Rotary disc sinusoidal temperature generator and frequency domain analysis method

Abstract

The application discloses a rotary table type sinusoidal temperature generator and a frequency domain analysis method, and belongs to the field of temperature measurement. The rotary table type sinusoidal temperature generator comprises a rotary table, a servo motor, a front cold air pipe, a hot calibration air tunnel, a temperature sensor, a pressure sensor, a flowmeter, a cold air bypass and an adjusting valve. The rotary table is disc-shaped, a circular hole is arranged at the center of the rotary table, the diameter of the circular hole is matched with the motor shaft, and a plurality of special-shaped holes are arranged around the circular hole. The double-row special-shaped holes are used as the window of the cold air flow on the rotary table, the cold air flow is modulated with the hot air flow in the hot air tunnel, and the air flow temperature changing according to the sinusoidal law is formed. The frequency domain analysis method forms the air flow temperature changing according to the sinusoidal law through the rotary table type sinusoidal temperature generator, the amplitude-frequency characteristic and the phase-frequency characteristic of the air flow temperature sensor are analyzed under the air flow temperature changing according to the sinusoidal law, and the dynamic characteristic calibration of the air flow temperature under the sinusoidal temperature excitation is realized. The application has the advantages of fast response, low waveform distortion and high practicability.

Description

TECHNICAL FIELD

[0001] The present application relates to a rotary disc type sinusoidal temperature generator, which is suitable for dynamic characteristic calibration of airflow temperature sensor under sinusoidal temperature excitation, and belongs to the field of temperature measurement. BACKGROUND

[0002] There are many dynamic performance indicators of temperature sensor, such as time constant, natural frequency and damping ratio. At present, time constant is mainly used to evaluate the dynamic characteristics of temperature sensor, and the time constant of the sensor is obtained by dynamic calibration of the temperature sensor on a step dynamic temperature standard device. The time constant can reflect the lag time of the temperature sensor, but it cannot give the dynamic error of the temperature sensor caused by thermal lag, i.e. amplitude sensitivity error, so it cannot comprehensively and accurately evaluate the dynamic performance of the temperature sensor, and it cannot perform frequency domain analysis. In addition, many temperature sensors are installed downstream of rotating parts, and the measured temperature is a periodic sinusoidal signal. In order to ensure the accuracy and reliability of the sinusoidal temperature measurement result, a sinusoidal dynamic temperature generator needs to be developed to provide sinusoidal dynamic temperature excitation for the temperature sensor, simulate the actual use condition, calibrate the sensor dynamically, obtain the amplitude-frequency characteristic and phase-frequency characteristic (including natural frequency and damping ratio) of the sensor, and compensate and correct the measurement result of the temperature sensor on the basis of the calibration result. At present, there is no sinusoidal dynamic temperature generator in China, and the above calibration cannot be completed. SUMMARY

[0003] The rotary disc type sinusoidal temperature generator disclosed in the present application solves the technical problem of forming airflow temperature changing according to sinusoidal law and realizing dynamic characteristic calibration of airflow temperature under sinusoidal temperature excitation.

[0004] In order to solve the problem that the amplitude-frequency characteristic and phase-frequency characteristic of the airflow temperature sensor cannot be effectively obtained at present, the present application further discloses a frequency domain analysis method, which is realized based on the rotary disc type sinusoidal temperature generator, can realize amplitude-frequency characteristic and phase-frequency characteristic analysis of the airflow temperature sensor, and has the advantages of fast response and low waveform distortion.

[0005] The purpose of the present application is realized by the following technical solutions.

[0006] The rotary disc type sinusoidal temperature generator disclosed in the present application comprises a rotary disc, a servo motor, a cold air pipe in front of the disc, a hot calibration wind tunnel, a temperature sensor, a pressure sensor, a flow meter, a cold air bypass and an adjusting valve.

[0007] The rotary disc is disc-shaped, a circular hole is arranged at the center position, the diameter of the circular hole matches the motor shaft, a plurality of special-shaped holes are arranged around the circular hole, the area of the special-shaped hole is calculated by wherein c ph is the constant pressure specific heat capacity of hot air in the hot calibration wind tunnel, m his the mass flow of the hot gas, t h is the temperature of the hot gas, t pc is the specific heat capacity at constant pressure of the cold gas, t c is the density of the cold gas, t c is the velocity of the cold gas, t c is the temperature of the cold gas, t m is the amplitude of the modulated sinusoidal temperature, t a is the initial phase of the modulated sinusoidal temperature, α is the angle turned by the rotating disc. The above parameters c ph , c pc , ρ c are inherent parameters of the gas medium, m h , t h , u c , t c are working parameters of the experiment, t m , t a are structural parameters of the rotating disc, and the determination of the structural parameters needs to meet the conditions of t m sinα≤t h -t a .

[0008] The rotating disc is made of metal or alloy with high specific strength, and preferably, the rotating disc is made of titanium or aluminum.

[0009] The number of the special-shaped holes of the rotating disc is calculated by f , wherein f is the frequency of the sinusoidal temperature, and n is the rotating speed of the motor.

[0010] Preferably, the special-shaped holes are arranged in two rows in a staggered manner, and the minimum radial distance between the two rows of special-shaped holes is 0.8-1.2 times the thickness of the rotating disc.

[0011] The rotating disc is installed on the shaft of the servo motor and is arranged outside the hot calibration wind tunnel, the axial direction of the rotating disc is perpendicular to the axial direction of the hot calibration wind tunnel, the outlet of the cold gas pipe in front of the disc is aligned with the special-shaped holes of the rotating disc, and the axial lines of the two are parallel, temperature sensors are installed on the hot calibration wind tunnel, temperature sensors, pressure sensors, flow meters and regulating valves are installed on the cold gas pipe in front of the disc, and a cold gas bypass is connected upstream of the regulating valve, and a regulating valve is also installed on the cold gas bypass.

[0012] The end of the cold gas pipe in front of the disc is provided with a circular rotating flat structure, which covers the inner and outer boundaries of the special-shaped holes in the radial direction, and the circumferential width is equal to the circumferential width of the special-shaped holes.

[0013] The application further discloses a frequency domain analysis method, which is realized based on the rotating disc type sinusoidal temperature generator. The frequency domain analysis method comprises the following steps:

[0014] Step one: place the standard temperature sensor in the core area of the hot calibration wind tunnel, set the rotating disc speed, collect the response characteristic curve of the standard temperature sensor at the corresponding frequency, and draw the amplitude-frequency characteristic curve and the phase-frequency characteristic curve of the standard temperature sensor according to the response characteristic curve.

[0015] Step two: replace the standard temperature sensor with the calibrated temperature sensor, collect the response characteristic curve of the calibrated temperature sensor at the same rotating disc speed, and draw the amplitude-frequency characteristic curve and the phase-frequency characteristic curve of the calibrated temperature sensor according to the response characteristic curve.

[0016] Step three: take the double-row special-shaped holes as the window of the cold air flow on the rotating disc, modulate the hot air flow in the hot wind tunnel to form the air flow temperature changing according to the sine law, and use the air flow temperature sensor for dynamic characteristic calibration; change the rotating disc speed of the generator, collect the response characteristic curve of the standard temperature sensor and the calibrated temperature sensor at the corresponding frequency, respectively, draw the amplitude-frequency characteristic curve and the phase-frequency characteristic curve of the standard temperature sensor and the calibrated temperature sensor, respectively, according to the response characteristic curve. The amplitude-frequency characteristic and the phase-frequency characteristic of the air flow temperature sensor are analyzed under the air flow temperature changing according to the sine law, and the dynamic characteristic calibration of the air flow temperature under the sine temperature excitation is realized.

[0017] Advantages:

[0018] 1. The rotating disc type sine temperature generator disclosed in the application takes the double-row special-shaped holes as the window of the cold air flow on the rotating disc, modulates the hot air flow in the hot wind tunnel to form the air flow temperature changing according to the sine law, and uses the air flow temperature sensor for dynamic characteristic calibration.

[0019] 2. The application also discloses a frequency domain analysis method, which forms the air flow temperature changing according to the sine law through the rotating disc type sine temperature generator, analyzes the amplitude-frequency characteristic and the phase-frequency characteristic of the air flow temperature sensor under the air flow temperature changing according to the sine law, and realizes the dynamic characteristic calibration of the air flow temperature under the sine temperature excitation. The rotating disc type sine temperature generator has the advantages of fast response and low waveform distortion.

[0020] 3. The application also discloses a frequency domain analysis method, which constructs the relationship formula of the area of the special-shaped hole and the parameters c ph 、c pc 、ρ c 、m h 、t h 、u c 、t c The above parameters c ph 、c pc 、ρ c are inherent parameters of the gas medium, and m h 、t h ​u c t c is the working condition parameter of the test, t m t a is the structural parameter of the rotating disc, and the determination of the structural parameter satisfies the condition that t m sinα≤t h -t a The condition, in combination with the above-mentioned relationship, the quantitative adjustment of the rotating disc speed makes the airflow temperature change according to the sine rule, so that the frequency domain analysis has the advantages of fast response and low waveform distortion. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a structural schematic diagram of the rotating disc type sine temperature generator of the present application;

[0022] Figure 2 is a structural schematic diagram of the rotating disc;

[0023] Figure 3 is a structural schematic diagram of the end of the front disc cold gas pipe;

[0024] Wherein: 1-rotating disc, 2-servo motor, 3-front disc cold gas pipe, 4-hot calibration wind tunnel, 5-temperature sensor, 6-pressure sensor, 7-flow meter, 8-cold gas bypass, 9-regulating valve. DETAILED DESCRIPTION

[0025] In order to better illustrate the purpose and advantages of the present application, the content of the application is further described below in combination with the drawings and examples.

[0026] As Figure 1 shown, the rotating disc type sine temperature generator disclosed in the embodiment comprises a rotating disc 1, a servo motor 2, a front disc cold gas pipe 3, a hot calibration wind tunnel 4, a temperature sensor 5, a pressure sensor 6, a flow meter 7, a cold gas bypass 8 and a regulating valve 9.

[0027] The rotating disc 1 is disc-shaped, with a disc diameter of 240mm and a thickness of 10mm. A circular through hole with a diameter of 20mm is designed at the center of the disc, and 28 irregular holes are designed around the hole. The area of the irregular hole is calculated by , wherein α is the angle of rotation of the rotating disc. The material of the rotating disc is selected from aluminum alloy 2A01.

[0028] The irregular holes are arranged in two rows in a staggered manner, and the radial spacing between the two rows of irregular holes is 10mm.

[0029] As Figure 2As shown, the rotating disc 1 is installed on the shaft of the servo motor 2, placed outside the opening of the hot calibration wind tunnel 4, the axis direction of the rotating disc 1 is perpendicular to the axis direction of the hot calibration wind tunnel 4, the outlet of the pre-disc cold gas pipe 3 is aligned with the special-shaped hole of the rotating disc 1, and the axis directions of the two are parallel, the temperature sensor 5 is installed on the hot calibration wind tunnel 4, the temperature sensor 5, the pressure sensor 6, the flow meter 7, and the adjusting valve 9 are installed on the pre-disc cold gas pipe 3, and the cold gas bypass 8 is connected upstream of the adjusting valve 9. The adjusting valve 9 is also installed on the cold gas bypass 8.

[0030] As shown in the figure, Figure 3 As shown, the end of the pre-disc cold gas pipe is provided with a circular flat hole structure, the inner diameter of the circular hole is 30mm, the length of the flat hole is 30mm, and the width is 15mm.

[0031] The frequency domain analysis method of the embodiment is realized based on the rotating disc type sinusoidal temperature generator. The specific implementation steps of the frequency domain analysis method are as follows:

[0032] Step one: place the standard temperature sensor in the core area of the hot calibration wind tunnel, set the rotating speed of the rotating disc type sinusoidal temperature generator to 1286r / min, then the corresponding frequency is 10Hz, use the high-speed acquisition device to collect the response characteristic curve of the standard temperature sensor, take the amplitude in the response characteristic curve as the vertical coordinate and the frequency as the horizontal coordinate to draw the amplitude-frequency characteristic curve of the standard temperature sensor, and take the phase in the response characteristic curve as the vertical coordinate and the frequency as the horizontal coordinate to draw the phase-frequency characteristic curve of the standard temperature sensor.

[0033] Step two: replace the standard temperature sensor with the calibrated temperature sensor, under the same rotating speed of the rotating disc 1, use the same method to collect the response characteristic curve of the calibrated temperature sensor, and draw the amplitude-frequency characteristic curve and the phase-frequency characteristic curve of the calibrated temperature sensor.

[0034] Step three: change the rotating speed of the generator to 2572r / min, 3858r / min, 5144r / min, and 6430r / min respectively, then the corresponding frequencies are 20Hz, 30Hz, 40Hz, and 50Hz respectively, use the high-speed acquisition device to collect the response characteristic curves of the standard temperature sensor and the calibrated temperature sensor under each frequency respectively, take the amplitude in the response characteristic curve as the vertical coordinate and the frequency as the horizontal coordinate to draw the amplitude-frequency characteristic curves of the standard temperature sensor and the calibrated temperature sensor, and take the phase in the response characteristic curve as the vertical coordinate and the frequency as the horizontal coordinate to draw the phase-frequency characteristic curves of the standard temperature sensor and the calibrated temperature sensor. The airflow temperature sensor amplitude-frequency characteristic and phase-frequency characteristic analysis are carried out under the airflow temperature changing in accordance with the sinusoidal law, and the dynamic characteristic calibration of the airflow temperature under the sinusoidal temperature excitation is realized.

[0035] The above detailed description of the specific description, the purpose, technical scheme and beneficial effects of the application are further described in detail, it should be understood that the above description is only a specific embodiment of the present application, and is not used to limit the protection scope of the present application, any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A turntable sinusoidal temperature generator characterised in that: The rotating disc, servo motor, cold air pipe in front of the disc, hot calibration wind tunnel, temperature sensor, pressure sensor, flow meter, cold air bypass and regulating valve are included. The rotating disc is disc-shaped, and a circular hole is arranged at the center position, the diameter of the circular hole matches the motor shaft, a plurality of special-shaped holes are arranged around the circular hole, the area of the special-shaped holes is used to calculate c ph , the specific heat capacity of the hot air in the hot calibration wind tunnel at constant pressure, m h is the mass flow of the hot air flow, t h is the temperature of the hot air flow, c pc is the specific heat capacity of the cold air at constant pressure, p c is the density of the cold air, u c is the speed of the cold air flow, t c is the temperature of the cold air flow, t m is the amplitude of the modulated sinusoidal temperature, t a is the initial phase of the modulated sinusoidal temperature, and a is the angle through which the rotating disc rotates; in the above parameters, c ph , c pc , p c are inherent parameters of the gas medium, m h , t h , u c , t c are working condition parameters of the test, t m , t a are structure parameters of the rotating disc, and the determination of the structure parameters needs to meet the conditions of t m sin a ≤ t h -t a . The number of the special-shaped holes of the turntable is used where f is the frequency of the sinusoidal temperature, and n is the motor rotation speed. The two rows of special-shaped holes are staggered, and the minimum radial distance between the two rows of special-shaped holes is 0.8-1.2 times the thickness of the rotating disc. The two rows of special-shaped holes are used as the window of the cold air flow on the rotating disc, and the hot air flow in the hot wind tunnel is modulated to form the air flow temperature changing according to the sine rule, which is used for dynamic characteristic calibration of the air flow temperature sensor.

2. The turntable sinusoidal temperature generator of claim 1, wherein: The rotating disc is made of titanium, aluminum or alloy.

3. The turntable sinusoidal temperature generator of claim 1, wherein: The rotating disc is installed on the shaft of the servo motor and placed outside the hot calibration wind tunnel, the axis direction of the rotating disc is perpendicular to the axis direction of the hot calibration wind tunnel, the outlet of the cold air pipe in front of the disc is aligned with the special-shaped hole of the rotating disc, and the axis directions of the two are parallel, the temperature sensor is installed on the hot calibration wind tunnel, the temperature sensor, pressure sensor, flow meter and regulating valve are installed on the cold air pipe in front of the disc, the cold air bypass is connected upstream of the regulating valve, and the regulating valve is also installed on the cold air bypass.

4. The turntable sinusoidal temperature generator of claim 1, wherein: The end of the cold air pipe in front of the disc is provided with a circular rotating flat structure covering the inner and outer boundaries of the special-shaped hole in the radial direction, and the circumferential width is equal to the circumferential width of the special-shaped hole.

5. A method of frequency domain analysis, implemented on the basis of a rotating disc sinusoidal temperature generator as claimed in claim 1, 2, 3 or 4, characterized in that: The method comprises the following steps, Step one: the standard temperature sensor is placed in the core area of the hot calibration wind tunnel, the rotating speed of the rotating disc of the rotating disc type sine temperature generator is set, the response characteristic curve of the standard temperature sensor at the corresponding frequency of the rotating speed is collected, and the amplitude-frequency characteristic curve and the phase-frequency characteristic curve of the standard temperature sensor are drawn according to the response characteristic curve; Step two: the standard temperature sensor is replaced by the calibrated temperature sensor, and the response characteristic curve of the calibrated temperature sensor is collected at the same rotating speed of the rotating disc, and the amplitude-frequency characteristic curve and the phase-frequency characteristic curve of the calibrated temperature sensor are drawn according to the response characteristic curve; Step three: the rotating speed of the rotating disc of the rotating disc type sine temperature generator is changed, and the response characteristic curves of the standard temperature sensor and the calibrated temperature sensor at the corresponding frequency of the rotating speed are collected, and the amplitude-frequency characteristic curves and the phase-frequency characteristic curves of the standard temperature sensor and the calibrated temperature sensor are drawn according to the response characteristic curves; the amplitude-frequency characteristic and the phase-frequency characteristic of the air flow temperature sensor are analyzed under the air flow temperature changing according to the sine rule, and the dynamic characteristic calibration of the air flow temperature under the sine temperature excitation is realized.

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