CN103411643B - Fibre Optical Sensor and measuring method for air compressor fluid measuring multiple parameters - Google Patents

Abstract

The present invention proposes a kind of light intensity formula and raster pattern hybrid fiber flow sensor and measuring method, and Bragg grating formula optical fiber is symmetrically distributed in cyclic spring foil gauge surface, calculates static pressure by the side-play amount of fiber optic hub wavelength；Light intensity fiber perpendicular is irradiated to elastic strain sheet center, and is received optical fiber reception reflection light by two groups, is calculated the offset distance of elastic strain sheet by two groups of light intensity ratios receiving optical fiber, thus calculates stagnation pressure；Thermometric grating fibers sticks in Pitot tube inwall, calculates compressor stagnation temperature by the side-play amount of thermometric grating fiber optic hub wavelength；Another thermometric grating optical fiber horizontal is fixed on the temperature measuring working environment inside cylindrical metallic shell, and stagnation pressure and static pressure are carried out temperature-compensating.Features such as it is little that the present invention not only has Fibre Optical Sensor volume, simple in construction, and antijamming capability is strong, an and sensor measurement fluid stagnation pressure can be realized, static pressure, stagnation temperature, multiple parameters such as flow.

Description

Fibre Optical Sensor and measuring method for air compressor fluid measuring multiple parameters

Technical field

The present invention relates to the fiber optic sensor technology field that engine gas flow rate is measured, be specially one for compressor The light intensity formula of fluid measuring multiple parameters and raster pattern hybrid fiber sensor and measuring method.

Background technology

Optical fiber sensing technology arises from the seventies in last century, and the nineties enters China.The most domestic have many research aircrafts Structure starts with technique and carries out research and development and the making of product.For needing under the particular surroundings such as Aeronautics and Astronautics to utilize The gas flow sensor arrived, is characterized in existing higher dynamic response and the linearity of preferable static measurement, also There are anti-electromagnetic interference and preferable high-temperature stability.

Compressor is one of core component of aero-engine, and the properly functioning of whole engine is had by its duty Important function.And needed for the compressor of high pressure ratio is the development trend of military aero-engine, be again aero-engine In the parts that easily break down, and generally, pressure ratio is the highest, is more susceptible to surge.If compressor is not Can normally be operated so that generation surge, it would be possible to cause leaf destruction, structural failure, combustion chamber overtemperature and engine The catastrophe failure such as flame-out, it is necessary for therefore monitoring it in real time.And in the monitoring of numerous parameters, flow Measuring is again emphasis therein and difficult point.Optic flow sensor is compared to conventional pressure sensor, and it is to strain, temperature Degree, displacement etc. have higher sensitivity, have again little, lightweight, anticorrosive, the electromagnetism interference of volume etc. excellent simultaneously Point.Therefore compressor gas flow is measured by application Fibre Optical Sensor, the most accurately surveys for compressor gas flow Amount provides a kind of settling mode.Additionally, solving issues of temperature compensation while high-acruracy survey is also fiber optic flow Key issue during sensor is practical.

Cheng Jia of Zhejiang Province Measure Science & Technology Research Institute et al. has invented a kind of multi-section distributed fiber grating heat type flow quantity and has passed Sensor (Chinese patent 102564504, on 07 11st, 2012), has 3 grating fibers in this sensor tube wall Sensor, is arranged symmetrically with into " river " font, and 3 optical fiber are positioned on same sagittal plane.This sensor leads to Cross grating light and measure the temperature of fluid different piece, draw the flow of fluid.The most this flow sensor response speed Spend the slowest；The place that measured gas component changes greatly, because cp value and thermal conductivity change, measured value has bigger Change and produce error；Due to mechanical fiber optic intensity difference, for flow velocity blower outlet faster, due to compressor mouth Footpath is relatively big, and optical fiber is it may happen that rupture.Therefore study further that a kind of response for blower outlet is sensitive, survey Measure accurate flow of light quantity sensor, can be as compressor sensing system a pith.

Summary of the invention

Solve the technical problem that

For solving the problem that prior art exists, the present invention proposes a kind of light intensity for air compressor fluid measuring multiple parameters Formula and raster pattern hybrid fiber sensor and measuring method.

Technical scheme

A kind of light intensity formula for air compressor fluid measuring multiple parameters and raster pattern hybrid fiber sensor, including Pitot tube 11；It is characterized in that: include annular static pressure elastic strain sheet 1, circular stagnation pressure elastic strain sheet 2, cylindrical metallic encapsulation Shell 3, double-round axis light strong reflection formula fibre-optical probe 4, thermometric grating fibers 8 and thermometric grating fibers 10；Tubular Metal-packaged shell 3 is connected to the measurement interface of Pitot tube 11, at cylindrical metallic package casing 3 with Pitot tube 11 even Connect part and the center annular static pressure elastic strain sheet 1 with through hole is set, at the other end of cylindrical metallic package casing 3 Being provided with through hole, double-round axis light strong reflection formula fibre-optical probe 4 is placed in the vacuum chamber of cylindrical metallic package casing 3, and Drawn by through hole and launch and receive optical fiber；At annular static pressure elastic strain sheet 1 and double-round axis light strong reflection formula optical fiber Circular stagnation pressure elastic strain sheet 2 it is provided with between probe 4；Thermometric grating fibers 10 is arranged on Pitot tube 11 pitot hole B Inwall on；On the inwall of the vacuum chamber that thermometric grating fibers 8 is arranged on cylindrical metallic package casing 3；Described annular Static pressure elastic strain sheet 1 is to paste some tonometric grating fibers, some pressure on annular static pressure elastic strain sheet The grating fibers 9 measured circumferentially is uniformly distributed；Transmitting on described double-round axis light strong reflection formula fibre-optical probe 4 and The arrangement receiving optical fiber is: the center of optical fiber is a launching fiber, and the periphery of launching fiber is provided with six root receiving fibers Forming first group and receive optical fiber 6, first group of periphery receiving optical fiber 6 is provided with 12 root receiving fibers and forms second group and connect Receive optical fiber 7；Described annular static pressure elastic strain sheet 1, circular stagnation pressure elastic strain sheet 2, thermometric grating fibers 8 and survey Temperature grating fibers 10 is provided with signal output connecting line.

Described measuring pressure grating fibers 9 is Bragg grating optical fiber.

Described double-round axis light strong reflection formula fibre-optical probe 4 with the distance of circular stagnation pressure elastic strain sheet 2 is 0.25mm～2.5mm.

The outer application high-temperaure coating of described cylindrical metallic package casing 3.

Described annular static pressure elastic strain sheet 1 and circular stagnation pressure elastic strain sheet 2 select comprehensive silicon material.

A kind of method of testing utilizing described sensor to carry out compressor gas flow, it is characterised in that step is as follows:

Step 1: the light received by receiving optical fiber carries out opto-electronic conversion and gathers, obtains two groups of light intensity receiving light Ratio M (z):

$M\left(z\right)=\exp =\left\{\frac{-3\·d^2}{{a_0}^2{[1+\mathrm{\ζ}{\left(\frac{2z}{a_0}\right)}^{3/2}\tan {\mathrm{\θ}}_0]}^2}\right\}+\exp \left\{\frac{-2\·d^2}{{\mathrm{\σ}}^2{a_0}^2{[1+\mathrm{\ζ}{\left(\frac{2z}{a_0}\right)}^{3/2}\tan {\mathrm{\θ}}_0]}^2}\right\}$

And obtain the relation between circular stagnation pressure foil gauge displacement z and light intensity ratio M (z), wherein incident optical with connect The distance between axles receiving optical fiber is d, the radius of fibre bundle optical fiber is a₀, the maximum incident angle of optical fiber be θ₀, σ for characterize light The fine relevant parameter of index distribution, ζ are the modulation parameter relevant with light source category and light source and optical fiber coupling condition；

Step 2: according to circular stagnation pressure foil gauge displacement z, calculate stagnation pressure p^*=z*(AE), wherein A is pressure effect Cross-sectional area, E are the elastic modelling quantity of selected materials；

Step 3: use relationship delta λ of strain and wavelength shift_B=(1-P_e)ε·λ_BIt is calculated annular static pressure foil gauge Deformation quantity ε, wherein p_eIt is the strain optical coefficient of optical fiber, λ_BRepresent the centre wavelength of light in grating；

Step 4: dependent variable ε according to cyclic spring foil gauge is proportional with Δ p: ε ∝ Δ p, calculates annular elastomeric Pressure differential deltap p of property foil gauge both sides, obtains static pressure p=Δ p+p*；

Step 5: by the change of the operating ambient temperature that grating fiber optic 8 records, compensates owing to temperature change causes The measurement drift of elastic strain sheet, wherein α be the thermal coefficient of expansion of optical fiber, ξ be that the thermo-optical coeffecient of optical fiber, Δ λ are The change of wavelength, Δ T be the change of temperature, λ be the centre wavelength of light in grating；Temperature change becomes in grating wavelength The relation changed: Δ λ=(α+ξ) λ Δ T；

Step 6: obtained the stagnation temperature T* of compressor by temperature-measuring optical fiber 10；

Step 7: according to p^*, p, T*, calculate gas flow, its computational methods are as follows:

$G=K\frac{p*}{\sqrt{T*}}A{\left(\frac{\mathrm{\κ}+1}{2}\right)}^{\frac{1}{\mathrm{\κ}-1}}\sqrt{\frac{\mathrm{\κ}+1}{\mathrm{\κ}-1}}\sqrt{{\left(\frac{p}{p*}\right)}^{\frac{2}{\mathrm{\κ}}}-{\left(\frac{p}{p*}\right)}^{\frac{\mathrm{\κ}+1}{\mathrm{\κ}}}}$

In formula, K is constant, and κ is gas constant, and A is the pneumatic area measuring cross section, and p* is stagnation pressure, and p is static pressure, T* is stagnation temperature.

Beneficial effect

The present invention uses the optical fiber measurement as engine flow and the critical component of temperature-compensating, it is proposed that a kind of light intensity Formula and raster pattern hybrid fiber flow sensor and measuring method.This sensor construction is simple, volume is little, precision is high, Use thermometric grating optical fiber measurement compressor delivery temperature, use measuring pressure grating fibers to measure static pressure, use light intensity anti- Penetrate the distance of formula optical fiber measurement elastic strain sheet to reach the purpose of total pressure measurement, thus accurately measure compressor air inlet machine mouth The exact value of flow.Use grating fiber optic to measure temperature residing for sensor in order to carry out the compensation of temperature drift simultaneously Improve sensor accuracy further.So, this sensor of short summary has the advantage that 1, the present invention uses elasticity Foil gauge is as sensing element, and application grating fibers and light intensity optical fiber are as measuring cell, and this mode can effectively carry The precision that high flow capacity is measured；2, the present invention uses grating fibers directly to measure sensor local environment temperature, utilizes temperature Compensate and realize the accurate measurement to pressure；3, inventive sensor simple in construction, volume energy little, lightweight, anti-interference Power is strong and precision reliability is high.

Accompanying drawing explanation

The structural representation of Fig. 1: the present invention；

Pressure grating fibers distribution map is measured in Fig. 2: Fig. 1

The partial enlarged drawing of double-round axis light strong reflection formula optical fiber in Fig. 3: Fig. 1；

Wherein: 1, static pressure elastic strain sheet;2, stagnation pressure elastic strain sheet;3, cylindrical metallic shell;4, optical fiber is visited Head;5, launching fiber;6, optical fiber is received;17, optical fiber 2 is received;8, thermometric grating fibers 1;9 pressure measurement gratings Optical fiber;10, thermometric grating fibers 2;11, Pitot tube;A, baroport；B, pitot hole

Detailed description of the invention

Below in conjunction with specific embodiment the present invention described:

Referring to the drawings 1, a kind of light intensity formula for air compressor fluid measuring multiple parameters in the present embodiment is mixed with raster pattern Close Fibre Optical Sensor and include Pitot tube 11；It is characterized in that: include annular static pressure elastic strain sheet 1, circular stagnation pressure bullet Property foil gauge 2, cylindrical metallic package casing 3, double-round axis light strong reflection formula fibre-optical probe 4, thermometric grating fibers 8 With thermometric grating fibers 10；Cylindrical metallic package casing 3 is connected to the measurement interface of Pitot tube 11, at cylindrical metallic Package casing 3 arranges the center annular static pressure elastic strain sheet 1 with through hole with Pitot tube 11 in place of being connected, at tubular The other end of metal-packaged shell 3 is provided with through hole, and double-round axis light strong reflection formula fibre-optical probe 4 is placed in cylindrical metallic envelope In the vacuum chamber of casing 3, and draw transmitting by through hole and receive optical fiber；Annular static pressure elastic strain sheet 1 with Circular stagnation pressure elastic strain sheet 2 it is provided with between double-round axis light strong reflection formula fibre-optical probe 4；Thermometric grating fibers 10 sets Put on the inwall of Pitot tube 11 pitot hole B；Thermometric grating fibers 8 is arranged on the true of cylindrical metallic package casing 3 On the inwall of cavity；Described annular static pressure elastic strain sheet 1 is to paste some pressure on annular static pressure elastic strain sheet to survey The grating fibers of amount, 8 groups of tonometric grating fibers 9 are circumferentially uniformly distributed；Described double-round axis light strong reflection Transmitting on formula fibre-optical probe 4 and receive the arrangement of optical fiber and be: the center of optical fiber is a launching fiber, launching fiber Periphery be provided with six root receiving fibers formed first group receive optical fiber 6, first group receive optical fiber 6 periphery be provided with 12 Root receiving fiber forms second group and receives optical fiber 7；Described annular static pressure elastic strain sheet 1, circular stagnation pressure elastic strain sheet 2, thermometric grating fibers 8 and thermometric grating fibers 10 are provided with signal output connecting line.

Measuring pressure grating fibers is symmetrically and evenly distributed in annular static pressure foil gauge surface.

The axis direction of light intensity fibre-optical probe should overlap with the axis direction of elastic strain sheet.

Light intensity fibre-optical probe is maintained at 0.25mm-2.5mm with the distance of elastic strain sheet.

The material of selected elastic strain sheet is special composite material, this material have high temperature resistant, the higher-strength limit and The feature of the higher proportion limit.

Selected cylindrical metallic package casing, the metal that inner side selection thermal conductivity is good, outside uses the metal of poor thermal conductivity also Add high-temperaure coating.

Pass through between outward flange and the edge of described Metal Packaging housing tip of described annular static pressure elastic strain sheet Securing member is connected.

The inward flange of described annular static pressure elastic strain sheet is closely coupled with the stagnation pressure tube of described Pitot tube, and scribbles High-intensity sealing glue.

The edge of described stagnation pressure elastic strain sheet draw-in groove internal with described Metal Packaging is connected by securing member, and Scribbling high-intensity sealing glue, described stagnation pressure elastic strain sheet constitutes an airtight vacuum chamber with the internal cavities of housing.

The material of static pressure elastic strain sheet 1 and stagnation pressure elastic strain sheet 2 is special composite material, and this material has resistance to High temperature, the higher-strength limit and the feature of the higher proportion limit, can be selected for comprehensive silicon material in the present invention, this is because The temperature of aero-engine compressor up to about 500K and need measure pressure be 0-5Mpa.

Cylindrical metallic shell 3 is made up of materials at two layers, for ensureing the strength and stiffness requirement of encapsulating housing, materials at two layers It is alloy material.Wherein internal layer is the alloy material that thermal conductivity is good, to ensure that thermometric grating fibers can be surveyed accurately The operating ambient temperature of quantity sensor, outer layer uses the metal of poor thermal conductivity and adds high-temperaure coating.

Pressure measurement grating fibers 9 is pasted onto static pressure foil gauge surface by particular adhesive, because aero-engine compressor Temperature is up to 500k, so this adhesive high-temperature stability to be had.

The incident light source of the light intensity reflection type optical fiber in the present embodiment should select according to optical-electrical converter, selects in the present invention Ruddiness is as light source.And incident light is shining into sealing vacuum chamber can get rid of external light source and the interference impact on sensor.

When the light intensity formula of the present invention works with raster pattern hybrid fiber flow sensor, when extraneous static pressure acts on static pressure During elastic strain sheet 1, static pressure elastic strain sheet 1 deforms upon, and pastes pressure measurement grating fibers 9 length with 1 surface Change simultaneously, and then cause the centre wavelength of optical grating reflection to offset；Simultaneously stagnation pressure act on total compression elasticity should Becoming sheet 2, stagnation pressure foil gauge 2 deforms upon, between incident optical 5 and stagnation pressure elastic strain sheet 2 lower surface center There is minor variations in distance, so that the light intensity that inner ring receives optical fiber 6 and outer ring reception optical fiber 7 reception changes； Meanwhile, the thermometric grating fibers 8 being in same temperature field can detect that change that temperature occurs causes optical grating reflection Centre wavelength offset.Therefore can be according to the pass between optical grating reflection centre wavelength and the static pressure elastic strain sheet of 9 System, and combine the relation of pressure and the strain of elastic strain sheet, calculate the size of measured static pressure；According to light intensity change with Relation between distance change, and combine the relation between pressure and the strain of elastic strain sheet, calculate and surveyed total pressure pressure Size；The size of residing temperature is calculated by the side-play amount of the optical grating reflection centre wavelength of thermometric grating 8, thus Realize accurately measurement and the temperature-compensating of compressor static pressure and stagnation pressure；By the optical grating reflection centre wavelength of thermometric grating 10 Side-play amount calculate compressor stagnation temperature.According to the relation of static pressure, stagnation pressure, stagnation temperature and gas flow, can calculate The size of surveyed gas flow.Concrete calculating process is as follows:

Stagnation pressure elastic strain sheet as follows by stress-strain formula:

Z=p*/(AE) (1)

In formula, z is the dependent variable produced, and A is the cross-sectional area of pressure effect, and E is the elastic modelling quantity of selected materials, p* For the pressure applied.

Referring to the drawings 3, according to the fibre bundle arrangement mode of double-round coaxial optical fiber probe, two groups of reception optical fiber are received Light intensity carry out ratio proccessing, the computing formula of the output characteristics modulation function of this sensor can be obtained, i.e.

$M\left(z\right)=\frac{I_{r2}}{I_{r1}}=\frac{{6I}_2+{6I}_3}{{6I}_1}---\left(2\right)$

In formula:

M (z) is the ratio of two groups of reception fibre bundle light intensity；

I_r1Represent that first group receives light intensity/cd that fibre bundle receives；

I_r2Represent that second group receives light intensity/cd that fibre bundle receives.

The change z that strain displacement occurs can be calculated by ratio M (z) of two groups of light intensity receiving collecting fiber,

Specific formula for calculation is as follows:

$M\left(z\right)=\exp =\left\{\frac{-3\·d^2}{{a_0}^2{[1+\mathrm{\ζ}{\left(\frac{2z}{a_0}\right)}^{3/2}\tan {\mathrm{\θ}}_0]}^2}\right\}+\exp \left\{\frac{-2\·d^2}{{\mathrm{\σ}}^2{a_0}^2{[1+\mathrm{\ζ}{\left(\frac{2z}{a_0}\right)}^{3/2}\tan {\mathrm{\θ}}_0]}^2}\right\}---\left(3\right)$

By formula (3), when optical fiber structure parameter incident optical and reception distance between axles d of optical fiber, fibre bundle optical fiber Radius a₀, the maximum incident angle θ of optical fiber₀One timing, optical fiber output characteristics is only and fiber end face is between strain diaphragm Distance z relevant, and with the intensity of light source, the reflectivity of reflector, the intrinsic loss of optical fiber and brought by bending The factors such as added losses are unrelated.Therefore its ratio is obtained after light intensity being carried out opto-electronic conversion, by formula (3) convolution (1) Calculate the stagnation pressure of compressor.

Static pressure elastic strain sheet dependent variable and the relation of static pressure:

During normal operation of sensor, there is pressure differential deltap p in cyclic spring foil gauge both sides:

Δ p=p-p* (4)

In formula, p is static pressure, and p* is stagnation pressure.

Being experimentally confirmed, dependent variable ε of cyclic spring foil gauge is proportional with Δ p:

ε ∝ Δ p (5)

Grating wavelength side-play amount and the relation of strain:

Δλ_B=(1-P_e)ε·λ_B(6)

P in formula_eIt it is the strain optical coefficient of optical fiber.

Therefore, Δ p and Δ λ_BLinear, by the demodulation to optical signal, it can be deduced that Δ λ_B, and then can obtain Go out Δ p.Stagnation pressure p* is obtained, such that it is able to draw the static pressure p of fluid by formula (1), formula (3).

The stagnation temperature T* of compressor can be obtained by temperature-measuring optical fiber 10.The working environment that can be recorded by grating fiber optic 8 The change of temperature, the measurement drift of the elastic strain sheet that compensation causes due to temperature change.Temperature change is in grating wavelength The relation of change:

Δ λ=(α+ξ) λ Δ T (7)

In formula, α is the thermal coefficient of expansion of optical fiber, and ξ is the thermo-optical coeffecient of optical fiber, and Δ λ is the change of wavelength, and Δ T is The change of temperature.

According to the relation of static pressure, stagnation pressure, stagnation temperature and gas flow, the size of surveyed gas flow can be calculated:

$G=K\frac{p*}{\sqrt{T*}}A{\left(\frac{\mathrm{\κ}+1}{2}\right)}^{\frac{1}{\mathrm{\κ}-1}}\sqrt{\frac{\mathrm{\κ}+1}{\mathrm{\κ}-1}}\sqrt{{\left(\frac{p}{p*}\right)}^{\frac{2}{\mathrm{\κ}}}-{\left(\frac{p}{p*}\right)}^{\frac{\mathrm{\κ}+1}{\mathrm{\κ}}}}---\left(8\right)$

In formula, K is constant, and κ is gas constant, and A is the pneumatic area measuring cross section, and p* is stagnation pressure, and p is static pressure, T* is stagnation temperature.

By being connected on Wavelength demodulation instrument by the output of grating fibers, the change of wavelength can be recorded, thus logical Cross the variable quantity being calculated temperature, complete the hybrid fiber flow sensor of whole light intensity formula optical fiber and grating fiber optic Design.

Claims (6)

1. for light intensity formula and the raster pattern hybrid fiber sensor of air compressor fluid measuring multiple parameters, including Pitot tube (11)；It is characterized in that: include annular static pressure elastic strain sheet (1), circular stagnation pressure elastic strain sheet (2), Cylindrical metallic package casing (3), double-round axis light strong reflection formula fibre-optical probe (4), the first thermometric grating fibers (8) and the second thermometric grating fibers (10)；Cylindrical metallic package casing (3) is connected to Pitot tube (11) Measure interface, in place of cylindrical metallic package casing (3) is connected with Pitot tube (11), center is set with through hole Annular static pressure elastic strain sheet (1), the other end at cylindrical metallic package casing (3) is provided with through hole, double-round Axis light strong reflection formula fibre-optical probe (4) is placed in the vacuum chamber of cylindrical metallic package casing (3), and passes through Through hole is drawn and is launched and receive optical fiber；At annular static pressure elastic strain sheet (1) and double-round axis light strong reflection formula light Circular stagnation pressure elastic strain sheet (2) it is provided with between fine probe (4)；Second thermometric grating fibers (10) is arranged on On the inwall of Pitot tube (11) pitot hole B；First thermometric grating fibers (8) is arranged on outside cylindrical metallic encapsulation On the inwall of the vacuum chamber of shell (3)；Described annular static pressure elastic strain sheet (1) is annular static pressure elastic strain Pasting some tonometric grating fibers on sheet, some measuring pressure grating fibers (9) are circumferentially uniformly distributed； Transmitting on described double-round axis light strong reflection formula fibre-optical probe (4) and receive the arrangement of optical fiber and be: in optical fiber The heart is a launching fiber, and the periphery of launching fiber is provided with six root receiving fibers and forms first group of reception optical fiber (6), First group of periphery receiving optical fiber (6) is provided with 12 root receiving fibers and forms second group of reception optical fiber (7)；Described Annular static pressure elastic strain sheet (1), circular stagnation pressure elastic strain sheet (2), the first thermometric grating fibers (8) and Second thermometric grating fibers (10) is provided with signal output connecting line.

The light intensity formula of air compressor fluid measuring multiple parameters the most according to claim 1 and raster pattern hybrid fiber sensor, It is characterized in that: described measuring pressure grating fibers (9) is Bragg grating optical fiber.

The light intensity formula of air compressor fluid measuring multiple parameters the most according to claim 1 and raster pattern hybrid fiber sensor, It is characterized in that: described double-round axis light strong reflection formula fibre-optical probe (4) and circular stagnation pressure elastic strain sheet (2) Distance be 0.25mm～2.5mm.

The light intensity formula of air compressor fluid measuring multiple parameters the most according to claim 1 and raster pattern hybrid fiber sensor, It is characterized in that: the outer application high-temperaure coating of described cylindrical metallic package casing (3).

The light intensity formula of air compressor fluid measuring multiple parameters the most according to claim 1 and raster pattern hybrid fiber sensor, It is characterized in that: described annular static pressure elastic strain sheet (1) and circular stagnation pressure elastic strain sheet (2) are selected multiple Close silicon materials.

6. utilizing sensor described in any one of claim 1～5 to carry out a method of testing for compressor gas flow, it is special Levy and be that step is as follows:

Step 1: the light received by receiving optical fiber carries out opto-electronic conversion and gathers, obtains two groups of light intensity receiving light Ratio M (z):

$M\left(z\right)=\exp \left\{\frac{-3\·d^2}{{a_0}^2{\[1+\mathrm{\ζ}{\left(\frac{2z}{a_0}\right)}^{3/2}{\mathrm{tan\θ}}_0\]}^2}\right\}+\exp \left\{\frac{-2\·d^2}{{\mathrm{\σ}}^2{a_0}^2{\[1+\mathrm{\ζ}{\left(\frac{2z}{a_0}\right)}^{3/2}{\mathrm{tan\θ}}_0\]}^2}\right\}$

And obtain the relation between circular stagnation pressure foil gauge displacement z and light intensity ratio M (z), wherein incident optical with connect The distance between axles receiving optical fiber is d, the radius of fibre bundle optical fiber is a₀, the maximum incident angle of optical fiber be θ₀, σ for characterize light The fine relevant parameter of index distribution, ζ are the modulation parameter relevant with light source category and light source and optical fiber coupling condition；

Step 2: according to circular stagnation pressure foil gauge displacement z, calculate stagnation pressure p^*=z* (AE), wherein A is pressure effect Cross-sectional area, E are the elastic modelling quantity of selected materials；

Step 3: use relationship delta λ of strain and wavelength shift_B=(1-P_e)ε·λ_BIt is calculated annular static pressure foil gauge Deformation quantity ε, wherein p_eIt is the strain optical coefficient of optical fiber, λ_BRepresent the centre wavelength of light in grating；

Step 4: dependent variable ε according to cyclic spring foil gauge is proportional with Δ p: ε ∝ Δ p, calculates annular elastomeric Pressure differential deltap p of property foil gauge both sides, obtains static pressure p=Δ p+p*；

Step 5: by the change of the operating ambient temperature that the first thermometric grating fibers (8) records, compensates due to temperature The measurement drift of the elastic strain sheet that change causes, wherein α be the thermal coefficient of expansion of optical fiber, ξ be the hot spectrum of optical fiber Count, Δ λ is the change of wavelength, Δ T is the change of temperature, λ is the centre wavelength of light in grating；Temperature change is in light The relation of grid wavelength change: Δ λ=(α+ξ) λ Δ T；

Step 6: obtained the stagnation temperature T* of compressor by the second thermometric grating fibers (10)；

Step 7: according to p^*, p, T*, calculate gas flow, its computational methods are as follows:

$G=K\frac{p*}{\sqrt{T*}}A{\left(\frac{\mathrm{\κ}+1}{2}\right)}^{\frac{1}{\mathrm{\κ}-1}}\sqrt{\frac{\mathrm{\κ}+1}{\mathrm{\κ}-1}}\sqrt{{\left(\frac{p}{p*}\right)}^{\frac{2}{\mathrm{\κ}}}-{\left(\frac{p}{p*}\right)}^{\frac{\mathrm{\κ}+1}{\mathrm{\κ}}}}$

In formula, K is constant, and κ is gas constant, and A is the pneumatic area measuring cross section, and p* is stagnation pressure, and p is static pressure, T* is stagnation temperature.