JPH11264772A - Measuring method for distribution of physical quantity and structure for executing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for measuring the face distribution of the heat conductivity in the face vertical direction near an object surface. SOLUTION: The colouring material layers 11, 12 of which the colouring states are changed corresponding to the change of temperature and which include the temperature sensitive liquid crystals having the light transmissivity, are mounted on a surface of an object 2A. The white light is emitted from a light source 6, and the reflected light from the colouring material layers 11, 12 are observed by an observing device 7. The main components of the colouring of the colouring material layers 11, 12 are different from each other, and the face distribution of the temperature of the colouring material layers 11, 12 can be independently obtained on the basis of the orthogonality of the colour components. Whereby the face distribution of the heat conductivity in the face vertical direction near a surface of the object 2A can be approximately determined.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the distribution of physical quantities on each of at least two measurement surfaces having a positional relationship so as to overlap each other, and a structure for implementing the method.

[0002]

2. Description of the Related Art In the development of various products, it is very important to know the distribution of physical quantities such as temperature near the surface of an object. For example, when a physical quantity to be known is temperature, it has been conventionally performed to observe a two-dimensional temperature distribution on an object surface by a technique such as thermography.

However, depending on the product to be developed,
In some cases, it is necessary to know the distribution of three-dimensional physical quantities. For example, a case where a gas turbine blade is developed.

In recent years, the combustion temperature of gas turbine blades has been further increased in order to improve efficiency, and accordingly, a cooling medium is allowed to flow inside the blades in order to ensure heat resistance of the blades. The cooling medium is blown from the inside of the wing to the wing surface through cooling holes to form a film of a cooling medium at a lower temperature than the combustion gas on the wing surface. In order to reduce the heat transfer, there is a measure taken.

In designing a turbine blade, it is very important to predict in advance whether the temperature of the blade during operation can be kept below the allowable temperature limit of the blade material. In addition to knowing the two-dimensional temperature distribution of the blade, it is extremely important to know the heat transfer coefficient near the blade surface, that is, the heat transfer coefficient in the direction perpendicular to the surface of the blade. In order to measure the heat transfer coefficient, it is necessary to measure temperatures at different depth positions with respect to the blade surface.

The heat transfer coefficient on the blade surface is often determined by a model experiment simulating the flow of actual combustion gas and cooling medium. In this case, a plurality of temperature sensors such as thermocouples are provided in the direction perpendicular to the blade surface. The heat transfer coefficient in the direction perpendicular to the surface is measured by embedding and measuring the temperature gradient in the direction perpendicular to the surface.

However, when measuring the distribution of the heat transfer coefficient over a wide area of the blade surface by this method, many thermocouples are required. Also, no matter how many thermocouples are prepared, the required heat transfer coefficient is only discretely sampled data, so that it is difficult to measure the distribution of the heat transfer coefficient on the blade surface in detail. In particular, in the case of a wing with a structure in which a cooling medium is blown from the inside of the wing to the wing surface,
Since the flow of combustion gas and cooling medium on the wing surface becomes complicated, and the heat transfer coefficient distribution on the wing surface becomes complicated,
In order to perform effective analysis, it is necessary to acquire detailed and wide-range heat transfer coefficient data, but it is difficult to acquire data with the required accuracy using the above-described method using a thermocouple. .

Therefore, in order to analyze the distribution of the heat transfer coefficient with higher accuracy, the temperature distribution on two surfaces located at different positions in the direction perpendicular to the surface near the blade surface is continuously measured on each surface. It is desired to develop a method for performing the measurement. Such demands are high not only in the development of turbine blades, but also in the development of other products.The physical quantities to be measured are not limited to temperature, and similar needs exist for electrical variables or magnetic variables. high.

[0009]

DISCLOSURE OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and it is intended to continuously distribute the distribution of physical quantities on at least two measurement planes arranged in a mutually overlapping positional relationship on each measurement plane. It is an object of the present invention to provide a method for performing the method, and to provide a structure for implementing the method.

[0010]

In order to achieve the above-mentioned object, the present invention provides a first coloring material layer, whose coloring state changes in response to a change in physical quantity, having a predetermined wavelength from a predetermined direction. Applying a predetermined light from a predetermined direction to a second color forming material layer laminated on the first color forming material layer and having a light transmitting property in which a color forming state changes in response to a change in physical quantity. Irradiating light having a wavelength of
And a step of observing the color development state of the second color development material layer and the step of observing the color development state of the first color development material layer and the second color development material layer, Calculating a physical quantity of the first color-forming material layer and a physical quantity of the second color-forming material layer.

Further, the present invention provides an object, a first color-forming material layer provided directly or indirectly on the surface of the object, the color-forming state of which changes in response to a change in a specific physical quantity;
A second color-forming material layer which is provided directly or indirectly on the first color-forming material layer and has a light-transmitting property with a color change state corresponding to the change of the specific physical quantity;
A structure provided with:

[0012]

Embodiments of the present invention will be described below with reference to the drawings. In the following description of the embodiment, a case where the physical quantity to be measured is temperature will be described.

[First Embodiment] First, a first embodiment will be described with reference to FIG. In the present embodiment, the object 2
1 shows an example in which the present invention is applied for the purpose of approximately measuring a heat transfer coefficient in a method perpendicular to a surface (hereinafter, also referred to as a “perpendicular direction”) with respect to a surface near the surface. That is, in the following description of the present embodiment,
As shown in FIG. 1, an extremely thin measurement laminate 10A is provided on the surface of an object 2A to form a measurement structure (structure) 1A. The measurement structure 1A is placed in an environment in which appropriate heat flow occurs. In this state, a method of approximately and accurately obtaining the heat transfer coefficient in the vicinity of the surface of the object 2A by obtaining the heat transfer coefficient in the stacking direction of the measurement stack 10A in this state will be described.

As shown in FIG. 1, the measurement laminate 10A
Are a first coloring material layer 11 and a second coloring material layer 12 whose coloring state changes with a change in temperature;
And a transparent material layer 15 formed of a light-transmitting material provided between the second color forming material layers 11 and 12. In FIG. 1, reference numeral 5 denotes a fluid such as air and water around the measurement structure 1A.

The transparent material layer 15 is formed of a substantially colorless and transparent material such as vinyl chloride, polyethylene, acryl, and glass.

The first color forming material layer 11 and the second color forming material layer 12 are layers containing a temperature-sensitive liquid crystal whose color changing state changes with temperature. These color-forming material layers are formed, for example, by microencapsulating a temperature-sensitive liquid crystal, applying a binder-added material thereto, and curing the liquid crystal. As the temperature-sensitive liquid crystal, for example, a cholesteric liquid crystal or a chiral nematic liquid crystal is used. These liquid crystals have a property that, when light enters, only light in a specific wavelength range is reflected by an inner layer due to the peculiarity of the structure, and light of other wavelengths is transmitted. . Also,
These liquid crystals have the property that the internal structure changes due to a change in the environment in which they are placed, for example, the strength of a magnetic field or an electric field, or a change in a physical quantity such as temperature, so that the light reflection characteristics, that is, the coloring characteristics change.

In this embodiment, as will be described later, not only the color development of the upper second color forming material layer 12 is observed, but also the color formation of the lower first color forming material layer 11 is changed to the upper second color forming material layer 12. Since the observation is made through the layer 12, the temperature-sensitive liquid crystal contained in each of the first color-forming material layer 11 and the second color-forming material layer 12 indicates that the color development of the underlying first color-forming material layer 11 is the second color-forming material. In order not to be hindered by the coloring of the coloring material layer 12, those having different coloring characteristics in the expected measurement temperature range are selected.

Here, the expected measurement temperature range is determined by the respective surfaces 11 of the first and second color forming material layers 11 and 12.
a and 12a, if the temperature is in the range of temperature a to temperature b, the first and second color forming material layers 1
FIGS. 2 and 3 show the coloring characteristics of the temperature-sensitive liquid crystal used for Nos. 1 and 12, respectively. In the present embodiment,
"Coloring characteristics" means that when a temperature-sensitive liquid crystal is irradiated with white light, each of the colors that it develops has three color components, that is, R,
It means the relationship between the intensity of each component and temperature when decomposed into (Red) component, G (Green) component, and B (Blue) component.

The temperature-sensitive liquid crystal shown in FIG. 2, that is, the temperature-sensitive liquid crystal used as the first color-forming material layer 11, has a color-forming characteristic of the R component of the three color components in the temperature range from temperature a to temperature b. The intensity is the strongest, and the intensity of the G component and the B component is much lower than the intensity of the R component. Also,
As for the rate of change of the intensity with respect to the temperature change, the rate of change of the R component is much larger than the rates of change of the G component and the B component.

On the other hand, the temperature-sensitive liquid crystal shown in FIG.
The temperature-sensitive liquid crystal used as the color-forming material layer 12 has the highest color intensity of the G component among the three color components in the temperature range from the temperature a to the temperature b (hereinafter, the intensity of the three color components is the highest). The strongest component is also referred to as the “primary color component”),
The intensity of the R component and the B component is much lower than the intensity of the G component. That is, R and B pass through the second color forming material layer 12. As for the rate of change of the intensity with respect to the temperature change, the rate of change of the G component is much larger than the rate of change of the R component and the B component.

The color-forming properties of each color-forming material layer are not limited to those described above, but may be different as long as the main color-forming components are different from each other. Color development characteristics of temperature-sensitive liquid crystal,
That is, the light reflection characteristics can be adjusted by appropriately mixing a plurality of materials constituting the temperature-sensitive liquid crystal.

Measurement structure 1 having the above configuration
A typically includes a first coloring material layer 1 on the surface of the object 2.
1. The transparent material layer 15 and the second color forming material layer 12 are sequentially
It is obtained by coating. When reflection on the surface of the object 2 becomes a problem, the first color forming material layer 11 and the object 2
A non-reflective layer (black layer) may be additionally provided on the surface of A.

Next, the measuring laminate 10 having the above-described structure
A method for measuring the heat transfer coefficient in the vicinity of the surface of the object 2A using A will be described.

First, the measurement laminate 10 is placed on the surface of the object 2A.
A measurement structure 1A provided with A is placed under a predetermined measurement environment. Next, light having a predetermined wavelength, preferably white light, is irradiated from the light source 6 toward the surface of the measurement structure 1A, and the surface 11a of the first color-forming material layer 11 and the second color-forming material layer 12 are irradiated. The reflected light from the surface 12a is observed by an appropriate observation device 7, for example, a CCD camera.

Next, each color component is extracted from the reflected light from the coloring material layers 11 and 12 observed by the observation device 7.

As described above, the temperature-sensitive liquid crystal of the first color-forming material layer 11 and the second color-forming material layer 12 have different main color-forming components. Further, the change in the coloring state of the temperature-sensitive liquid crystal of the second coloring material layer 12 can be analyzed without being affected by the other coloring change.

Therefore, the intensity distribution of each color component is analyzed, and based on the known relationship between the temperature and the intensity of the color component, the respective surfaces 11a and 11a of the first color material layer 11 and the second color material layer 12 are determined. The temperature of 12a can be determined independently. That is, the temperatures of two measurement surfaces (surfaces 11a and 12a) having a positional relationship overlapping each other can be obtained independently.

Now, when the temperature of the fluid 5 around the object is Tf and the temperature of the object 2A is Tm and Tf is higher than Tm, the heat flow of the heat flux q that differs depending on the flow state of the fluid 5 is 5 to the object 2A. Assuming that the temperature at the surface 11a of the first color forming material layer 11 is T1 and the temperature at the surface 11a of the first color forming material layer 11 is T0, the heat flux q is obtained as follows.

[0029]

(Equation 1) Here, λ0 and λ1 are the thermal conductivity of the second color forming material layer 12 and the light transmitting material layer 15, respectively, and L0 and L1 are the thicknesses of the second color forming material layer 12 and the transparent material layer 15, respectively. is there.

The local heat transfer coefficient α corresponding to the flow state of the fluid 5 is obtained as follows.

[0031]

(Equation 2) According to the present embodiment, the surface 11 of the first coloring material layer 11
a and the surface 12a of the second coloring material layer 12
Can be continuously observed over a wide range of the surface of the object 2A. Therefore, the object 2
The local heat transfer coefficient α in the vicinity of the surface of A can also be continuously observed over a wide range of the surface of the object 2A.

That is, according to the present embodiment, the temperatures (first physical quantities) at the two measurement surfaces near the surface of the object 2A
Can be continuously obtained as a surface distribution. This makes it possible to continuously obtain the temperature change in the vertical direction near the surface of the object 2A as a surface distribution by comparing the temperatures at the positions corresponding to each other on each measurement surface. The distribution of the heat transfer coefficient (second physical quantity) in the vertical direction can be continuously observed as a surface distribution over a wide range of the object surface.

In the above embodiment, the light to be irradiated is white light, but the light to be irradiated is not limited to this. That is, if measurement by the above method is possible, light other than white light having a predetermined wavelength (wavelength component) may be irradiated.

[Application Example of First Embodiment] Next, an application example of the first embodiment will be described with reference to FIG. An application example described below is an application of the first embodiment to an analysis of a local heat transfer coefficient near the surface of a turbine blade by a model experiment.

As shown in FIG. 4, a measurement structure (turbine blade model) 1B includes a first coloring material layer 11, a transparent material layer 15, and a second coloring material on a surface of an object 2B simulating a turbine blade. It is configured by sequentially laminating the material layers 12. The cooling holes 7 through which the cooling medium 6 flows are provided in the object 2B, the first
Is formed so as to penetrate the color-forming material layer 11, the transparent material layer 15, and the second color-forming material layer 12.

The turbine blade model 1B shown here is a heat transfer performed when researching a method of blowing a cooling medium from the inside of the turbine blade to the blade surface to reduce the transfer of heat from the combustion gas to the blade member. Used for rate analysis. The blowing of the cooling medium 6 causes a complicated flow state of the main flow 8 and the cooling medium 6 around the cooling holes 7 on the surface of the object 2B, and in particular, it is possible to know the heat transfer coefficient downstream of the cooling holes 7 in detail. It is important in cooling hole design. In this application example, the local heat transfer coefficient downstream of the cooling hole can be continuously observed, and the performance of the cooling hole can be easily evaluated.

It is to be noted that this application example can be used for analyzing a compressor blade constituting a gas turbine plant. Further, the application object is not limited to a model, and can be used for thermal analysis of a wing in an actual device.

[Second Embodiment] Next, a second embodiment will be described with reference to FIG. In the second embodiment,
The second embodiment differs from the first embodiment in that the second color-forming material layer is intermittently removed, and is otherwise substantially the same as the first embodiment. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and duplicate description will be omitted.

As described in the first embodiment, by making the coloring characteristics of a plurality of laminated thermosensitive liquid crystals different from each other, the coloring of the lower thermosensitive liquid crystal becomes the same as that of the upper thermosensitive liquid crystal. Observations can be made without interruption. However, when the observation is performed in a wider temperature range, the color forming characteristics of the lower temperature-sensitive liquid crystal and the color forming characteristics of the upper temperature-sensitive liquid crystal may interfere with each other, which may affect the identification of the temperature.

Therefore, in the present embodiment, as shown in FIG. 5, the second coloring material layer 12 is intermittently and regularly removed to expose a part of the transparent material layer 15 to the outside. I have. The removed portion of the second coloring material layer 12 is the transparent material layer 15
Are filled with the projections 15a. Thus, the surface of the measurement laminate 10B is a flat surface without irregularities.

In the present embodiment, the color-developed state of the temperature-sensitive liquid crystal of the lower first color-forming material layer 11 can be directly observed through the projection 15a of the transparent material layer 15.
By observing the change in color around the protrusion 15a, it is possible to determine the effect of the coloring of the temperature-sensitive liquid crystal of the upper second coloring material layer 12 on the coloring of the temperature-sensitive liquid crystal of the lower first coloring material layer 11. You can know. The influence of the temperature-sensitive liquid crystal of the second color-forming material layer 12 obtained here can be used for correction in temperature identification of the temperature-sensitive liquid crystal of the first color-forming material layer 11 based on observation results of a portion other than the protrusion 15a. it can. In the vicinity of the protrusion 15a, a wide area where the two interfere with each other based on the coloring of the temperature-sensitive liquid crystal of the first coloring material layer 11 and the coloring of the temperature-sensitive liquid crystal of the second coloring material layer 12. Even in the temperature range, the heat transfer coefficient can be directly obtained without correction.

[Third Embodiment] Next, FIG.
An embodiment will be described. In the third embodiment, the first
The third embodiment is different from the first embodiment in that a transparent material layer is omitted, and the other portions are substantially the same as the first embodiment. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and duplicate description will be omitted.

According to the present embodiment, since there is no transparent material layer, two color-forming material layers can be laminated in a thinner state on the surface of the object, and even when the surface of the object 2 has undulation, it is easy. A color-forming material layer. Also,
According to the present embodiment, it is possible to easily additionally laminate a temperature-sensitive liquid crystal on the surface of an existing object, and the present invention can be applied to a wider range of measurement objects.

In the case of the present embodiment, the local heat transfer coefficient α corresponding to the flow state of the fluid 5 can be obtained by the following equation.

[0045]

(Equation 3) Here, λ0 is the thermal conductivity of the second color forming material layer 12, L0
Is the thickness of the second coloring material layer, and T0, T1 and Tf are the temperature of the surface of the second coloring material layer 12, the temperature of the surface of the first coloring material layer 11, and the temperature of the fluid 5, respectively.

[Fourth Embodiment] Next, FIGS.
The fourth embodiment will be described with reference to FIG. The fourth embodiment is different from the first embodiment in that a color-forming material layer and a transparent material layer are additionally provided one by one, and the others are substantially the same as the first embodiment. It is. In the fourth embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and overlapping description will be omitted.

As shown in FIG. 7, a measurement laminate 10D according to the present embodiment is composed of a transparent material layer 15 on the second color-forming material layer 12 of the measurement laminate 10A according to the first embodiment.
And the third coloring material layer 13 are sequentially laminated.

The first, second and third color forming material layers 11,
The temperature-sensitive liquid crystals 12 and 13 are different from each other in the main components of color development. Therefore, since the main components of the color development of the temperature-sensitive liquid crystal of the first and second color-forming material layers 11 and 12 are R and G, respectively, here, the temperature-sensitive liquid crystal of the third color-forming material layer 13 is shown in FIG. As shown in FIG. 7, a colorant whose main component is B is used.

As a result, due to the orthogonality between the color components, the change in the color development state of the temperature-sensitive liquid crystal of the first color-forming material layer 11 is changed by the color development of the temperature-sensitive liquid crystal of the second and third color-forming material layers 12 and 13. The change in the coloring state of the temperature-sensitive liquid crystal of the second color-forming material layer 12 can be observed without being hindered by the coloring of the temperature-sensitive liquid crystal of the third color-forming material layer 13.

In the embodiments described so far,
In each case, it is assumed that the heat flow on the surface of the object is perpendicular to the surface. However, depending on the conditions, there may be a heat flow in the direction along the surface on the object surface. In the present embodiment, it is possible to observe the temperatures of the three layers on the surface of the object.
When there is a heat flow in the direction along the surface between the second color forming material layer 13 and the second color forming material layer 13, the heat flow is applied to the surface between the second color forming material layer 12 and the third color forming material layer 13. It can be observed as a difference between the flow of heat in the vertical direction and the flow of heat in the direction perpendicular to the surface between the first color forming material layer 11 and the second color forming material layer 12.

In the first to fourth embodiments described above, each of the coloring material layers used has a light-transmitting property, but is located at a position closest to the object 2A (2B). Obviously, the color-forming material layer 11 that is not provided, that is, the color-forming material layer farthest from the observation position does not necessarily need to have light transmittance. Therefore, the coloring of the first coloring material layer 11 does not necessarily have to be based on the temperature-sensitive liquid crystal.

[Fifth Embodiment] Next, FIG.
An embodiment will be described. The fifth embodiment is different from the first to fourth embodiments described above in that the heat transmittance of the transparent object 2C having optical transparency is measured. Note that the object 2C and the first color forming material layer 11 and the second color forming material layer 1 disposed on both side surfaces of the object 2C.
2 has substantially the same configuration as the measurement structure 10 in the first embodiment. In the fifth embodiment, the same portions as those in the first embodiment are denoted by the same reference numerals, and overlapping description will be omitted.

The structure 1F according to the present embodiment includes a fluid 5A
And the flow of the fluid 5B. Then, based on the temperatures of the first color forming material layer 11 and the second color forming material layer 12 identified based on the color development of the temperature-sensitive liquid crystal of the first color forming material layer 11 and the second color forming material layer 12, The heat transmittance of the transparent object 2C between the fluid 5A and the fluid 5B can be measured.

In the above description of the first to fifth embodiments, temperature is used as an example of a physical quantity and temperature-sensitive liquid crystal is used as an example of a coloring material. However, the present invention is not limited to this. is not. That is, the physical quantity to be measured by the present invention may be, for example, a physical quantity such as pressure, stress, strain, an electric field, a magnetic field, or the like, or may be a chemical substance other than liquid crystal as a coloring material.

For example, when a voltage is taken as a physical quantity, the current distribution on the object surface can be continuously observed in a wide range based on the observation of the voltage distribution.

Further, for example, when strain is taken as a physical quantity, the stress distribution on the object surface can be continuously observed in a wide range based on the strain distribution. In this case, for example, a color-forming material layer may be formed by dispersing capsules that are crushed and colored in response to stress in a binder and apply and cure the object surface.

[0057]

As described above, according to the present invention,
The distribution of physical quantities on at least two measurement planes arranged in a positional relationship overlapping each other can be continuously measured on each measurement plane.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view for explaining a measurement method and a structure according to a first embodiment of the present invention.

FIG. 2 is a diagram showing color development characteristics of a temperature-sensitive liquid crystal used in the first embodiment.

FIG. 3 is a diagram showing color development characteristics of a temperature-sensitive liquid crystal used in the first embodiment.

4A and 4B are views showing an application example of the first embodiment, and FIG. 4A is a partially cutaway perspective view of a turbine blade model;
(B) is a figure showing the BB section in Drawing 4 (a).

FIG. 5 is a sectional view for explaining a second embodiment of the structure according to the present invention.

FIG. 6 is a sectional view for explaining a third embodiment of the structure according to the present invention.

FIG. 7 is a sectional view for explaining a fourth embodiment of the structure according to the present invention.

FIG. 8 is a diagram showing color development characteristics of a temperature-sensitive liquid crystal used in a fourth embodiment.

FIG. 9 is a sectional view for explaining a fifth embodiment of the structure according to the present invention.

[Explanation of symbols]

 1A, 1B, 1C, 1D, 1E, 1F Structure 2A Object 2B Turbine blade model (as an example of object) 11, 12, 13 Coloring material layer 15 Transparent material layer

Claims (10)

[Claims] A step of irradiating, from a predetermined direction, light having a predetermined wavelength to a first color forming material layer whose color forming state changes in response to a change in physical quantity; Irradiating a light having a predetermined wavelength from a predetermined direction to a second color forming material layer having a light transmitting property in which a color forming state changes in response to a change in a physical quantity; And a step of observing a color development state of the second color development material layer, and a step of observing the color development state of the first color development material layer and the second color development material layer, Calculating a physical quantity of the first color-forming material layer and a physical quantity of the second color-forming material layer. 2. The method according to claim 1, wherein each of the coloring material layers has different coloring characteristics with respect to the change of the physical quantity. 3. The method according to claim 1, wherein the physical quantity is a temperature. 4. A method for determining a heat transfer coefficient in a direction perpendicular to a surface near a surface of an object, the method comprising: directly or indirectly providing a first color-forming material layer comprising a temperature-sensitive liquid crystal on the surface of the object. Providing a transparent material layer having a light transmitting property on the first color forming material layer; providing a second color forming material layer on the light transmitting material layer; Observing the coloring state of the first and second coloring material layers; and the first and second coloring material based on the relationship between the coloring state of the first and second coloring material layers and the temperature. Calculating a temperature in the layer; a thermal conductivity in the direction perpendicular to the plane based on a thermal conductivity of the color forming material layer and the light transmitting material layer and a temperature distribution of the first and second color forming material layers. The process of seeking
A method comprising: 5. An object, a first color-forming material layer provided directly or indirectly on the surface of the object, the color-forming state of which changes in response to a change in a specific physical quantity; and the first color-forming. A second color-forming material layer provided directly or indirectly on the material layer, the color-forming state of which changes in response to the change of the specific physical quantity, and has light transmittance;
A structure comprising: 6. The structure according to claim 5, wherein a transparent material layer having a light transmitting property is provided between said first coloring material layer and said second coloring material layer. Stuff. 7. The structure according to claim 5, wherein the first and second coloring material layers have different coloring characteristics with respect to the change of the physical quantity. 8. The structure according to claim 5, wherein said physical quantity is a temperature. 9. The structure according to claim 8, wherein said first and second color-forming material layers are layers containing a temperature-sensitive liquid crystal whose coloring state changes in response to a temperature change. 10. The structure according to claim 8, wherein the object is a gas turbine blade or a compressor blade constituting a gas turbine system, or an experimental model of the gas turbine blade or the compressor blade.