rigidity with respect to shearing force, tensile force, and bending force and low rigidity with respect to torsional force in the multi-force detection unit. Therefore, this wind tunnel test balance can more suitably suppress a decrease in the measurement accuracy of the rolling moment, which is a small force.

  In the wind tunnel test balance, it is preferable that the multi-force detecting portion further includes a base material portion that is a metal member, and the multi-force FRP layer is provided on a surface of the base material portion. Since this wind tunnel test balance has a base material portion, it is possible to more suitably suppress a decrease in measurement accuracy of the rolling moment, which is a small force.

  In order to solve the above-described problems and achieve the object, a wind tunnel test apparatus according to the present disclosure is bonded to the wind tunnel test balance and the surface of the multi-force detection unit, and the distortion of the multi-force detection unit is reduced. A force detection element to detect, and a control unit that calculates a rolling moment in a rotation direction about the extending direction acting on the model as a central axis based on a detection result of the force detection element. Since this wind tunnel test apparatus uses this wind tunnel test balance, it is possible to suppress a decrease in the measurement accuracy of the rolling moment, which is a small force.

  In the wind tunnel testing apparatus, the extending portion of the wind tunnel test balance has an opening on a side surface between the model mounting portion and the wind tunnel fixing portion, and is provided inside the opening. It is a plate-like member, and one side is fixed to a predetermined location on the inner surface of the opening, and the other side is along a direction intersecting the extending direction from the predetermined location on the inner surface of the opening. It further includes a drag detection unit fixed to an opposite location, the force detection element is also bonded to the surface of the drag detection unit to detect distortion of the drag detection unit, and the control unit includes the drag detection unit. It is preferable to calculate the drag acting on the model based on the detection result of the force detection element bonded to the detection unit. In this wind tunnel testing device, a drag is detected by a drag detection unit, and a force other than the drag is detected by a multi-force detection unit at a location different from the drag detection unit. Therefore, this wind tunnel test equipment can suppress the fall of the measurement precision of the force which acts on a model.

  ADVANTAGE OF THE INVENTION According to this invention, the fall of the measurement accuracy of a small force can be suppressed among the forces from several directions which act on a model.

FIG. 1 is a schematic diagram of a wind tunnel testing apparatus according to the first embodiment. FIG. 2 is an explanatory diagram for explaining the force acting on the model. FIG. 3 is a schematic diagram of a wind tunnel test balance according to the first embodiment. FIG. 4 is a schematic diagram of a drag detection unit according to the first embodiment. FIG. 5A is a schematic diagram of a drag first direction layer and a drag second direction layer in the first embodiment. FIG. 5B is a schematic diagram of a drag first direction layer and a drag second direction layer in the first embodiment. FIG. 6A is a schematic diagram illustrating another example of the drag first direction layer and the drag second direction layer. FIG. 6B is a schematic diagram illustrating another example of the drag first direction layer and the drag second direction layer. FIG. 7 is a schematic view of a wind tunnel test balance according to the second embodiment. FIG. 8 is a schematic diagram of a multi-force detection unit according to the second embodiment. FIG. 9A is a schematic diagram of a multi-force first direction layer and a multi-force second direction layer in the second embodiment. FIG. 9B is a schematic diagram of a multi-force first direction layer and a multi-force second direction layer in the second embodiment. FIG. 10A is a schematic diagram illustrating another example of the multi-force first direction layer and the multi-force second direction layer. FIG. 10B is a schematic diagram illustrating another example of the multi-force first direction layer and the multi-force second direction layer.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment, Moreover, when there are two or more embodiments, what comprises a combination of each Example is also included.

(First embodiment)
(Configuration of wind tunnel test equipment)
FIG. 1 is a schematic diagram of a wind tunnel testing apparatus according to the first embodiment. As shown in FIG. 1, the wind tunnel testing apparatus 1 according to the first embodiment includes a wind tunnel 10, a strut 12, a sting 14, a model 16, a force detection element 17, a control device 18 as a control unit, A wind tunnel test balance 20. The wind tunnel test apparatus 1 is an apparatus for wind tunnel testing in which an air flow W is generated in the wind tunnel 10 in which the model 16 is installed, and forces from a plurality of directions acting on the model 16 are measured. The wind tunnel test in the present embodiment is a test for measuring a plurality of types of forces acting on an aircraft in flight. However, the wind tunnel test is not limited to an aircraft, but may be a test that measures a plurality of types of forces on a measurement object on which forces from different directions, that is, a plurality of types of forces act. In the following description, the direction in which the wind tunnel 10 extends is the direction X, the direction orthogonal to the direction X, the direction orthogonal to the vertical direction is the direction Y, and the direction orthogonal to the direction X and the direction Y, that is, vertical Let the direction be direction Z.

  The wind tunnel 10 is a wind tunnel having a room 11 which is sealed and extends in the direction X. The struts 12 are columnar members that are fixed to the top and bottom in the direction Z of the room 11 and extend in the direction Z. The sting 14 is an axial member whose one end is fixed to the strut 12 and extends in the direction X. The sting 14 is provided at its other end with a fixing portion 14A to which the wind tunnel test balance 20 is fixed. The model 16 is a model of an object to be subjected to a wind tunnel test arranged in the wind tunnel 10. The model 16 is an aircraft model in this embodiment. A balance conduction hole 16 </ b> A is opened at the rear end of the model 16, that is, the end on the tail side. Here, if the direction from the rear end portion of the model 16 toward the front end portion is the model front direction PL, the balance conduction hole 16A extends from the rear end portion of the model 16 to the inside of the model 16 in the model front direction. Open along PL. A fixing portion 16B is provided at the bottom of the balance conduction hole 16A.

  The wind tunnel test balance 20 has an extending portion 22 that is a shaft-like member extending along the extending direction A. A model attachment portion 30 is provided at one end of the extension portion 22. A wind tunnel fixing portion 32 is provided at the other end of the extending portion 22. The wind tunnel test balance 20 is mounted in the balance conduction hole 16A. In the wind tunnel test balance 20, the model mounting portion 30 is inserted into the fixing portion 16 </ b> B that opens, and is fixed to the model 16. Since the diameter of the wind tunnel test balance 20 is smaller than the diameter of the balance conduction hole 16 </ b> A, the wind tunnel test balance 20 does not contact the model 16 at a place other than the model mounting portion 30. In the wind tunnel test balance 20, the wind tunnel fixing portion 32 is inserted into the fixing portion 14 </ b> A that opens, and is fixed to the sting 14. That is, the wind tunnel test balance 20 is fixed to the wind tunnel 10 by the wind tunnel fixing portion 32. The detailed configuration of the wind tunnel test balance 20 will be described later.

  In the wind tunnel test apparatus 1, the model 16 is thus fixed inside the wind tunnel 10 via the wind tunnel test balance 20. The model 16 is fixed inside the wind tunnel 10 so that the model front direction PL is along the direction X, more specifically, in a direction opposite to the direction X. Further, the wind tunnel test balance 20 is fixed inside the wind tunnel 10 so that the extending direction A that is the axial direction is along the direction X that is the direction in which the drag force FX works.

  The force detection element 17 is a strain gauge attached to the surface of the wind tunnel test balance 20. The force detection element 17 detects distortion (deformation) of the wind tunnel test balance 20. The control device 18 is a device that controls the wind tunnel testing device 1. The control device 18 controls an air flow generation unit (not shown) inside the wind tunnel 10 to generate an air flow W in the wind tunnel 10. In FIG. 1, the air flow W flows along the direction X inside the wind tunnel 10, but the flow direction, the flow velocity, the flow rate, and the like are controlled by the control device 18 so as to be changeable. Further, the control device 18 acquires information on the distortion of the wind tunnel test balance 20 detected by the force detection element 17. The control device 18 calculates the force acting on the wind tunnel test balance 20 from the distortion of the wind tunnel test balance 20. The wind tunnel test balance 20 is fixed to the model 16. Therefore, it can be said that the control device 18 calculates the force acting on the model 16 from the distortion of the surface of the wind tunnel test balance 20.

  Hereinafter, the force acting on the model 16 will be described. FIG. 2 is an explanatory diagram for explaining the force acting on the model. As shown in FIG. 2, the center of gravity of the model 16 is a center of gravity O, a plane along the center of gravity O, and a plane perpendicular to the direction X is a plane P. When the model 16 receives the airflow W, three types of loads, ie, a drag force FX, a lateral force FY, and a lift force FZ, are applied from different directions. The drag force FX is a load that acts on the model 16 along the direction X. That is, the drag FX is a resistance that works opposite to the aircraft traveling direction. The lateral force FY is a load that acts on the model 16 along the direction Y. The lateral force FY is a force that moves the aircraft in the lateral direction. The lift force FZ is a load that acts on the model 16 along the direction Z. The lift FZ is a force that lifts the aircraft. Further, when the model 16 receives the airflow W, three types of moments from different directions, ie, a rolling moment MX, a pitching moment MY, and a yawing moment MZ, act. The rolling moment MX is a moment acting on the model 16 along the rotation direction with the direction X as the rotation axis. The rolling moment MX is a force that rotates the aircraft about the traveling direction as a rotation axis. The pitching moment MY is a moment acting along the rotation direction with the direction Y as the rotation axis. The pitching moment MY is a force that moves the tip of the aircraft up and down. The yawing moment MZ is a moment acting along the rotation direction with the direction Z as the rotation axis. The yawing moment MZ is a force that turns the aircraft.

  Thus, when the model 16 receives the airflow W, a plurality of forces (loads and moments) from different directions are applied. The wind tunnel test balance 20 is distorted according to the force acting on these models 16. The wind tunnel test apparatus 1 detects this distortion by the force detection element 17 and calculates the values of these forces from the distortion by the control apparatus 18, respectively.

  Since the aircraft is designed to have low resistance, the drag FX has a small force. In other words, the drag FX has a small load, and the lateral force FY and the lift FZ have a large load. Also, the rolling moment MX has a small force. That is, the rolling moment MX has a small moment, and the pitching moment MY and the yawing moment MZ have large moments. Therefore, even when the wind tunnel balance 20 receives the same air flow W, the distortion generated by the drag FX and the rolling moment MX is reduced, and is generated by the lateral force FY, the lift force FZ, the pitching moment MY, and the yawing moment MZ. Distortion increases.

  Hereinafter, the configuration of the wind tunnel test balance 20 will be described. FIG. 3 is a schematic diagram of a wind tunnel test balance according to the first embodiment. As described above, the wind tunnel test balance 20 has the extending portion 22 that is a shaft-like member extending along the extending direction A. The extension part 22 is provided with a model attachment part 30, a wind tunnel fixing part 32, an opening part 42, and multi-force detection parts 50A and 50B. The extending portion 22 is a shaft member made of metal such as carbon steel, and is a columnar member in the present embodiment. Hereinafter, a direction orthogonal to the extending direction A is referred to as a direction B, and a direction orthogonal to the extending direction A and the direction B is referred to as a direction C.

  The model attaching portion 30 is provided at one end portion along the extending direction A of the extending portion 22. The model mounting portion 30 is provided by processing one end of the extending portion 22 into a truncated cone shape. As described above, the model attachment portion 30 is inserted into the fixing portion 16B and fixed to the model 16. The wind tunnel fixing portion 32 is provided at the other end portion along the extending direction A of the extending portion 22. The wind tunnel fixing portion 32 is provided by processing the other end of the extending portion 22 into a truncated cone shape. As described above, the wind tunnel fixing portion 32 is inserted into the fixing portion 14A and fixed to the wind tunnel 10. When the wind tunnel test balance 20 is fixed to the model 16 and the wind tunnel 10, the extending direction A is along the direction X, the direction B is along the direction Y, and the direction C is along the direction Z.

  The opening 42 is provided between the model mounting portion 30 and the wind tunnel fixing portion 32 in the extending direction A and on the side surface 41 of the extending portion 22. The opening 42 penetrates the side surface 41 along the direction perpendicular to the extending direction A, here the direction B. However, the opening 42 is not limited to passing through the side surface 41 along the direction B as long as it is an opening provided on the side surface 41. The opening 42 only needs to penetrate the side surface 41 along the direction intersecting the extending direction A. The opening 42 may have a bottom surface without penetrating the side surface 41.

  The multi-force detecting unit 50A is provided in a partial region of the extending part 22 along the extending direction A between the model attaching part 30 and the opening part 42. The multi-force detecting unit 50A is provided by processing a partial region of the side surface 41 of the extending portion 22 and a region opposite to the partial region into a plane. In other words, in the multi-force detecting unit 50A, one end 51A along the extending direction A is fixed to the model attaching part 30 side of the extending part 22, and the other end 52A is extended to the extending part 22. It is being fixed to the wind tunnel fixing | fixed part 32 side.

  The multi-force detection unit 50B is provided in a partial region of the extending part 22 along the extending direction A between the opening 42 and the wind tunnel fixing part 32. The multi-force detecting unit 50B is provided by processing a part of the side surface 41 of the extending part 22 and a region opposite to the part of the region into a flat surface. In other words, in the multi-force detecting unit 50B, one end 51B along the extending direction A is fixed to the opening 42 side of the extending part 22, and the other end 52B is a wind tunnel of the extending part 22. It is fixed to the fixed portion 32 side. In the present embodiment, the extending portion 22 is provided with the multi-force detector 50A and the multi-force detector 50B, but only one of the multi-force detector 50A and the multi-force detector 50B is provided. May be provided. Hereinafter, when the multi-power detection unit 50A and the multi-power detection unit 50B are not distinguished from each other, they are referred to as the multi-power detection unit 50. A plurality of force detection elements 17 are bonded to the surface (planar portion) of the multi-force detection unit 50.

  In addition, a drag detection unit 60 is provided in the opening 42. The drag detection unit 60 is a plate-like member provided inside the opening 42. One side surface 60 </ b> A of the drag detection unit 60 is fixed to the inner surface 42 </ b> A of the opening 42. Further, in the drag detection unit 60, the other side surface 60B is fixed to the inner surface 42B facing the inner surface 42A of the opening 42 along the direction C. The surface 60C of the drag detection unit 60 is provided along a plane perpendicular to the extending direction A. However, in the drag detection unit 60, one side surface 60A is fixed to a predetermined location on the inner surface of the opening 42, and the other side surface 60B intersects the extending direction A from the predetermined location on the inner surface of the opening 42. It is only necessary to be fixed at a position facing along. The force detection element 17 is bonded to the surface 60D of the drag detection unit 60 and the surface 60D which is the surface opposite to the surface 60C.

  FIG. 4 is a schematic diagram of a drag detection unit according to the first embodiment. As shown in FIG. 4, the drag detection unit 60 includes a base material part 62 and a drag FRP layer 64. The base material part 62 is a metal plate-like member such as carbon steel. The base material part 62 is formed by leaving only the part of the base material part 62 when the extended part 22 is processed and the opening 42 is provided. That is, the base material part 62 is a member integrated with the extending part 22. However, the base material portion 62 is a plate-like member that is separate from the extending portion 22, and one side surface 60 </ b> A and the other side surface 60 </ b> B may be fixed to the inner surface of the opening 42.

  The drag FRP layer 64 is a layer of fiber reinforced plastic (FRP) provided on the surface of the base material portion 62. That is, the drag FRP layer 64 is a layer in which a plurality of fibers Fi are fixed with resin. The drag FRP layer 64 in the present embodiment is a carbon fiber reinforced plastic layer, and the fibers Fi are carbon fibers. However, the fiber Fi may be glass fiber, for example. The drag FRP layer 64 only needs to have anisotropy in which the strength of the fibers Fi is higher than that of the base resin and the strength in the extending direction of the fibers Fi is high. The drag FRP layer 64 in the present embodiment is a laminate in which a plurality of fiber-reinforced plastic sheet-like members are stacked. The drag FRP layer 64 includes a drag first direction layer 66A and a drag second direction layer 66B.

  FIG. 5A is a schematic diagram of a drag first direction layer and a drag second direction layer in the first embodiment. FIG. 5A shows a sheet-like state before the drag first direction layer 66 </ b> A and the drag second direction layer 66 </ b> B are wound around the base material part 62. As shown in FIG. 5A, the drag first direction layer 66A is a fiber-reinforced plastic sheet-like member in which a plurality of fibers Fi are arranged and extend in the same direction. The drag second direction layer 66B is a fiber-reinforced plastic sheet-like member in which a plurality of fibers Fi are arranged in the same direction and extend. That is, the drag first direction layer 66A and the drag second direction layer 66B are anisotropic FRP sheets. The direction in which the fibers Fi of the drag first direction layer 66A extend is different from the direction in which the fibers Fi of the drag second direction layer 66B extend. The drag FRP layer 64 is a laminate in which the sheet-like drag first direction layer 66A and the drag second direction layer 66B are stacked. As shown in FIG. 4, the drag FRP layer 64 is wound around the base material part 62 with the direction C as the central axis, and is crimped and fixed to the base material part 62. Moreover, as shown in FIG. 4, the surface of the drag FRP layer 64 is a drag second direction layer 66B.

  FIG. 5B is a schematic diagram of a drag first direction layer and a drag second direction layer in the first embodiment. FIG. 5B shows the drag first direction layer 66 </ b> A and the drag second direction layer 66 </ b> B when the drag FRP layer 64 is attached to the base material portion 62. As shown in FIG. 5B, when the drag first direction layer 66A is attached to the base material portion 62, the fiber Fi extends along the drag first direction that is a direction from one side surface 60A toward the other side surface 60B. However, there are multiple arrays. Specifically, the drag first direction layer 66 </ b> A extends along the direction C. Further, when the drag second direction layer 66B is attached to the base material portion 62, a plurality of fibers Fi extending along the drag second direction which is a direction orthogonal to the drag first direction (direction C) are arranged. ing. Specifically, the drag second direction layer 66 </ b> B has a plurality of fibers Fi extending along the direction B on the surface 60 </ b> C of the drag detection unit 60, and a plurality of fibers Fi on the side surface 67 of the drag detection unit 60. It extends along the extending direction A.

  In the drag FRP layer 64, the number of the drag second direction layers 66B stacked is larger than the number of the drag first direction layers 66A stacked. That is, in the drag FRP layer 64, the total length of all the fibers Fi along the drag second direction (the total value of the lengths of all the fibers Fi of the drag second direction layer 66B) is the drag first direction. Is greater than the total length of all the fibers Fi (total length of all the fibers Fi of the drag first direction layer 66A). In addition, the number of layers of the drag second direction layer 66B increases as the drag FRP layer 64 moves toward the surface. For example, the drag FRP layer 64 includes a first laminated portion on the surface side where a plurality of drag first direction layers 66A and a drag second direction layer 66B are laminated, a plurality of drag first direction layers 66A and a drag second. Consider a case in which the direction layer 66B is divided into the second stacked portion on the base material portion 62 side where the direction layer 66B is stacked. In this case, the ratio of the number of layers of the drag second direction layer 66B to the number of layers of the drag first direction layer 66A is larger in the first stacked portion than in the second stacked portion. In other words, the ratio of the total value of the lengths of all the fibers Fi along the second direction of the drag to the total value of the lengths of all the fibers Fi along the first direction of the drag is higher in the first laminated portion. It is larger than two laminated parts.

(Measuring method)
Next, a method for measuring the force acting on the model 16 by the wind tunnel testing apparatus 1 configured as described above will be described. The wind tunnel test balance 20 is distorted by the force acting on the model 16 when the airflow W is generated. The force detection element 17 adhered to the surface of the multi-force detection unit 50 detects distortion of the multi-force detection unit 50 when the airflow W is generated. The control device 18 calculates a lateral force FY, a lift force FZ, a rolling moment MX, a pitching moment MY, and a yawing moment MZ acting on the model 16 based on the distortion of the multi-force detection unit 50. That is, the multi-force detection unit 50 is a detection unit that detects a plurality of types of forces (for example, a rolling moment MX) other than the drag force FX acting on the model 16 due to distortion. The force detection element 17 adhered to the surface of the multi-force detection unit 50 is a detection element that detects distortion corresponding to a plurality of types of forces (for example, a rolling moment MX) other than the drag FX acting on the model 16. .

  The force detection element 17 is provided for detecting the lateral force FY, the lift force FZ, the rolling moment MX, the pitching moment MY, and the yawing moment MZ. Specifically, four force detection elements 17 are provided for detecting each force. That is, a total of 20 force detection elements 17 are bonded to the surface of the multi-force detection unit 50. The four force detection elements 17 for detecting one force are connected as a Wheatstone bridge circuit each having a resistance to reduce the influence of distortion components corresponding to other forces.

  The control device 18 is based on the bending deformation amount (bending strain amount), the tensile deformation amount (tensile strain amount), and the shear deformation amount (shear strain amount) with respect to the axis along the extending direction A of the multi-force detection unit 50. Lateral force FY, lift force FZ, pitching moment MY, and yawing moment MZ are calculated. The control device 18 calculates the rolling moment MX based on the torsional deformation amount (torsional strain amount) with respect to the axis along the extending direction A of the multi-force detection unit 50.

  The force detection element 17 is also bonded to the surfaces 60C and 60D of the drag detection unit 60. The force detection element 17 provided in the drag detection unit 60 detects distortion of the drag detection unit 60 when the airflow W is generated. The control device 18 calculates the drag FX acting on the model 16 based on the distortion of the drag detection unit 60. In other words, the drag detection unit 60 is a detection unit that detects only the drag FX among a plurality of forces acting on the model 16 due to distortion. The force detection element 17 adhered to the surface of the drag detection unit 60 is a detection element that detects a strain corresponding to the drag FX among the forces acting on the model 16.

  A total of four force detection elements 17 are provided on the surfaces 60 </ b> C and 60 </ b> D of the drag detection unit 60. The four force detection elements 17 are connected as a Wheatstone bridge circuit each having a resistance, and reduce the influence of distortion components corresponding to forces other than the drag force FX.

  The control device 18 calculates the drag FX based on the shear deformation amount (shear strain amount) that acts on the surface of the drag detection unit 60. When distortion of components other than shear (for example, bending, tension, torsion, etc.) occurs in the drag detection unit 60, the force detection element 17 may also detect the distortion. In this case, since the control device 18 calculates the drag FX based on the distortion of components other than the shear, the measurement accuracy of the drag FX may be reduced. On the other hand, when the rigidity is increased by increasing the plate thickness in order to suppress the strain other than the shear, the shear deformation amount itself is also decreased, and the measurement accuracy of the drag FX may be decreased. In particular, since the drag FX, that is, the force for exerting shear deformation is small, the measurement accuracy of the drag FX is likely to be lowered. However, the drag detection unit 60 according to the first embodiment uses the drag FRP layer 64 to increase the stiffness against other strains while keeping the stiffness against shear strain low. Thereby, the drag detection unit 60 suppresses a decrease in measurement accuracy of the drag FX. Hereinafter, a specific description will be given with reference to FIG. 5B.

  As shown in FIG. 5B, a shear stress around the direction C acting on the drag detection unit 60, that is, a force causing shear strain is defined as a shear force S1. A tensile stress about the direction C acting on the drag detecting unit 60, that is, a force causing a tensile strain is defined as a tensile force S2. Further, the torsional stress about the direction C acting on the drag detecting unit 60, that is, the force causing the torsional strain is defined as torsional force S3. Further, a bending stress with the direction C acting on the drag detecting unit 60 as an axis, that is, a force causing a bending distortion is defined as a bending force S4.

  As shown in FIG. 5B, in the drag first direction layer 66A, a plurality of fibers Fi extend along the drag first direction, that is, the direction C. Accordingly, the resistance first direction layer 66A has higher rigidity against the tensile force S2 that pulls the fiber Fi and the bending force S4 that tries to bend the fiber Fi. On the other hand, in the drag second direction layer 66B, a plurality of fibers Fi extend in the drag second direction, that is, in the extending direction A and the direction B orthogonal to the direction C. Accordingly, the resistance second direction layer 66B has higher rigidity with respect to the twisting force S3 that tries to bend the fiber Fi. Accordingly, the resistance detection unit 60 has higher rigidity with respect to the tensile force S2, the torsional force S3, and the bending force S4. Note that the drag first direction layer 66A, which has higher rigidity against the tensile force S2 and the bending force S4, has a smaller number of layers than the drag second direction layer 66B. However, the fiber Fi has high strength against tension and bending. Therefore, if the drag detecting unit 60 has the drag first direction layer 66A having the fibers Fi extending along the direction C, the rigidity against the tensile force S2 and the bending force S4 is small even if the number is small. Can be maintained.

  On the other hand, since the shear force S1 acts in a direction in which the resin between the fibers Fi is separated, the drag second direction layer 66B has low rigidity with respect to the shear force S1. The drag detecting unit 60 has a large number of stacked drag second direction layers 66B. That is, the resistance detection unit 60 has more fibers Fi extending in the drag second direction (extending direction A, direction B) than fibers Fi extending in the drag first direction (direction C). Therefore, the drag detection unit 60 can reduce the rigidity against the shear force S1.

  As described above, the drag detection unit 60 has the drag FRP layer 64 that has high rigidity with respect to the tensile force S2, the torsional force S3, and the bending force S4, and lowers the rigidity with respect to the shearing force S1. Therefore, even when the drag detection unit 60 generates the air flow W under the same conditions, the shear strain increases and other strains decrease. Therefore, the wind tunnel testing apparatus 1 can suppress a decrease in measurement accuracy of the drag FX, which is a small force.

  6A and 6B are schematic views showing other examples of the drag first direction layer and the drag second direction layer. In the drag first direction layer 66A according to the first embodiment, a plurality of fibers Fi extend in the drag first direction, that is, in the direction C. Similarly, in the drag second direction layer 66B, the plurality of fibers Fi extend along the drag second direction, that is, the direction perpendicular to the direction C. However, as shown in FIG. 6A, the drag first direction layer 66A does not have to have a plurality of fibers Fi extending along the drag first direction, and the drag second direction layer 66B has a plurality of fibers. Fi may not extend along the drag second direction. A vector V1 in FIG. 6A is a vector obtained by decomposing the length of the fiber Fi into vector components along the first drag direction, that is, the direction C. A vector V2 in FIG. 6A is a vector obtained by decomposing the length of the fiber Fi into vector components in the second direction of the drag, that is, in a direction orthogonal to the direction C. The drag FRP layer 64 includes a drag first direction layer 66A and a drag second direction layer 66B in which the fibers Fi extend in different directions, and the sum of the vectors V2 of all the fibers Fi in the drag FRP layer 64. It is sufficient that the value is larger than the total value of the vectors V1 of all the fibers Fi in the drag FRP layer 64. When the total value of the vectors V2 of all the fibers Fi in the drag FRP layer 64 is larger than the sum of the vectors V1, the drag FRP layer 64 has rigidity with respect to the tensile force S2, the torsional force S3, and the bending force S4. It is high and the rigidity with respect to the shearing force S1 can be reduced.

  Further, as shown in FIG. 6B, the drag FRP layer 64 does not have a mutually different layer of the drag first direction layer 66A and the drag second direction layer 66B, and a plurality of one type of FRP layers 66 are laminated. Also good. The FRP layer 66 includes a plurality of fibers FiA extending in the same direction and a plurality of fibers FiB extending in a direction different from the fibers FiA. Further, the FRP layer 66 may have only a plurality of fibers FiA extending in the same direction. Even in this case, the drag FRP layer 64 only needs to have the total value of the vectors V2 of all the fibers Fi in the drag FRP layer 64 larger than the sum of the vectors V1 of all the fibers Fi in the drag FRP layer 64. Further, the drag FRP layer 64 may be a single layer of the FRP layer 66.

  As described above, the wind tunnel test balance 20 according to the first embodiment detects forces from a plurality of directions acting on the model 16 provided in the wind tunnel 10. The wind tunnel test balance 20 includes an extension part 22, a model attachment part 30, a wind tunnel fixing part 32, an opening part 42, and a drag detection part 60. The extending part 22 extends in the extending direction A along the direction X in which the drag FX works. The model attaching part 30 is provided at one end of the extending part 22 and is fixed to the model 16. The wind tunnel fixing portion 32 is provided at the other end of the extending portion 22 and is fixed to the wind tunnel 10. The opening 42 is provided between the model mounting portion 30 and the wind tunnel fixing portion 32 and on the side surface 41 of the extending portion 22. The drag detection unit 60 is a plate-like member provided inside the opening 42. In the drag detection unit 60, one side surface 60 </ b> A is fixed to a predetermined location on the inner surface of the opening 42, and the other side surface 60 </ b> B extends along a direction intersecting the extending direction A from the predetermined location on the inner surface of the opening 42. A drag FRP layer 64, which is a fiber reinforced plastic layer, is provided on the surface. Here, the length of the fiber Fi in the drag FRP layer 64 is determined based on the vector component V1 in the drag first direction, which is the direction from the one side surface 60A toward the other side surface 60B, and the drag second direction orthogonal to the drag first direction. It decomposes into a directional vector component V2. In the drag FRP layer 64, the total value of the vector components V2 of all the fibers Fi in the drag FRP layer 64 is larger than the total value of the vector components V1.

  In the wind tunnel test balance 20, the total value of the vectors V <b> 2 of all the fibers Fi in the drag FRP layer 64 is larger than the total value of the vectors V <b> 1 of all the fibers Fi in the drag FRP layer 64. Therefore, the wind tunnel test balance 20 has high rigidity with respect to the tensile force S2, the torsional force S3, and the bending force S4, and can have low rigidity with respect to the shearing force S1. Therefore, the wind tunnel test balance 20 can suppress a decrease in measurement accuracy of the drag FX, which is a small force.

  The drag FRP layer 64 is formed by laminating a drag first direction layer 66A in which the fibers Fi extend in the drag first direction and a drag second direction layer 66B in which the fibers Fi extend in the drag second direction. . The number of layers of the drag second direction layer 66B is larger than the number of layers of the drag first direction layer 66A. In the drag FRP layer 64, the total length of the fibers Fi of the drag second direction layer 66B is larger than the total length of the fibers Fi of the drag first direction layer 66A. Therefore, the wind tunnel test balance 20 has high rigidity with respect to the tensile force S2, the torsional force S3, and the bending force S4, and can have low rigidity with respect to the shearing force S1. Therefore, this wind tunnel test balance 20 can more suitably suppress a decrease in measurement accuracy of the drag FX, which is a small force.

  In addition, the drag detection unit 60 further includes a base material portion 62 that is a metal plate member, and a drag FRP layer 64 is provided on the surface of the base material portion 62. Since the drag detection unit 60 includes the base material part 62, it is possible to more suitably suppress a decrease in measurement accuracy of the drag FX, which is a small force. However, the drag detection unit 60 may not include the base material unit 62 but may include only the drag FRP layer 64.

  The wind tunnel test apparatus 1 according to the first embodiment includes a wind tunnel test balance 20, a force detection element 17, and a control device 18 (control unit). The force detection element 17 is adhered to the surface of the drag detection unit 60, that is, the surface of the drag FRP layer 64, and detects distortion of the drag detection unit 60. The control device 18 calculates the drag FX based on the detection result of the force detection element 17. Since this wind tunnel test apparatus 1 uses the wind tunnel test balance 20, it is possible to suppress a decrease in measurement accuracy of the drag FX, which is a small force.

  In addition, the wind tunnel test balance 20 is provided in the extending portion 22, and one end portion along the extending direction A and the other end portion are fixed to the extending portion 22. 50. The force detection element 17 is also adhered to the surface of the multi-force detection unit 50 to detect distortion of the multi-force detection unit 50. The control device 18 calculates a force other than the drag force FX acting on the model 16 based on the detection result of the force detection element 17 adhered to the multi-force detection unit 50. In the wind tunnel testing device 1, the drag detection unit 60 detects the drag FX, and the multi-force detection unit 50 at a location different from the drag detection unit 60 detects a force other than the drag FX. Therefore, this wind tunnel testing apparatus 1 can suppress a decrease in measurement accuracy of the force acting on the model 16. In addition, although the multiple force detection part 50 in this embodiment detects multiple types of force other than the drag FX, you may detect at least 1 type of force other than the drag FX as a force detection part.

(Second Embodiment)
Next, a second embodiment will be described. The wind tunnel test balance 20a according to the second embodiment is different from the first embodiment in that a fiber plastic layer is provided in the multi-force detection unit 50a. In the second embodiment, description of portions having the same configuration as that of the first embodiment is omitted.

  FIG. 7 is a schematic view of a wind tunnel test balance according to the second embodiment. As shown in FIG. 7, the wind tunnel test balance 20a according to the second embodiment includes multi-force detectors 50Aa and 50Ba and a drag detector 60a. The drag detection unit 60 a is a plate-like member provided inside the opening 42. The drag detection unit 60a is a metal plate-like member such as carbon steel, and does not have the drag FRP layer 64 unlike the first embodiment. The method of fixing the drag detection unit 60a to the opening 42 is the same as in the first embodiment.

  The multi-force detection unit 50Aa is provided between the model attachment unit 30 and the opening 42 and extends along the extending direction A. In the multi-force detecting unit 50A, one end 51Aa along the extending direction A is fixed to the model attaching part 30 side of the extending part 22, and the other end 52Aa is the opening 42 of the extending part 22. It is fixed on the side. The multi-force detecting unit 50Ba is provided between the opening 42 and the wind tunnel fixing unit 32 and extends along the extending direction A. In the multi-force detecting unit 50Ba, one end 51Ba along the extending direction A is fixed to the opening 42 side of the extending part 22, and the other end 52Ba is the wind tunnel fixing part 32 of the extending part 22. It is fixed on the side. In the present embodiment, the multi-power detection unit 50Aa and the multi-power detection unit 50Ba are provided. However, only one of the multi-power detection unit 50Aa and the multi-power detection unit 50Ba may be provided. . Hereinafter, when the multi-power detection unit 50Aa and the multi-power detection unit 50Ba are not distinguished, they are described as the multi-power detection unit 50a. In addition, one end of the multi-force detection unit 50a is described as one end 51a, and the other end is described as the other end 52a.

  FIG. 8 is a schematic diagram of a multi-force detection unit according to the second embodiment. As shown in FIG. 8, the multi-force detector 50 a includes a base material portion 72 and a multi-force FRP layer 74. The base material part 72 is a metal plate-like member such as carbon steel. The base material portion 72 is formed by processing the extension portion 22 so that only the portion of the base material portion 72 has a small width. That is, the base material part 72 is a member integrated with the extending part 22. However, the base material portion 72 is a separate member from the extending portion 22, and one end portion and the other end portion along the extending direction A are fixed to the extending portion 22. Also good.

  The multi-strength FRP layer 74 is a fiber reinforced plastic layer provided on the surface of the base material portion 72. The multi-strength FRP layer 74 in the present embodiment is a carbon fiber reinforced plastic layer, and the fibers Fi are carbon fibers. However, the fiber Fi may be glass fiber, for example. The multistrength FRP layer 74 only needs to have anisotropy in which the strength of the fibers Fi is higher than that of the resin of the base material and the strength in the extending direction of the fibers Fi is high. The multi-strength FRP layer 74 in the present embodiment is a laminate in which a plurality of fiber-reinforced plastic sheet-like members are laminated. The multi-strength FRP layer 74 includes a multi-strength first direction layer 76A and a multi-strength second direction layer 76B.

  FIG. 9A is a schematic diagram of a multi-force first direction layer and a multi-force second direction layer in the second embodiment. FIG. 9A shows a sheet-like state before the multi-strength first direction layer 76 </ b> A and the multi-strength second direction layer 76 </ b> B are wound around the base material portion 72. As shown in FIG. 9A, the multi-strength first direction layer 76A is a fiber-reinforced plastic sheet-like member in which a plurality of fibers Fi are arranged and extend in the same direction. The multi-strength second direction layer 76B is a fiber-reinforced plastic sheet-like member in which a plurality of fibers Fi are arranged in the same direction and extend. The direction in which the fibers Fi of the multi-force first direction layer 76A extend is different from the direction in which the fibers Fi of the multi-force second direction layer 76B extend. The multi-strength FRP layer 74 is a laminate in which the sheet-like multi-strength first direction layer 76A and multi-strength second direction layer 76B are laminated. As shown in FIG. 8, the multi-strength FRP layer 74 is wound around the base material part 72 with the extending direction A as the central axis, and is fixed to the base material part 72 by pressure bonding. Further, as shown in FIG. 8, the multi-strength first direction layer 76A has a multi-strength first direction layer 76A.

  FIG. 9B is a schematic diagram of a multi-force first direction layer and a multi-force second direction layer in the second embodiment. FIG. 9B shows the multi-force first direction layer 76 </ b> A and the multi-force second direction layer 76 </ b> B when the multi-strength FRP layer 74 is attached to the base material portion 72. As shown in FIG. 9B, when the multi-strength first direction layer 76A is attached to the base material portion 72, the multi-strength first direction layer 76A extends along the multi-strength first direction that is a direction from one end 51a toward the other end 52a. A plurality of existing fibers Fi are arranged. Specifically, in the multi-strength first direction layer 76A, a plurality of fibers Fi extend in the extending direction A. Further, when the multi-strength second direction layer 76B is attached to the base material portion 72, the fiber Fi extends along the multi-strength second direction which is a direction orthogonal to the multi-strength first direction (extending direction A). However, there are multiple arrays. Specifically, the multi-force second direction layer 76B has a plurality of fibers Fi extending along the direction C on the side surface 77 of the multi-force detector 50a, and a plurality of fibers Fi on the side surface 78 of the multi-force detector 50a. The fibers Fi extend along the direction B.

  In the multi-strength FRP layer 74, the number of multi-strength first direction layers 76A stacked is larger than the number of multi-strength first direction layers 76B stacked. Therefore, the multi-strength FRP layer 74 has a total length of all the fibers Fi along the multi-strength first direction (a total value of the lengths of the fibers Fi of the multi-strength first direction layer 76A). It is larger than the total length of all the fibers Fi along the two directions (the total length of the fibers Fi of the multi-strength second direction layer 76B). Further, the multi-strength FRP layer 74 has a larger number of multi-strength first direction layers 76A as it goes to the surface. For example, the multi-strength FRP layer 74 includes a first laminated portion on the surface side where a plurality of multi-strength first direction layers 76A and a multi-strength second direction layer 76B are laminated, and a plurality of multi-strength first direction layers 76A. And the second laminated portion on the base material portion 72 side where the multi-strength second direction layer 76B is laminated is considered. In this case, the ratio of the number of stacked multi-strength first direction layers 76A to the number of stacked multi-strength second direction layers 76B is larger in the first stacked portion than in the second stacked portion. In other words, the ratio of the total value of the lengths of all the fibers Fi along the multi-force first direction to the total value of the lengths of all the fibers Fi along the multi-force second direction is the direction of the first laminated portion. Is larger than the second stacked portion.

  Here, as described above, the control device 18 performs the bending deformation amount (bending strain amount), the tensile deformation amount (tensile strain amount), and the shear deformation amount with respect to the axis along the extending direction A of the multi-force detection unit 50a. Based on (shear strain amount), lateral force FY, lift force FZ, pitching moment MY, and yawing moment MZ are calculated. The control device 18 calculates the rolling moment MX based on the torsional deformation amount (torsional strain amount) with respect to the axis along the extending direction A of the multi-force detection unit 50. That is, the rolling moment MX is smaller than other forces detected by the multi-force detector 50a.

  As shown in FIG. 9B, in the multi-strength first direction layer 76A, a plurality of fibers Fi extend along the multi-strength first direction, that is, the extending direction A. Accordingly, the multi-strength first direction layer 76A has higher rigidity with respect to the tensile force S2 that tries to pull the fiber Fi, the shear force S1 that tries to bend the fiber Fi, and the bending force S4. Further, the torsional force S3 acts on the multi-strength first direction layer 76A in a direction that separates the layers, that is, the stacked multi-strength first direction layer 76A and other layers. Accordingly, the multi-strength first direction layer 76A has low rigidity against the torsional force S3.

  As described above, the multi-force detecting unit 50a increases the rigidity with respect to the shear force S1, the tensile force S2, and the bending force S4 by the multi-force first direction layer 76A included in the multi-force FRP layer 74, and the torsion force S3. Reduce the rigidity against. Therefore, even when the multi-force detection unit 50a generates the airflow W under the same conditions, the torsional distortion increases and other distortions decrease. Therefore, the wind tunnel testing apparatus 1 can suppress a decrease in measurement accuracy of the rolling moment MX, which is a small force measured by torsional strain.

  The multi-strength FRP layer 74 includes a multi-strength second direction layer 76B in addition to the multi-strength first direction layer 76A. The multi-force second direction layer 76B is laminated in order to adjust the rigidity with respect to the shearing force S1, the tensile force S2, the torsional force S3, and the bending force S4. However, the multi-strength FRP layer 74 may not have the multi-strength second direction layer 76B.

  10A and 10B are schematic diagrams illustrating other examples of the multi-force first direction layer and the multi-force second direction layer. In the multistrength first direction layer 76A according to the second embodiment, a plurality of fibers Fi extend along the multistrength first direction, that is, the extending direction A. Similarly, in the multi-force second direction layer 76B, the plurality of fibers Fi extend in the multi-force second direction, that is, in a direction perpendicular to the extending direction A. However, as shown in FIG. 10A, the multi-strength first direction layer 76A does not have to have a plurality of fibers Fi extending along the multi-strength first direction, and the multi-strength second direction layer 76B The plurality of fibers Fi may not extend along the second direction. A vector V1a in FIG. 10A is a vector obtained by decomposing the length of the fiber Fi into vector components along the multi-force first direction, that is, the extending direction A. A vector V2a in FIG. 10A is a vector obtained by decomposing the length of the fiber Fi into vector components in the second direction of multiple forces, that is, in a direction orthogonal to the extending direction A. In the multi-strength FRP layer 74, the total value of the vectors V1a of all the fibers Fi in the multi-strength FRP layer 74 may be larger than the total value of the vectors V2a of all the fibers Fi in the multi-strength FRP layer 74. When the total value of the vectors V1a of all the fibers Fi in the multi-strength FRP layer 74 is larger than the total value of the vectors V2a, the multi-strength FRP layer 74 has rigidity against the shearing force S1, the tensile force S2, and the bending force S4. The rigidity against the torsional force S3 can be increased.

  As shown in FIG. 10B, the multi-strength FRP layer 74 does not have different layers of the multi-strength first direction layer 76A and the multi-strength second direction layer 76B, and a plurality of one type of FRP layers 76 are stacked. May be. The FRP layer 76 has a plurality of fibers FiAa extending in the same direction, and a plurality of fibers FiBa extending in a direction different from the fibers FiAa. Further, the FRP layer 76 may have only a plurality of fibers FiA extending in the same direction. Even in this case, if the total value of the vectors V1a of all the fibers Fi in the multi-strength FRP layer 74 is larger than the total value of the vectors V2a of all the fibers Fi in the multi-strength FRP layer 74, the multi-strength FRP layer 74 is. Good. The multi-strength FRP layer 74 may be a single layer of the FRP layer 66.

  As described above, the wind tunnel test balance 20 a according to the second embodiment detects forces from a plurality of directions acting on the model 16 provided in the wind tunnel 10. The wind tunnel test balance 20 includes an extending portion 22, a model mounting portion 30, a wind tunnel fixing portion 32, and a multi-force detecting portion 50a. The multi-force detecting unit 50a is provided in the extending part 22, and one end 51a and the other end 52a along the extending direction A are fixed to the extending part 22, and the fiber reinforced plastic. A multi-strength FRP layer 74 which is a layer of Here, the length of the fiber Fi in the multi-strength FRP layer 74 is set to the multi-strength first direction vector component V1a which is the direction along the extending direction A, and the multi-strength second orthogonal to the multi-strength first direction. It decomposes | disassembles into the vector component V2a of a direction. In the multi-strength FRP layer 74, the total value of the vector components V1a of all the fibers Fi in the multi-strength FRP layer 74 is larger than the total value of the vector components V2a.

  In the wind tunnel test balance 20a, the total value of the vectors V1a of all the fibers Fi in the multi-strength FRP layer 74 is larger than the total value of the vectors V2a of all the fibers Fi in the multi-strength FRP layer 74. Accordingly, the wind tunnel test balance 20a has high rigidity with respect to the shearing force S1, the tensile force S2, and the bending force S4, and can reduce the rigidity with respect to the torsional force S3. Therefore, this wind tunnel test balance 20a can suppress a decrease in measurement accuracy of the rolling moment MX, which is a small force.

  The multi-strength FRP layer 74 includes a multi-strength first direction layer 76A in which the fibers Fi extend in the multi-strength first direction and a multi-strength second direction layer 76B in which the fibers Fi extend in the multi-strength second direction. Has been. The total value of the lengths of the fibers Fi of the multi-strength first direction layer 76A is larger than the total value of the lengths of the fibers Fi of the multi-strength second direction layer 76B. The multi-strength FRP layer 74 has a higher rigidity with respect to the shearing force S1, the tensile force S2, and the bending force S4 because the total length of the fibers Fi extending in the multi-strength first direction is longer, and The rigidity with respect to the twisting force S3 can be reduced. Therefore, the multi-strength FRP layer 74 can more suitably suppress a decrease in measurement accuracy of the rolling moment MX that is a small force.

  The multi-force detecting unit 50 a further includes a base material portion 72 that is a metal member, and a multi-force FRP layer 74 is provided on the surface of the base material portion 72. Since this multi-force detection part 50a has the base material part 72, the fall of the measurement precision of the rolling moment MX which is a small force can be suppressed more suitably. However, the multistrength detection unit 50 a may not include the base material portion 72 but may include only the multistrength FRP layer 74.

  The wind tunnel test apparatus 1 according to the second embodiment includes a wind tunnel test balance 20a, a force detection element 17, and a control device 18 (control unit). The force detection element 17 is adhered to the surface of the multi-force detection unit 50a, that is, the surface of the multi-force FRP layer 74, and detects distortion of the multi-force detection unit 50a. The control device 18 calculates the rolling moment MX based on the detection result of the force detection element 17. Since the wind tunnel test apparatus 1 uses the wind tunnel test balance 20, it is possible to suppress a decrease in measurement accuracy of the rolling moment MX, which is a small force.

  The wind tunnel test balance 20 a is a plate-like member provided inside the opening 42, and one side surface is fixed to a predetermined position on the inner surface of the opening 42, and the other side surface is the opening 42. It further has a drag detecting unit 60a fixed at a location facing the direction crossing the extending direction A from the predetermined location on the inner surface. The force detection element 17 is also adhered to the surface of the drag detection unit 60a, and detects the distortion of the drag detection unit 60a. The control device 18 calculates the drag FX acting on the model 16 based on the detection result of the force detection element 17 bonded to the drag detection unit 60a. In the wind tunnel testing apparatus 1, the drag detection unit 60 a detects the drag FX, and the multi-force detection unit 50 a different from the drag detection unit 60 detects the rolling moment MX. Therefore, this wind tunnel testing apparatus 1 can suppress a decrease in measurement accuracy of the force acting on the model 16.

  The wind tunnel test balance 20a may have the drag detection unit 60 according to the first embodiment instead of the drag detection unit 60a. In this case, the wind tunnel test balance 20a can suppress a decrease in measurement accuracy of both the drag force FX and the rolling moment MX, which are small forces.

  As mentioned above, although embodiment of this invention was described, embodiment is not limited by the content of this embodiment. In addition, the above-described constituent elements include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the above-described components can be appropriately combined. Furthermore, various omissions, substitutions, or changes of the components can be made without departing from the spirit of the above-described embodiment.

DESCRIPTION OF SYMBOLS 1 Wind tunnel test apparatus 10 Wind tunnel 12 Strut 14 Sting 16 Model 17 Force detection element 18 Control apparatus 20, 20a Balance for wind tunnel test 22 Extension part 30 Model attachment part 32 Wind tunnel fixing | fixed part 42 Opening part 50, 50a Multi-force detection part 60 Drag Detection unit 62 Base material part 64 Drag FRP layer 66A Drag first direction layer 66B Drag second direction layer 72 Base material part 74 Multi-force FRP layer 76A Multi-force first direction layer 76B Multi-force second direction layer A Extension direction B , C, X, Y, Z direction Fi fiber FX drag FY lateral force FZ lift MX rolling moment MY pitching moment MZ yawing moment

Claims (11)

A wind tunnel test balance for detecting forces from a plurality of directions acting on a model arranged in a wind tunnel,
An extending portion extending in the extending direction along the direction in which the drag acting on the model works,
A model mounting portion provided at one end of the extending portion and fixed to the model;
A wind tunnel fixing portion provided at the other end of the extending portion and fixed to the wind tunnel;
Between the model mounting portion and the wind tunnel fixing portion, an opening provided on a side surface of the extending portion,
A plate-like member provided inside the opening, wherein one side surface is fixed to a predetermined location on the inner surface of the opening, and the other side surface extends from the predetermined location on the inner surface of the opening. A drag detection unit fixed at a location facing the direction crossing the direction and provided with a drag FRP layer, which is a fiber reinforced plastic layer, on the surface;
The length of the fiber in the drag FRP layer is determined based on the vector component in the drag first direction that is the direction from the one side surface toward the other side surface, and the vector component in the drag second direction orthogonal to the drag first direction. The wind tunnel test balance in which the total value of the vector components in the drag second direction of all the fibers in the drag FRP layer is larger than the total value of the vector components in the drag first direction.   The drag FRP layer is formed by laminating a drag first direction layer in which the fibers extending in the drag first direction and a drag second direction layer in which the fibers extending in the drag second direction are arranged. 2. The wind tunnel test balance according to claim 1, wherein a total value of the lengths of the fibers in the drag second direction layer is larger than a total value of the lengths of the fibers in the drag first direction layer.   3. The wind tunnel test balance according to claim 1, wherein the drag detection unit further includes a base material portion that is a metal plate member, and the drag FRP layer is provided on a surface of the base material portion. . A wind tunnel test balance according to any one of claims 1 to 3,
A force detection element that is adhered to the surface of the drag detection unit and detects distortion of the drag detection unit;
A wind tunnel testing device comprising: a control unit that calculates the drag based on a detection result of the force detection element. The wind tunnel test balance further includes a multi-force detection unit provided in the extension part, wherein one end part and the other end part along the extension direction are fixed to the extension part. Have
The force detection element is adhered to the surface of the multi-force detection unit to detect distortion of the multi-force detection unit,
The wind tunnel testing device according to claim 4, wherein the control unit calculates a force other than the drag acting on the model based on a detection result of a force detection element bonded to the multi-force detection unit. The extending portion has one end portion and the other end portion along the extending direction fixed to the extending portion, and has a multi-strength FRP layer which is a fiber reinforced plastic layer on the surface. It further has a multi-force detector,
The length of the fiber in the multi-strength FRP layer is set to a vector component in a multi-strength first direction which is a direction along the extending direction, and a vector component in a multi-strength second direction orthogonal to the multi-strength first direction. The total value of the vector components in the multi-force first direction of all the fibers in the multi-strength FRP layer is larger than the total value of the vector components in the multi-force second direction. The balance for a wind tunnel test according to any one of claims 1 to 3. A wind tunnel test balance for measuring loads from a plurality of directions acting on a model arranged in a wind tunnel,
An extending portion extending in the extending direction along the direction in which the drag acting on the model works,
A model mounting portion provided at one end of the extending portion and fixed to the model;
A wind tunnel fixing portion provided at the other end of the extending portion and fixed to the wind tunnel;
A multi-strength FRP layer, which is provided in the extending portion, has one end portion and the other end portion along the extending direction fixed to the extending portion, and is a fiber reinforced plastic layer. A multi-force detection unit on the surface,
The length of the fiber in the multi-strength FRP layer is set to a vector component in a multi-strength first direction which is a direction along the extending direction, and a vector component in a multi-strength second direction orthogonal to the multi-strength first direction. For the wind tunnel test, the total value of the vector components in the first direction of the multi-force in all the fibers in the multi-strength FRP layer is larger than the total value of the vector components in the second direction of the multi-force. Balance.   The multi-strength FRP layer includes a multi-strength first direction layer in which the fibers extending in the multi-strength first direction and a multi-strength second direction in which the fibers extending in the multi-strength second direction are arranged. The total length of the fibers of the multi-strength first direction layer is larger than the total length of the fibers of the multi-strength second direction layer. The wind tunnel test balance described.   The balance for wind tunnel testing according to claim 7 or 8, wherein the multi-force detecting unit further includes a base material part that is a metal member, and the multi-force FRP layer is provided on a surface of the base material part. . Wind balance test balance according to any one of claims 7 to 9,
A force detection element that is adhered to the surface of the multi-force detection unit and detects distortion of the multi-force detection unit;
A wind tunnel testing apparatus comprising: a control unit that calculates a rolling moment in a rotation direction centering on the extending direction acting on the model based on a detection result of the force detection element. The wind tunnel test balance is:
The extending portion has an opening on a side surface between the model mounting portion and the wind tunnel fixing portion;
A plate-like member provided inside the opening, wherein one side surface is fixed to a predetermined location on the inner surface of the opening, and the other side surface extends from the predetermined location on the inner surface of the opening. Further having a drag detection unit fixed at a location facing the direction crossing the direction,
The force detection element is also bonded to the surface of the drag detection unit to detect distortion of the drag detection unit,
The wind tunnel testing device according to claim 10, wherein the control unit calculates a drag acting on the model based on a detection result of a force detection element bonded to the drag detection unit.

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