A total temperature and total pressure synchronous measurement method and system based on fluorescent optical fiber

Abstract

The present invention relates to a method and system for synchronously measuring total temperature and total pressure using fluorescent optical fibers. The method comprises: generating an excitation light signal and inputting it into a composite fiber core disposed in the airflow path to be measured, wherein the outer surface of the composite fiber core includes a temperature-sensitive coating and a pressure-sensitive coating; obtaining a mixed light signal generated by the airflow to be measured passing through the temperature-sensitive coating and the pressure-sensitive coating; filtering the mixed light signal to obtain a temperature optical signal and a pressure optical signal, and calculating the light intensity ratio to obtain the total temperature and total pressure information of the flow field. Compared with the prior art, the present invention achieves integrated measurement of total temperature and total pressure, and has the advantages of being insensitive to incoming flow angle, high measurement accuracy, and a wide range of application scenarios.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flow field testing, in particular to a total temperature and total pressure synchronous measurement method and system based on fluorescent optical fibers. BACKGROUND

[0002] Accurate measurement of the pressure field and temperature field of the airflow is of great significance for the development of high-performance aeroengines. As important components of aeroengines, the efficiency of compressors and turbines will directly determine the performance of aeroengines. To obtain the efficiency of compressors and turbines, the total temperature and total pressure parameters at the inlet and outlet thereof need to be measured, especially the synchronous measurement of total temperature and total pressure. With the continuous development of aeroengines, the environment inside the compressors and turbines is becoming increasingly complex and diverse, and to achieve fine measurement of the flow field inside the compressors and turbines, higher requirements are put forward for the measurement of total temperature and total pressure.

[0003] Currently, thermocouple sensors are often used for measuring the total temperature of the flow field. However, thermocouples are easily affected by the measurement environment, especially in harsh environments such as high temperature and high humidity, and are susceptible to electromagnetic interference. Moreover, the insensitive angle to the flow direction is small, and the diameter of the wire is thin, which is particularly prone to breakage in high-speed flow fields.

[0004] At the same time, to synchronously obtain the total temperature and total pressure data of a certain region of the flow field, a combined probe integrating two measurement methods is often used. At this time, the size of the probe will increase dramatically, the spatial resolution of the measurement will be greatly reduced, the disturbance of the probe to the flow field will increase, and the measurement of the probe to the narrow space will be limited. Moreover, due to the relatively far spatial position of the sensor, there is a large error between the measurement result and the actual value.

[0005] Chinese patent application publication No. CN115753130A provides an enthalpy probe for obtaining high-enthalpy flow field enthalpy value based on an optical method. A pressure measuring module is arranged on the central axis of the probe head and communicates with an external pressure sensor. A temperature measuring module for measuring the total temperature of the flow field is arranged on one side of the pressure measuring module. That is, a single-hole total pressure probe and an optical fiber total temperature probe are integrated on one probe head to realize synchronous measurement of total temperature and total pressure. However, this integrated method cannot avoid the shortcomings of the combined probe. The size of the probe is too large, which cannot guarantee that the total temperature and total pressure parameters of the synchronous measurement come from the nearest flow line as much as possible. Moreover, the probe has a large disturbance to the test flow field. In addition, the design of the single-hole pressure measurement makes the total pressure measurement sensitive to the flow direction, with a large error, and can only realize steady-state pressure measurement.

[0006] The engine total temperature and total pressure probe and the engine total temperature and total pressure measurement system provided by Chinese patent application publication No. CN115753130A integrate a fiber pressure sensor with a pressure-sensitive unit and a fiber temperature sensor with a temperature-sensitive unit side by side in a stagnation cover to realize synchronous measurement of total temperature and total pressure. Although the probe is completely based on fiber sensors, the two fibers need to be designed side by side, that is, the pressure measuring fiber is in front and the temperature measuring fiber is in back, which also reduces the spatial resolution of the measurement, and the pressure measuring fiber is easily disturbed by the flow caused by the temperature measuring fiber, which increases the total pressure measurement error. At the same time, the stagnation cover inlet is directly opposite the fiber end face, that is, the inlet direction is parallel to the fiber axial direction, so the probe needs to be designed in an L shape when performing actual measurement, which causes fiber bending and also cannot be used to measure the flow field in a narrow area.

[0007] In summary, to solve the problem of fine synchronous measurement of total temperature and total pressure in a complex flow field, it is urgent to develop a method and system that is stable in operation, has a large incoming flow insensitive angle range, has high spatial resolution, has little disturbance to the flow field, and can realize synchronous measurement of total temperature and total pressure in the same area. SUMMARY

[0008] The purpose of the present application is to overcome the defects of the prior art and provide a total temperature and total pressure synchronous measurement method and system based on fluorescent fibers to solve or partially solve the problem of low probe integration caused by separate measurement of total temperature and total pressure.

[0009] The purpose of the present application can be achieved by the following technical solutions:

[0010] In one aspect of the present application, a total temperature and total pressure synchronous measurement method based on fluorescent fibers is provided, comprising the following steps:

[0011] Step S1: generating an excitation light signal and inputting it into a composite end fiber core arranged on a to-be-measured airflow passage, wherein the outside of the composite end fiber core includes temperature-sensitive paint and pressure-sensitive paint;

[0012] Step S2: obtaining a mixed light signal generated by the to-be-measured airflow passing through the temperature-sensitive paint and the pressure-sensitive paint;

[0013] Step S3: filtering temperature optical signals and pressure optical signals from the mixed light signal, and obtaining total temperature information and total pressure information of the flow field by calculating the light intensity ratio.

[0014] In another aspect of the present application, a total temperature and total pressure synchronous measurement system based on fluorescent fibers is provided to realize the aforementioned total temperature and total pressure synchronous measurement method based on fluorescent fibers. The total temperature and total pressure synchronous measurement system comprises:

[0015] A probe head portion is provided with a channel in the axial direction inside, and the probe head portion is provided with an air inlet hole and an air outlet hole.

[0016] a synthetic end fiber core fixed in the channel, the outside of the synthetic end fiber core comprising a temperature-sensitive coating and a pressure-sensitive coating;

[0017] a signal emitting unit for generating an excitation light signal and inputting the synthetic end fiber core;

[0018] a pressure signal receiving unit for collecting a mixed light signal generated by the to-be-measured gas flow passing through the temperature-sensitive coating and the pressure-sensitive coating, and filtering to obtain an optical signal matching the light wavelength of the pressure-sensitive coating;

[0019] a temperature signal receiving unit for collecting a mixed light signal generated by the to-be-measured gas flow passing through the temperature-sensitive coating and the pressure-sensitive coating, and filtering to obtain an optical signal matching the light wavelength of the temperature-sensitive coating;

[0020] a pressure signal processing unit and a temperature signal processing unit for synchronously processing the optical signal matching the light wavelength of the pressure-sensitive coating and the optical signal matching the light wavelength of the temperature-sensitive coating respectively, to obtain total temperature information and total pressure information of the flow field.

[0021] As a preferred technical solution, the temperature-sensitive coating and the pressure-sensitive coating are arranged in intervals, and the pressure-sensitive coating is directly opposite the gas inlet hole.

[0022] As a preferred technical solution, a plurality of gas inlet holes are included, the gas inlet holes are directly opposite the main flow measurement, and are in a cross shape with the center line of the center hole as the symmetric axis, the distance between the center line of the center hole and the top end of the probe head is 0.8mm-5mm, the center line of the circumferential hole is perpendicular to the cylindrical axis and intersects the circumferential cylindrical surface center, the angle between adjacent circumferential holes is 15°-60°, the center line of the axial hole intersects the leeward measurement point of the circumferential cylindrical surface where the center line of the center hole is located, and the angle between adjacent axial holes is 5°-30°.

[0023] As a preferred technical solution, a plurality of gas outlet holes are included, the gas outlet holes are arranged circumferentially, the center lines of the gas outlet holes are parallel and perpendicular to the cylindrical axis, and the distance between the center line of each gas outlet hole and the top end of the probe head is 6mm-16mm.

[0024] As a preferred technical solution, the pressure-sensitive coating is a porous ceramic pressure-sensitive coating or a mesoporous ceramic pressure-sensitive coating, and the temperature-sensitive coating is MFG, Y2O3:Eu, YSZ:Eu, YVO4:Dy or YAG:Dy.

[0025] As a preferred technical solution, the signal emitting unit includes a signal generator and a light source.

[0026] Preferably, the pressure signal receiving unit comprises a pressure signal band-pass optical filter and a pressure signal light detector connected in sequence, and the temperature signal receiving unit comprises a temperature signal band-pass optical filter and a temperature signal light detector connected in sequence.

[0027] Preferably, the total temperature and total pressure synchronous measurement system further comprises:

[0028] An optical fiber coupler is connected with the signal emitting unit through an optical fiber input end, connected with the pressure signal receiving unit and the temperature signal receiving unit through an optical fiber first output end and an optical fiber second output end respectively, and connected with the composite end fiber core through an optical fiber synthesis end.

[0029] Preferably, the total temperature and total pressure synchronous measurement system further comprises:

[0030] A composite end shell is wrapped around one end of the composite end fiber core, and the composite end shell is in abutment with the probe head through insulating glue.

[0031] Compared with the prior art, the present application has at least one of the following beneficial effects:

[0032] (1) Integrated measurement of total temperature and total pressure: the present application is provided with a composite end fiber core comprising temperature-sensitive paint and pressure-sensitive paint, and mixed light signals generated by the temperature-sensitive paint and the pressure-sensitive paint when the gas flow to be measured passes through the temperature-sensitive paint and the pressure-sensitive paint are collected, and temperature optical signals and pressure optical signals are obtained by filtering, and the total temperature information and the total pressure information of the flow field are obtained by calculating the light intensity ratio, thereby realizing integrated measurement of total temperature and total pressure, and through this design, the total temperature and the total pressure at the same position in the flow field can be measured synchronously by using one optical fiber, and the distance between the pressure measurement point and the temperature measurement point is effectively shortened, thereby providing an efficient and accurate means for flow field testing.

[0033] (2) Inflow angle insensitivity: the present application is designed with multiple air inlet holes in a cross shape, so that the measurement results of the probe are not sensitive to a large range of inflow angles and are almost not affected by the direction of the inflow.

[0034] (3) High measurement accuracy: the present application makes full use of the flow characteristics of the gas flow after passing through the air inlet holes, the pressure stagnation effect is best at the position directly opposite the air inlet hole, and the temperature stagnation heat exchange effect is best at the lower end of the air inlet hole, and the layout of spraying pressure-sensitive material at the position directly opposite the air inlet hole and spraying temperature-sensitive material at the lower end of the air inlet hole makes the measurement results more accurate and the measurement precision higher.

[0035] (4) Wide application scenarios: the probe head of the present application has a simple structure and a very small size, which significantly improves the spatial resolution of the measurement, can realize the measurement of various narrow spaces, has little disturbance to the flow field, and is based on fluorescent optical fiber measurement, is not affected by electromagnetic interference, measurement environment humidity, etc., and is suitable for a wide range of measurement environments. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 Flow chart of the total temperature and total pressure synchronous measurement method based on fluorescent optical fiber in the embodiment;

[0037] Figure 2 Schematic diagram of the total temperature and total pressure synchronous measurement system based on fluorescent optical fiber in the embodiment;

[0038] Figure 3 Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment;

[0039] Figure 4 Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Figure 3 Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment;

[0040] Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Figure 5 Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Figure 3 Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment;

[0041] Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Figure 6 Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Figure 3 Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment;

[0042] Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Figure 7 Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Figure 3 Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment;

[0043] Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Figure 8 Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Figure 3 Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment;

[0044] Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Figure 9 Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Figure 6 Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment;

[0045] Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment; Figure 10 Schematic diagram of the total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber in the embodiment;

[0046] Wherein, 01-total temperature and total pressure synchronous measurement probe based on fluorescent optical fiber, 02-signal transmitting unit, 021-signal generator, 022-light source, 03-pressure signal receiving unit, 031-pressure signal band-pass optical filter, 032-pressure signal light detector, 04-temperature signal receiving unit, 041-temperature signal band-pass optical filter, 042-temperature signal light detector, 05-pressure signal processing unit, 06-temperature signal processing unit, 1-probe head, 2-probe stem, 3-inlet hole, 4-outlet hole, 5-channel, 6-composite end fiber core, 7-pressure sensitive paint, 8-temperature sensitive paint, 9-composite end shell, 10-insulating glue, 11-optical fiber composite end, 12-optical fiber input end, 13-optical fiber first output end, 14-optical fiber second output end, 15-optical fiber coupler. DETAILED DESCRIPTION

[0047] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts should fall within the protection scope of the present application.

[0048] In the description of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings or the orientation or positional relationship commonly used when the product of the present application is used, and are merely for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. For example, "horizontal" only means that its direction is relatively more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly inclined.

[0049] In addition, the terms "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first" and "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0050] Embodiment 1

[0051] The prior art has the following problems:

[0052] (1) The existing single-form probe cannot realize the simultaneous measurement of total temperature and total pressure in the same area of the flow field.

[0053] (2) The existing combined probe has a large size, causes large disturbance to the flow field, has low spatial resolution, and is difficult to measure in a narrow area.

[0054] (3) The measurement results of the existing temperature probe and combined probe are affected by the flow direction, and the angle of insensitivity to the flow is small.

[0055] (4) The commonly used temperature probe is easily affected by electromagnetic interference, and has large measurement error in harsh environments such as high temperature and high humidity.

[0056] In view of the foregoing problems, the present embodiment provides a total temperature and total pressure synchronous measurement method based on fluorescent optical fiber, as shown in Figure 1 The method comprises the following steps:

[0057] Step S1, generate excitation light signal and input into the synthetic end fiber core arranged on the gas flow passage to be measured, wherein the outside of the synthetic end fiber core comprises temperature-sensitive paint and pressure-sensitive paint;

[0058] Step S2, obtain mixed light signal generated by the temperature-sensitive paint and the pressure-sensitive paint when the gas flow to be measured passes through the temperature-sensitive paint and the pressure-sensitive paint;

[0059] Step S3, filter the mixed light signal to obtain temperature optical signal and pressure optical signal, and obtain total temperature information and total pressure information of the flow field by calculating the light intensity ratio.

[0060] To realize the above method, refer to Figure 2 The embodiment also provides a total temperature and total pressure synchronous measurement system based on fluorescent optical fibers, which comprises a total temperature and total pressure synchronous measurement probe 01 based on fluorescent optical fibers, a signal emitting unit (02), a pressure signal receiving unit 03, a temperature signal receiving unit 04, a pressure signal processing unit 05 and a temperature signal processing unit 06, and the following will be described respectively.

[0061] Refer to Figure 3 It is a schematic view of the total temperature and total pressure synchronous measurement probe 01 based on fluorescent optical fibers, which comprises a probe head 1, a probe support rod 2, an air inlet hole 3, an air outlet hole 4, a channel 5, a synthetic end fiber core 6, pressure-sensitive paint 7, temperature-sensitive paint 8, a synthetic end shell 9, insulating glue 10, an optical fiber synthetic end 11, an optical fiber input end 12, an optical fiber first output end 13, an optical fiber second output end 14 and an optical fiber coupler 15.

[0062] The probe head 1 is composed of a cylinder and a rapidly converging curve rotating body, the air inlet hole 3 is arranged on the front side of the main flow of the probe head 1, the air outlet hole 4 is arranged on the back side of the main flow of the probe head 1, the channel 5 is arranged in the probe head 1 along the axial direction and penetrates through the whole probe. Figure 8 The channel 5 is internally provided with the optical fiber synthetic end 11, refer to Figure 4 It is a partial schematic view of the synthetic end fiber core, the synthetic end fiber core 6 at the top end of the optical fiber synthetic end 11 is sprayed with the pressure-sensitive paint 7 and the temperature-sensitive paint 8 from top to bottom, the optical fiber synthetic end 11 extends out of the tail of the probe support rod 2 and is coupled with the optical fiber input end 12, the optical fiber first output end 13 and the optical fiber second output end 14 through the optical fiber coupler 15.

[0063] The diameter d of the cylinder of the probe head 1 is in the range of 1mm≤d≤6mm, the length is 10mm-45mm, the curve rotating body can be selected from a circular arc line, a double torsion line or a conic curve, the diameter of the circular channel 5 in the probe head 1 is 0.5mm-5mm, and 3mm is selected in the embodiment.

[0064] Refer to Figure 5, the probe head 1 cylinder is provided with air inlet holes 3 on the side opposite to the main flow side, the diameter of the air inlet holes 3 is 0.3mm-3mm, 1.0mm is selected in the embodiment, the number of the air inlet holes 3 is 5-10, 5 is selected in the embodiment, and the center lines of the center holes are taken as the symmetrical axes to form a cross shape, the distance from the center lines of the center holes to the top end of the probe head 1 is 0.8mm-5mm, 3.8mm is selected in the embodiment, see Figure 7 , the center lines of the circumferential holes are perpendicular to the cylinder axis and intersect at the center of the circumferential cylinder surface, the angle between adjacent circumferential holes is 15°-60°, 35° is selected in the embodiment, the center lines of the axial holes intersect at the leeward measuring point of the circumferential cylinder surface where the center lines of the center holes are located, the angle between adjacent axial holes is 5°-30°, 15° is selected in the embodiment.

[0065] See Figure 6 , the probe head 1 cylinder is provided with air outlet holes 4 on the side opposite to the main flow side, the diameter of the air outlet holes 4 is 0.2mm-2mm, 0.6mm is selected in the embodiment, the number of the air outlet holes 4 is 1-3, 2 is selected in the embodiment, and the air outlet holes 4 are arranged in a straight line in the circumferential direction, see Figure 9 , the center lines of the air outlet holes 4 are parallel and perpendicular to the cylinder axis, the distance from the center lines of the air outlet holes 4 to the top end of the probe head 1 is 6mm-16mm, 10mm is selected in the embodiment.

[0066] The probe support rod 2 is a cylinder, the diameter D of the cylinder, the value range of D is 2mm≤D≤8mm;

[0067] The diameter of the fiber synthesis end 11 is 0.5mm-3mm, 1mm is selected in the embodiment, the fiber synthesis end 11 is composed of a synthesis end core 6 and a synthesis end shell 9, the diameter of the synthesis end core 6 is 0.2mm-2mm, 0.5mm is selected in the embodiment, the length of the exposed synthesis end core 6 at the top of the fiber synthesis end 11 is 2mm-8mm, 6mm is selected in the embodiment, the insulating glue 10 realizes the fixation of the fiber synthesis end 11 and the probe head 1, the tail of the fiber synthesis end 11 is coupled with the fiber input end 12, the fiber first output end 13 and the fiber second output end 14 through the fiber coupler 15, and the diameters of the fiber input end 12, the fiber first output end 13 and the fiber second output end 14 are all 0.2mm-2.5mm, 0.4mm is selected in the embodiment.

[0068] The pressure sensitive paint 7 is sprayed on the upper part of the exposed synthesis end core 6 opposite to the air inlet holes 3, and emits excitation light carrying pressure information after being excited by input light, the pressure sensitive paint 7 can be selected as porous ceramic pressure sensitive paint PC-PSP or mesoporous ceramic pressure sensitive paint MP-PSP, the spraying length is 0.5mm-4mm, 2.9mm is selected in the embodiment, and the spraying thickness is 0.003mm-0.01mm, 0.005mm is selected in the embodiment.

[0069] The temperature-sensitive coating 8 is sprayed on the lower part of the bare synthetic end core 6, and emits excitation light carrying temperature information after being excited by input light. The temperature-sensitive coating 8 is selected from transition metal-doped oxides, rare earth element-doped oxides or other suitable temperature-sensitive materials, and can be selected from MFG, Y2O3:Eu, YSZ:Eu, YVO4:Dy or YAG:Dy. The spraying length is 0.5 mm-4 mm, and the spraying thickness is 0.001 mm-0.01 mm. In this embodiment, the spraying length is 12.8 mm, and the spraying thickness is 0.005 mm.

[0070] It should be noted that the selected pressure-sensitive coating and temperature-sensitive coating need to have different excitation light wavelengths to distinguish the pressure optical signal and the temperature optical signal. The pressure band-pass optical filter in the pressure signal receiving unit filters out the background light and the non-pressure optical signal, and finally obtains the total pressure data. The temperature band-pass optical filter in the temperature signal receiving unit filters out the background light and the non-temperature optical signal, and finally obtains the total temperature data, and then the total temperature and total pressure data of the incoming flow can be obtained synchronously.

[0071] In use, the probe is placed in the measured flow field, and the incoming flow stagnates at the synthetic core end opposite the inlet hole. The pressure-sensitive coating measures the total pressure of the incoming flow, and the excitation light intensity of the pressure-sensitive coating satisfies the following relationship:

[0072]

[0073] In the formula, I represents the light intensity, P represents the pressure, the subscript ref represents the reference state, and A and B are related coefficients. The relationship between the light intensity and the pressure can be obtained by calibration, and then the total pressure of the incoming flow can be obtained.

[0074] The kinetic energy of the gas flow at the synthetic end core where the temperature-sensitive coating is sprayed is completely converted into heat energy, and the temperature-sensitive coating measures the total temperature of the incoming flow. The excitation light intensity of the temperature-sensitive coating satisfies the following relationship:

[0075]

[0076] In the formula, I represents the light intensity, T represents the pressure, the subscript ref represents the reference state, and the function f can be selected as a polynomial, exponential or other function form to fit the relationship between the light intensity and the temperature, and then the total temperature of the incoming flow can be obtained.

[0077] The signal transmitting unit includes a light source 022 and a signal generator 021, which are used to excite the pressure-sensitive coating 7 and the temperature-sensitive coating 8. The light source 022 is an ultraviolet laser or a blue laser, and the wavelength range is 260 nm-600 nm. In this embodiment, the wavelength is 405 nm, the power is 15 w, the width of the pulse light is 20 ms, and the pulse period is 1000 ms.

[0078] The pressure signal receiving unit 03 comprises a pressure signal band-pass optical filter 031 and a pressure signal light detector 032. The pressure signal band-pass optical filter 031 is used to filter out background light and non-pressure optical signals, and the pressure signal light detector 032 is a photodiode or a photomultiplier tube, and the photomultiplier tube is selected in the embodiment.

[0079] The temperature signal receiving unit 04 comprises a temperature signal band-pass optical filter 041 and a temperature signal light detector 042. The temperature signal band-pass optical filter 041 is used to filter out background light and non-temperature optical signals, and the temperature signal light detector 042 is a photodiode or a photomultiplier tube, and the photomultiplier tube is selected in the embodiment.

[0080] The pressure signal processing unit 05 is used to process the pressure optical signal output by the pressure signal light detector 032 and calculate the light intensity ratio to obtain pressure information.

[0081] The temperature signal processing unit 06 is used to process the temperature optical signal output by the temperature signal light detector 042 and calculate the light intensity ratio to obtain temperature information.

[0082] Preferably, the probe further comprises a calibration system for periodically calibrating the pressure corresponding characteristics of the pressure-sensitive paint 7 and the temperature response characteristics of the temperature-sensitive paint 8.

[0083] In the embodiment, the pressure-sensitive fluorescent material or the temperature-sensitive fluorescent material is sprayed on the surface of the object to be measured to realize the pressure and temperature measurement of the characteristic region. The embodiment combines the fluorescent pressure measurement and the fluorescent temperature measurement technology, uses the probe based on the fluorescent optical fiber to meet the flow field measurement requirements, integrates the pressure-sensitive paint and the temperature-sensitive paint, and plays the maximum advantage of the optical fiber sensor. The total temperature and the total pressure can be measured in the same region and at the same time.

[0084] The working process of the system comprises the following steps:

[0085] (1) The total temperature and total pressure synchronous measurement probe 01 based on the fluorescent optical fiber is placed in the measured flow field, and the inlet hole 3 is directly opposite to the flow direction;

[0086] (2) The laser emitted by the signal emitting unit 02 enters the optical fiber synthesis end 11 through the optical fiber input end 12, and is used to excite the pressure-sensitive paint 7 and the temperature-sensitive paint 8;

[0087] (3) The high-speed airflow stagnates at the synthetic end fiber core 6 of the sprayed pressure-sensitive paint 7 opposite the air inlet hole 3, the pressure-sensitive paint 7 is excited by the input light, excitation light carrying pressure information is generated and output through the first output end 13 of the optical fiber, and then transmitted to the pressure signal processing unit 05 through the pressure signal receiving unit 03;

[0088] (4) The high-speed airflow completely converts kinetic energy into heat energy at the synthetic end fiber core 6 of the sprayed temperature-sensitive paint 8, the temperature-sensitive paint 8 is excited by the input light, excitation light carrying temperature information is generated and output through the second output end 14 of the optical fiber, and then transmitted to the temperature signal processing unit 06 through the temperature signal receiving unit 04;

[0089] (5) The pressure signal processing unit 05 and the temperature signal processing unit 06 respectively process the synchronous optical signals carrying pressure and temperature information, and then obtain total temperature and total pressure data of the flow field.

[0090] The method / system has the following beneficial effects:

[0091] (1) After temperature and pressure calibration, the total temperature and total pressure at the same position in the flow field can be measured synchronously by using one optical fiber, which provides an efficient and accurate means for flow field testing.

[0092] (2) The probe has a cross-shaped multi-air inlet hole design, so that the insensitive angle range of the probe measurement result to the incoming flow is large, and is almost not affected by the direction of the incoming flow.

[0093] (3) The probe fully utilizes the flow characteristics of the airflow after passing through the air inlet hole, the pressure stagnation effect is best opposite the air inlet hole, and the temperature stagnation heat exchange effect is best at the lower end of the air inlet hole. The layout of spraying pressure-sensitive materials opposite the air inlet hole and spraying temperature-sensitive materials at the lower end of the air inlet hole makes the measurement result more accurate and the measurement precision higher.

[0094] (4) The probe head structure is simple and the size is very small, which significantly improves the spatial resolution of the measurement, can realize the measurement of various narrow spaces, and has small disturbance to the flow field.

[0095] (5) The probe is based on fluorescent optical fiber measurement, is not affected by electromagnetic interference, measurement environment humidity, etc., and is suitable for a wide range of measurement environments.

[0096] Embodiment 2

[0097] Referring to Figure 10 , the embodiment provides an electronic device, which comprises a processor, an internal bus, a network interface, a memory and a non-volatile memory on the hardware level. Of course, it can also include other hardware required by the business. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs to realize the above Figure 1 The method for synchronous measurement of total temperature and total pressure.

[0098] Embodiment 3

[0099] This embodiment provides a computer-readable storage medium including one or more programs for execution by one or more processors of an electronic device, the one or more programs including instructions for performing the method of total temperature and total pressure synchronous measurement as described above. Figure 1

[0100] The above description is merely that of a specific implementation of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present application, and these modifications or replacements should be encompassed within the scope of protection of the present application. Therefore, the scope of protection of the present application should be subject to the scope of protection of the claims.​

Claims

1. A method for synchronously measuring total temperature and total pressure based on fluorescent optical fiber, characterized in that: The steps include: Step S1, generating an excitation light signal and inputting the signal into a synthetic end fiber core provided on the airflow path to be measured, wherein the outer side of the synthetic end fiber core includes a temperature-sensitive coating and a pressure-sensitive coating; Step S2, obtaining a mixed light signal generated by the airflow to be measured passing through the temperature-sensitive coating and the pressure-sensitive coating; Step S3: filtering the mixed optical signal to obtain a temperature optical signal and a pressure optical signal, and calculating the light intensity ratio to obtain total temperature information and total pressure information of the flow field.

2. A total temperature and total pressure synchronous measurement system based on fluorescent optical fiber, characterized in that: For implementing the total temperature and total pressure synchronous measurement method based on fluorescent optical fiber as claimed in claim 1, the total temperature and total pressure synchronous measurement system comprises: A probe head (1) is provided with a channel (5) in the axial direction, and an air inlet (3) and an air outlet (4) are provided on the probe head (1); A synthetic end fiber core (6) is fixed in the channel (5), and the outer side of the synthetic end fiber core (6) includes a temperature-sensitive coating (8) and a pressure-sensitive coating (7); A signal transmitting unit (02) is used to generate an excitation light signal and input the signal into the synthesis end fiber core (6); A pressure signal receiving unit (03) is used to collect a mixed optical signal generated by the airflow to be measured passing through the temperature-sensitive coating (8) and the pressure-sensitive coating (7), and filter the mixed optical signal to obtain an optical signal that matches the optical wavelength of the pressure-sensitive coating (7); A temperature signal receiving unit (04) is used to collect a mixed optical signal generated by the airflow to be measured passing through the temperature-sensitive coating (8) and the pressure-sensitive coating (7), and filter the mixed optical signal to obtain an optical signal that matches the wavelength of the light of the temperature-sensitive coating (8); The pressure signal processing unit (05) and the temperature signal processing unit (06) are used to synchronously process the optical signal matching the optical wavelength of the pressure-sensitive coating (7) and the optical signal matching the optical wavelength of the temperature-sensitive coating (8), respectively, to obtain the total temperature information and the total pressure information of the flow field. The invention comprises a plurality of the air inlet holes (3), the air inlet holes (3) are directly facing the main flow measurement, and are in a cross shape with the center line of the center hole as the axis of symmetry, the center line of the center hole is 0.8 mm to 5 mm away from the top of the probe head (1), the center lines of the holes arranged along the circumferential direction are perpendicular to the axis of the cylinder and intersect at the center of the circumferential cylindrical surface, the angle between adjacent circumferential holes is 15° to 60°, the center lines of the holes arranged along the axial direction intersect at the leeward measuring point of the circumferential cylindrical surface where the center line of the center hole is located, and the angle between adjacent axial holes is 5° to 30°.

3. The total temperature and total pressure synchronous measurement system based on fluorescent optical fiber according to claim 2, characterized in that: The temperature-sensitive coating (8) and the pressure-sensitive coating (7) are arranged at intervals, and the pressure-sensitive coating (7) faces the air inlet (3).

4. The total temperature and total pressure synchronous measurement system based on fluorescent optical fiber according to claim 2, characterized in that: The invention comprises a plurality of the air outlet holes (4), wherein the air outlet holes (4) are arranged along the circumferential direction, the center lines of the air outlet holes (4) are parallel and perpendicular to the axis of the cylinder, and the distance between the center lines of the air outlet holes (4) and the top of the probe head is 6 mm to 16 mm.

5. The total temperature and total pressure synchronous measurement system based on fluorescent optical fiber according to claim 2, characterized in that: The pressure-sensitive coating (7) is a porous ceramic pressure-sensitive coating or a mesoporous ceramic pressure-sensitive coating, and the temperature-sensitive coating (8) is MFG, Y2O3:Eu, YSZ:Eu, YVO4:Dy or YAG:Dy.

6. The total temperature and total pressure synchronous measurement system based on fluorescent optical fiber according to claim 2, characterized in that: The signal transmitting unit (02) comprises a signal generator (021) and a light source (022).

7. The total temperature and total pressure synchronous measurement system based on fluorescent optical fiber according to claim 2, characterized in that: The pressure signal receiving unit (03) comprises a pressure signal bandpass optical filter (031) and a pressure signal light detector (032) connected in sequence, and the temperature signal receiving unit (04) comprises a temperature signal bandpass optical filter (041) and a temperature signal light detector (042) connected in sequence.

8. The total temperature and total pressure synchronous measurement system based on fluorescent optical fiber according to claim 2, characterized in that: The total temperature and total pressure synchronous measurement system further includes: The optical fiber coupler (15) is connected to the signal transmitting unit (02) via the optical fiber input end (12), is connected to the pressure signal receiving unit (03) and the temperature signal receiving unit (04) via the optical fiber first output end (13) and the optical fiber second output end (14), and is connected to the synthesis end fiber core (6) via the optical fiber synthesis end (11).

9. The total temperature and total pressure synchronous measurement system based on fluorescent optical fiber according to claim 2, characterized in that: The total temperature and total pressure synchronous measurement system further includes: The synthetic end shell (9) wraps one end of the synthetic end fiber core (6) therein, and the synthetic end shell (9) abuts against the probe head (1) through an insulating glue (10).

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