A thin film platinum resistance dynamic total temperature probe for measuring wide flow range between turbine stages

Abstract

The present application belongs to the technical field of dynamic temperature test, and particularly relates to a turbine interstage wide airflow range thin film platinum resistance dynamic total temperature probe, which comprises a probe support rod, a probe head, a temperature sensing surface, a bottom thin film thermal resistance, a top thin film thermal resistance, a positioning block, a lead hole and a circular pipeline. The probe support rod is provided with the positioning block at the bottom, and is integrated with the probe head. The bottom thin film platinum resistance and the top thin film platinum resistance are arranged on the temperature sensing surface along the probe axis. The leads of the bottom thin film platinum resistance and the top thin film platinum resistance are led out through the circular pipeline after passing through the lead hole. The present application reduces the interference of the dynamic temperature probe on the measured flow field in the high Mach number range through the innovative probe head structure design, effectively expands the angle measurement range of the probe, and greatly improves the high-precision measurement of the narrow space between the turbine stages in the wide Mach number range through the calibration and measurement data processing method, so that the accurate measurement of the wide airflow angle range between the turbine stages is realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of dynamic temperature measurement, and particularly relates to a thin-film platinum resistance dynamic total temperature probe for measuring a wide airflow range between turbine stages, which is suitable for measuring the transient temperature field under the condition of a wide airflow range between engine turbine stages, and the core is to quickly and accurately measure the transient temperature change between engine turbine stages. BACKGROUND

[0002] With the pursuit of high performance of modern engines, most turbine blades are designed in a curved swept shape, and the blade curvature changes greatly, which means that the angle of airflow will also change greatly after passing through the trailing edge of the blade, and the angle difference is greater in different blade height directions, which can reach a range of ±60° or higher. In order to obtain the performance parameters of the turbine components in the engine and the internal flow field structure, it is necessary to measure the dynamic temperature between the stages. The conventional dynamic temperature probe is not sensitive to the airflow angle, and it is difficult to meet the measurement requirements in the complex internal flow environment between the turbine stages. Although the displacement mechanism can measure the flow field structure with large changes in airflow angle by clamping the dynamic temperature probe to rotate at different blade height positions, it is difficult to install the displacement mechanism on some small and compact turbine testers. In addition, rotating to cover the measurement range of a wide airflow angle will greatly increase the test time and introduce many unnecessary test errors.

[0003] The commonly used measurement method in current engineering applications is a small-inertia thermocouple probe. The main means to improve the dynamic frequency response characteristic is to reduce the diameter of the measuring wire and the size of the thermal junction, and to perform computer dynamic compensation and correction of various temperature measurement errors. For the current dynamic temperature test requirements of the engine, the dynamic performance of the small-inertia thermocouple is still unable to meet the requirements. If the wire diameter is simply reduced to improve the frequency response characteristic, the reliability of the thermocouple will be greatly reduced, and the engineering application feasibility is lacking. In addition, the large size of the probe will also cause serious disturbance to the measured flow field environment, affecting the accuracy of the measurement. With the continuous optimization of turbine components, the internal airflow velocity is continuously improved, and the velocity can reach high subsonic or even supersonic. The measured flow field has a very wide Mach number range, and the destruction of the probe to the flow field itself will be more serious, which also brings greater challenges to the aerodynamic design, geometric size and structural design of the probe.

[0004] Therefore, it is urgent to develop a dynamic total temperature probe that is fast, high-precision, resistant to airflow scouring, has little disturbance to the flow field, and is suitable for wide airflow range between turbine stages, in order to realize accurate measurement of the dynamic temperature of the unsteady flow field between the turbine stages, and provide reliable measurement means and technical support for high-performance turbine design and optimization. SUMMARY

[0005] A kind of thin film platinum resistance dynamic total temperature probe for measuring wide airflow range between turbine stages, comprising probe support, probe head, temperature sensing surface, bottom thin film platinum resistance, top thin film platinum resistance, positioning block, lead hole, circular pipe.Probe support has positioning block at bottom, probe support is integrated with probe head, bottom thin film platinum resistance and top thin film platinum resistance are installed on temperature sensing surface and arranged along probe axis, bottom thin film platinum resistance lead and top thin film platinum resistance lead are led out through circular pipe after passing through lead hole.

[0006] Wide range calibration is carried out on a kind of thin film platinum resistance dynamic total temperature probe for measuring wide airflow range between turbine stages in calibration wind tunnel, calibration speed range is 0.1 Mach to 1.4 Mach, deflection angle range is-80 ° to 80 °, pitch angle range is-40 ° to 40 °, when wind tunnel test calibration, temperature measurement is carried out simultaneously by using two thin film platinum resistances, two thin film platinum resistances are provided with different constant currents by using signal generator, two resistances have different initial temperatures, but have same convective heat transfer surface heat transfer coefficient h, so that heat flux density ratio of two thin film platinum resistances under different working conditions is obtained, heat flux density ratio is defined as A, and following equation is satisfied:

[0007] q1=h (T t -T w1 )

[0008] q2=h (T t -T w2 )

[0009]

[0010] In the formula, q1, q2-heat flux density of thin film platinum resistance, unit W / m 2 ; Tw1, Tw2-temperature measured by thin film platinum resistance, unit K; Tt-total temperature of calibration wind tunnel flow, unit K, heat flux density ratio A under different calibration working conditions can be obtained by above-mentioned calibration method;

[0011] When test measurement, corresponding heat flux density ratio A can be found from calibration data under known flow working condition, total temperature T g of measured airflow is calculated by following formula from measured Tw1, Tw2 data:

[0012]

[0013] The application provides a kind of thin film platinum resistance dynamic total temperature probe for measuring wide airflow range between turbine stages, and the technical problems to be solved are: first, the precision problem of existing dynamic temperature probe is solved.Second, the problem that existing dynamic temperature probe is limited to the low frequency response of traditional dynamic temperature sensor is solved.Third, the problem that existing dynamic temperature probe has large interference to flow field is solved.

[0014] The technical solution of the present application is:

[0015] 1. A thin-film platinum resistance dynamic total temperature probe for measuring wide air flow range between turbine stages, comprising a probe stem (1), a probe head (2), a temperature sensing surface (3), a bottom thin-film platinum resistance (4), a top thin-film platinum resistance (5), a positioning block (6), a lead hole (7), and a circular duct (8), characterized in that the probe stem (1) has the positioning block (6) at the bottom, the probe stem (1) is integrated with the probe head (2), the bottom thin-film platinum resistance (4) and the top thin-film platinum resistance (5) are installed on the temperature sensing surface (3) and arranged along the probe axis, and the lead (9) of the bottom thin-film platinum resistance and the lead (10) of the top thin-film platinum resistance are led out through the circular duct (8) after passing through the lead hole (7).

[0016] 2. The probe stem (1) is a cylinder, and the cross-sectional diameter d of the probe stem (1) is in the range of 8 mm≤d≤20 mm.

[0017] 3. The cross section of the positioning block (6) is a regular quadrilateral, and the cross section shape can be selected as a regular pentagon, a regular hexagon, or a regular heptagon. The thickness of the positioning block is a, and a is in the range of 2 mm≤a≤10 mm. The distance from the positioning block (6) to the bottom of the probe stem (1) is b, and b is in the range of 5 mm≤b≤20 mm.

[0018] 4. The probe head (2) is integrated with the probe stem, and the head is in the shape of a circular arc, or can be in the shape of a cone or a circular truncated cone. The probe head is made of an insulating and heat-insulating material to reduce the heat conduction error during measurement, and to improve the measurement accuracy and frequency response of the probe.

[0019] 5. The temperature sensing surface (3) is in the shape of an ellipsoidal recess, or can be in the shape of a spherical recess. The distance from the center of the recess to the top of the probe is u, and u is in the range of 10 mm≤u≤20 mm. The depth of the recess is h, and h is in the range of 2 mm≤h≤5 mm. The projection of the temperature sensing surface (3) along the vertical direction of the probe stem axis is parallel to the plane of the positioning block.

[0020] 6. Two lead holes (7) are formed on the temperature sensing surface (3) along the axis. The two lead holes are equal in size. The diameter of the lead hole is b, and b is in the range of 0.2 mm≤b≤1 mm. The distance between the centers of the two lead holes is x, and x is in the range of 0.5 mm≤x≤1.5 mm.

[0021] 7. The bottom thin-film platinum resistance (4) and the top thin-film platinum resistance (5) are installed on the lead hole (7). The bottom thin-film platinum resistance (4) and the top thin-film platinum resistance (5) are made of the same material and have the same size. Both the bottom thin-film platinum resistance (4) and the top thin-film platinum resistance (5) are micro four-wire thin-film platinum resistances, with a length of 0.5 mm to 3 mm, a width of 0.1 mm to 1.5 mm, and a thickness of 0.01 mm to 0.2 mm.

[0022] 8. The probe stem (1) is internally provided with a circular channel (8) along the axial direction, the diameter of the circular channel is a, and the value range of a is 5mm≤a≤15mm, the lead wire (9) of the bottom thin-film platinum resistance and the lead wire (10) of the top thin-film platinum resistance are led out through the lead wire hole (7) and the circular channel (8) and connected with external collection equipment.

[0023] The thin-film platinum resistance dynamic total temperature probe for measuring a wide airflow range between turbine stages has the following beneficial effects:

[0024] Beneficial effect one: the probe head structure design of the present application reduces the interference of the dynamic temperature probe on the measured flow field in a high Mach number range, effectively expands the airflow insensitive angle range of the probe, and realizes the measurement in a wide airflow angle range between turbine stages.

[0025] Beneficial effect two: based on the design of the double thin-film platinum resistance, the two thin-film platinum resistances compensate each other during temperature measurement and calibration technology, which greatly improves the measurement accuracy of the dynamic total temperature and ensures the accurate and reliable response of the thin-film platinum resistance at different temperature points.

[0026] Beneficial effect three: the probe head structure of the present application is simple and compact, which is an "I" type, small in size, and the double thin-film platinum resistances are vertically arranged, which improves the spatial resolution of the probe and facilitates the insertion into the narrow space between turbine stages for testing.

[0027] Beneficial effect four: the probe of the present application has a positioning function, the positioning block forms a positioning reference, the installation of the probe is convenient and simple, and the probe does not need to be rotated during measurement, which has no periodic requirement on the measured flow field and has a wide application range.

[0028] Beneficial effect five: the top end profile of the probe head of the present application adopts a curve design, has good airflow fitting property, and the boundary layer is not easy to separate, which has little influence on the measurement data of the top sensing part.

[0029] Beneficial effect six: the calibration and measurement data processing method of the present application can greatly improve the measurement accuracy of the dynamic total temperature between turbine stages, and only the inflow parameters need to be obtained during measurement, without the need to understand the physical parameters of the measured medium. DETAILED DESCRIPTION

[0030] Figure 1 is a structure schematic view of a thin-film platinum resistance dynamic total temperature probe for measuring a wide airflow range between turbine stages in the embodiment of the present application.

[0031] Figure 2 is Figure 1 a top view of

[0032] Figure 3 is Figure 1 a side view of

[0033] Figure 4 is Figure 1 a B sectional view of the figure.

[0034] Figure 5 is Figure 1 a A sectional view and a partial enlarged view of the figure.

[0035] Wherein: 1-probe strut, 2-probe head, 3-temperature sensing surface, 4-bottom thin film platinum resistance, 5-top thin film platinum resistance, 6-positioning block, 7-lead hole, 8-circular duct, 9-lead of bottom thin film platinum resistance, 10-lead of top thin film platinum resistance. DETAILED DESCRIPTION

[0036] The present application will be described in detail below with reference to the accompanying drawings and specific implementation cases, so that the advantages and features of the present application can be more easily understood by those skilled in the art, and the protection scope of the present application can be more clearly and explicitly defined.

[0037] As Figures 1 to 5 shown is a kind of double thin film platinum resistance dynamic total temperature probe for measuring wide airflow range between turbine stages, which is composed of probe strut (1), probe head (2), temperature sensing surface (3), bottom thin film platinum resistance (4), top thin film platinum resistance (5), positioning block (6), lead hole (7) and circular duct (8), and is characterized by that: the probe strut (1) has positioning block (6) at the bottom, the probe strut (1) is integrated with the probe head (2), the bottom thin film platinum resistance (4) and the top thin film platinum resistance (5) are installed on the temperature sensing surface (3) and arranged along the probe axis, and the lead (9) of bottom thin film platinum resistance and the lead (10) of top thin film platinum resistance are led out through the circular duct (8) after passing through the lead hole (7).

[0038] The probe strut (1) is a cylinder, and the cross-sectional diameter d of the probe strut (1) is 10 mm.

[0039] The positioning block (6) has a square cross section, and the thickness of the positioning block (6) is a, and the value of a is 5 mm; the distance between the positioning block (6) and the bottom of the probe strut (1) is b, and the value of b is 15 mm.

[0040] The probe head (2) is integrated with the probe strut, and the head is arc-shaped; the probe head is made of insulating and heat-insulating material, so as to reduce the heat conduction error during measurement, improve the measurement accuracy and frequency response of the probe.

[0041] The temperature sensing surface (3) is an ellipsoidal recess, the distance between the center of the recess and the top of the probe is u, and the value of u is 15 mm; the depth of the recess is h, and the value of h is 2 mm; the projection of the temperature sensing surface (3) along the vertical probe strut axis direction is parallel to the plane of the positioning block.

[0042] The temperature sensing surface (3) has two lead holes (7) along the axis, the two lead holes are equal in size, the diameter of the lead hole is b, the value of b is 0.5mm; the distance between the centers is x, the value of x is 0.5mm.

[0043] The bottom thin film platinum resistance (4) and the top thin film platinum resistance (5) are installed on the lead hole (7), the bottom thin film platinum resistance (4) and the top thin film platinum resistance (5) are the same in material and size, the bottom thin film platinum resistance (4) and the top thin film platinum resistance (5) are micro four-wire thin film platinum resistances, the length is 1mm, the width is 0.5mm, and the thickness is 0.1mm.

[0044] The probe support rod (1) has a circular pipeline (8) inside along the axis, the diameter of the circular pipeline is a, the value of a is 5mm, the lead wire (9) of the bottom thin film platinum resistance and the lead wire (10) of the top thin film platinum resistance are led out through the circular pipeline (8) after passing through the lead hole (7) and connected with external collection equipment.

[0045] The double thin film platinum resistance dynamic total temperature probe for measuring wide air flow range between turbine stages introduced in the embodiment of the application is used to calibrate a thin film platinum resistance dynamic total temperature probe for measuring wide air flow range between turbine stages in a calibration wind tunnel, the calibration speed range is 0.1 Mach to 1.4 Mach with an interval of 0.1 Mach, the deflection angle range is -80° to 80° with an interval of 5°, the pitch angle range is -40° to 40° with an interval of 5°, when the wind tunnel test calibration is performed, two thin film platinum resistances are used to simultaneously measure the temperature, the two thin film platinum resistances are provided with different constant currents by a signal generator, the two resistances have different initial temperatures but have the same convective heat transfer surface heat transfer coefficient h, so that the heat flux density ratio of the two thin film platinum resistances under different working conditions is obtained, the heat flux density ratio is defined as A and satisfies the following equation:

[0046] q1=h(T t -T w1 )

[0047] q2=h(T t -T w2 )

[0048]

[0049] In the formula, q1 and q2 are the heat flux densities of the thin film platinum resistances, the unit is W / m 2 ; Tw1 and Tw2 are the temperatures measured by the thin film platinum resistances, the unit is K; Tt is the total temperature of the flow in the calibration wind tunnel, the unit is K, the heat flux density ratio A under different calibration working conditions can be obtained through the above calibration method.

[0050] During the test measurement, under the known inflow condition, the corresponding heat flux ratio A can be found from the calibration data, and the total temperature of the measured gas flow T is calculated from the measured Tw1, Tw2 data through the following formula g :

[0051]

Claims

1. A data processing method based on measuring the turbine inter-stage wide flow range of thin-film platinum resistance dynamic total temperature probe, the probe includes probe support rod (1), probe head (2), temperature sensing surface (3), bottom thin-film platinum resistance (4), top thin-film platinum resistance (5), positioning block (6), lead hole (7), round pipe (8) is composed, it is characterized by: The probe stem (1) has a positioning block (6) at the bottom, the probe stem (1) is integrated with the probe head (2), the bottom thin film platinum resistance (4) and the top thin film platinum resistance (5) are installed on the temperature sensing surface (3) and arranged along the probe axis, the lead wire (9) of the bottom thin film platinum resistance and the lead wire (10) of the top thin film platinum resistance are led out through the lead wire hole (7) and then through the circular pipe (8); The probe stem (1) is a cylinder, the cross-sectional diameter d of the probe stem (1) is 8mm≤d≤20mm; The positioning block (6) has a cross section of a regular quadrilateral, a regular pentagon, a regular hexagon or a regular heptagon, the thickness of the positioning block (6) is a, the value range of a is 2mm≤a≤10mm, the distance from the positioning block (6) to the bottom of the probe stem (1) is b, the value range of b is 5mm≤b≤20mm; The probe head (2) is integrated with the probe stem, the head is arc-shaped, conical or circular truncated cone-shaped, the probe head (2) is made of insulating and heat insulating material, so as to reduce the heat conduction error during measurement, improve the measurement accuracy and frequency response of the probe; The temperature sensing surface (3) is an ellipsoidal groove or a spherical groove, the distance from the center of the groove to the top of the probe is u, the value range of u is 10mm≤u≤20mm, the depth of the groove is h, the value range of h is 2mm≤h≤5mm, and the projection of the temperature sensing surface (3) along the vertical probe stem axis direction is parallel to the plane of the positioning block; The temperature sensing surface (3) has two lead wire holes (7) along the axis, the two lead wire holes are equal in size, the diameter of the lead wire hole is b, the value range of b is 0.2mm≤b≤1mm, the distance between the centers of the two lead wire holes is x, the value range of x is 0.5mm≤x≤1.5mm; The bottom thin film platinum resistance (4) and the top thin film platinum resistance (5) are installed on the lead wire hole (7) respectively, the bottom thin film platinum resistance (4) and the top thin film platinum resistance (5) are made of the same material and have the same size, the bottom thin film platinum resistance (4) and the top thin film platinum resistance (5) are both micro four-wire thin film platinum resistances, the length is 0.5mm to 3mm, the width is 0.1mm to 1.5mm, and the thickness is 0.01mm to 0.2mm; The probe stem (1) has a circular pipe (8) inside along the axial direction, the diameter of the circular pipe is a, the value range of a is 5mm≤a≤15mm, the lead wire (9) of the bottom thin film platinum resistance and the lead wire (10) of the top thin film platinum resistance are led out through the circular pipe (8) after passing through the lead wire hole (7) and connected with the external collection equipment; A thin film platinum resistance dynamic total temperature probe for measuring a wide range of turbine inter-stage wide flow is calibrated in a calibration wind tunnel, the calibration speed range is 0.1 Mach to 1.4 Mach, the deflection angle range is-80° to 80°, and the pitch angle range is-40° to 40°, when the wind tunnel test is calibrated, two pieces of thin film platinum resistance are used to measure the temperature at the same time, the two pieces of thin film platinum resistance are provided with different constant currents by a signal generator, the initial temperatures of the two pieces of resistance are different, but they have the same convective heat transfer surface heat transfer coefficient h, so that the heat flux density ratio of the two pieces of thin film platinum resistance under different working conditions is obtained, the heat flux density ratio is defined as A, and the following equation is satisfied: q1 = h(T t - T w1 ) q2 = h(T t - T w2 ) In the formula, q1, q2 are heat flux densities of the thin-film platinum resistance, in units of W / m 2 ; Tw1, Tw2 are temperatures measured by the thin-film platinum resistance, in units of K; Tt is the total temperature of the incoming flow of the calibration wind tunnel, in units of K, and the ratio A of the heat flux densities under different calibration conditions can be obtained through the above calibration method. During the test measurement, under the known flow conditions, the corresponding heat flux ratio A can be found from the calibration data, and the total temperature of the measured gas flow T is calculated from the measured Tw1, Tw2 data through the following formula g : The method only needs to obtain the flow parameters and does not need to understand the physical parameters of the measured medium.

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