Film platinum resistor dynamic total temperature probe for measuring wide airflow range between turbine stages

Abstract

The invention belongs to the technical field of dynamic temperature testing, and particularly relates to a thin film platinum resistor dynamic total temperature probe for measuring a turbine interstage wide airflow range, which comprises a probe support rod, a probe head, a temperature sensing surface, a bottom thin film thermal resistor, a top thin film thermal resistor, a positioning block, a lead hole and a circular pipeline. A positioning block is arranged at the bottom of the probe supporting rod, the probe supporting rod and the probe head are integrated, the bottom thin film platinum resistor and the top thin film platinum resistor are installed on the temperature sensing face and arranged along the axis of the probe, and a lead of the bottom thin film platinum resistor and a lead of the top thin film platinum resistor pass through lead holes and then are led out through a round pipeline. Through the innovative probe head structure design, the interference of the dynamic temperature probe on a measured flow field in a high Mach number range is reduced, the angle measurement range of the probe is effectively widened, the calibration and measurement data processing method provided by the invention greatly improves the high-precision measurement of a narrow space between turbine stages in a wide Mach number range, and the measurement accuracy is improved. Accurate measurement in a turbine interstage wide airflow angle range is realized.

Description

Technical Field

[0001] The present invention belongs to the technical field of dynamic temperature testing, and specifically relates to a thin-film platinum resistor dynamic total temperature probe for measuring a wide airflow range between turbine stages. The probe is suitable for the transient temperature field under the conditions of a wide airflow range between engine turbine stages, and its core lies in quickly and accurately measuring the transient temperature changes between engine turbine stages. Background Art

[0002] With the pursuit of high performance in modern engines, most turbine blades adopt a swept-curve design, and the curvature of the blades varies greatly, which means that the angle of the airflow will also change greatly after passing through the first-stage blades. The angle difference is even greater in different blade height directions, and can reach a range of ±60° or higher. In order to obtain the performance parameters of the turbine components in the engine and the flow field structure inside, it is necessary to measure the dynamic temperature between stages. Conventional dynamic temperature probes are not sensitive to airflow angles and are difficult to meet the measurement requirements in complex internal flow environments such as between turbine stages. Although the method of clamping the dynamic temperature probe at different blade height positions by a displacement mechanism can measure the flow field structure with large changes in airflow angle, it is difficult to install a displacement mechanism on some small and compact turbine testers. In addition, covering the measurement range of a wide airflow angle by rotation will double the test time and introduce many unnecessary test errors.

[0003] At present, the commonly used measurement method in engineering applications is mainly small inertia thermocouple probes. The main means to improve the dynamic frequency response characteristics is to reduce the diameter of the measuring wire and the welding size of the hot junction, and to perform computer dynamic compensation on the test signal and correct various temperature measurement errors. For the current dynamic temperature test needs of the engine, the dynamic performance of the small inertia thermocouple still cannot meet its requirements. If the wire diameter is reduced blindly in order to improve the frequency response characteristics, the reliability of the thermocouple will be greatly reduced, and the feasibility of engineering application will be lacking. In addition, the large size of the probe will also cause serious interference to the measured flow field environment and affect the accuracy of the measurement. With the continuous optimization of turbine components, the internal air flow velocity continues to increase, and the speed can reach high subsonic or even supersonic. The measured flow field has a wide range of Mach number changes, and the damage 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, in order to quickly and accurately measure the transient temperature changes between engine turbine stages, it is urgent to develop a dynamic total temperature probe that is fast, high-precision, resistant to airflow scouring, has little interference with the flow field, and is suitable for a wide airflow range between turbine stages. This can achieve accurate measurement of the dynamic temperature of the unsteady flow field between turbine stages and provide reliable measurement means and technical support for high-performance turbine design and optimization. Summary of the invention

[0005] A thin-film platinum resistor dynamic total temperature probe for measuring a wide range of airflow between turbine stages comprises a probe support rod, a probe head, a temperature sensing surface, a bottom thin-film thermal resistor, a top thin-film thermal resistor, a positioning block, a lead hole, and a circular pipe. A positioning block is provided at the bottom of the probe support rod, the probe support rod is integrated with the probe head, the bottom thin-film platinum resistor and the top thin-film platinum resistor are mounted on the temperature sensing surface and arranged along the axis of the probe, and the leads of the bottom thin-film platinum resistor and the top thin-film platinum resistor pass through the lead hole and are led out through the circular pipe.

[0006] In the calibration wind tunnel, a thin-film platinum resistor dynamic total temperature probe for measuring a wide range of airflow between turbine stages is calibrated over a wide range. 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°. During the wind tunnel test calibration, two thin-film platinum resistors are used to measure the temperature simultaneously. The two thin-film thermal resistors are provided with different constant currents by a signal generator. The two resistors have different initial temperatures, but have the same convective heat transfer surface heat transfer coefficient h. The ratio of the heat flux density of the two thin-film platinum resistors under different working conditions can be obtained. The heat flux density ratio is defined as A and satisfies the following equation:

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

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

[0009]

[0010] Where, q1, q2——heat flux density of thin film thermal resistor, unit W / m 2 ; Tw1, Tw2——temperature measured by thin film thermal resistor, unit K; Tt——total temperature of the calibration wind tunnel inflow, unit K. The ratio A of heat flux density under different calibration conditions can be obtained by the above calibration method;

[0011] During the test measurement, when the incoming flow condition is known, the corresponding heat flux ratio A can be found from the calibration data. The total temperature T of the measured airflow can be calculated from the measured Tw1 and Tw2 data by the following formula: g :

[0012]

[0013] The present invention provides a thin-film platinum resistance dynamic total temperature probe for measuring a wide range of airflow between turbine stages. The technical problems to be solved are: first, the problem of insufficient accuracy of existing dynamic temperature probes is solved. Second, the problem that existing dynamic temperature probes are limited by the low frequency response of traditional dynamic temperature sensors is solved. Third, the problem that existing dynamic temperature probes have a large interference with the flow field is solved.

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

[0015] 1. A thin film platinum resistor dynamic total temperature probe for measuring a wide range of airflow between turbine stages, comprising a probe support rod (1), a probe head (2), a temperature sensing surface (3), a bottom thin film platinum resistor (4), a top thin film platinum resistor (5), a positioning block (6), a lead hole (7), and a circular pipe (8), wherein the probe support rod (1) has a positioning block (6) at the bottom, the probe support rod (1) is integrated with the probe head (2), the bottom thin film platinum resistor (4) and the top thin film platinum resistor (5) are mounted on the temperature sensing surface (3) and arranged along the probe axis, and the lead wire (9) of the bottom thin film platinum resistor and the lead wire (10) of the top thin film platinum resistor are led out through the circular pipe (8) after passing through the lead hole (7).

[0016] 2. The probe support rod (1) is a cylinder, and its cross-sectional diameter d 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 a regular pentagon, a regular hexagon or a regular heptagon. The thickness of the positioning block is a, and the value range of a is 2 mm ≤ d ≤ 10 mm. The distance between the positioning block (6) and the bottom of the probe support rod (1) is b, and the value range of b is 5 mm ≤ b ≤ 20 mm.

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

[0019] 5. The temperature sensing surface (3) is an ellipsoidal groove, or a spherical groove can be selected. The distance between the center of the groove and the top of the probe is u, and the value range of u is 10 mm ≤ u ≤ 20 mm. The depth of the groove is h, and the value range of h is 2 mm ≤ h ≤ 5 mm. The projection of the temperature sensing surface (3) along the direction perpendicular to the axis of the probe support rod is parallel to the plane of the positioning block.

[0020] 6. Two lead holes (7) are opened along the axis of the temperature sensing surface (3). The two lead holes are of equal size. The diameter of the lead holes is b, and the value range of b is 0.2 mm ≤ y ≤ 1 mm. The center distance of the circle is x, and the value range of x is 0.5 mm ≤ y ≤ 1.5 mm.

[0021] 7. The bottom thin film platinum resistor (4) and the top thin film platinum resistor (5) are installed on the lead hole (7). The bottom thin film platinum resistor (4) and the top thin film platinum resistor (5) are made of the same material and size. The bottom thin film platinum resistor (4) and the top thin film platinum resistor (5) are both miniature four-wire thin film platinum resistors 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. 8. A circular pipe (8) is opened inside the probe support rod (1) along the axial direction. The diameter of the circular pipe is a, and the value range of a is 5 mm ≤ a ≤ 15 mm. The lead wire (9) of the bottom thin film platinum resistor and the lead wire (10) of the top thin film platinum resistor pass through the lead hole (7) and are led out through the circular pipe (8) to be connected to the external collection equipment.

[0022] The present invention provides a double-thin-film platinum resistor dynamic total temperature probe for measuring a wide airflow range between turbine stages, which has the following beneficial effects:

[0023] Beneficial effect 1: The present invention 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. The temperature sensing surface effectively widens the airflow insensitive angular range of the probe, realizing the measurement of a wide airflow angle range between turbine stages.

[0024] Beneficial effect 2: The present invention is based on the design of dual thin film platinum resistors. The two thin film platinum resistors compensate each other and use calibration technology during temperature measurement, which can greatly improve the measurement accuracy of the dynamic total temperature and ensure that the response of the thin film platinum resistor at different temperature points is accurate and reliable.

[0025] Beneficial effect three: The probe head of the present invention has a simple and compact structure, is "I"-shaped, and has a small size. The double thin-film platinum resistor is arranged vertically, which improves the spatial resolution of the probe and can be easily inserted into the narrow space between turbine stages for testing.

[0026] Beneficial effect four: The probe of the present invention has a self-positioning function, the positioning block forms a positioning reference, the probe is easy and convenient to install, does not need to be rotated during measurement, has no periodicity requirement for the measured flow field, and has a wide range of applications.

[0027] Beneficial effect 5: The top profile of the probe head of the present invention adopts a curved design, has good airflow fit, and the boundary layer is not easy to separate, which has little impact on the measurement data of the top sensing part.

[0028] Beneficial Effect 6: The calibration and measurement data processing method of the present invention can greatly improve the measurement accuracy of the dynamic total temperature between turbine stages, and during measurement, only the incoming flow parameters need to be obtained without understanding the physical properties of the measured medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The present invention is a schematic structural diagram of a thin-film platinum resistance dynamic total temperature probe for measuring a wide airflow range between turbine stages in an embodiment of the present invention.

[0030] Figure 2 yes Figure 1 Top view of the .

[0031] Figure 3 yes Figure 1 Side view of.

[0032] Figure 4 yes Figure 1 B-direction cross-sectional view.

[0033] Figure 5 yes Figure 1 A-axis sectional view and partial enlarged view.

[0034] Wherein: 1-probe support rod, 2-probe head, 3-temperature sensing surface, 4-bottom thin film platinum resistor, 5-top thin film platinum resistor, 6-positioning block, 7-lead hole, 8-circular pipe, 9-lead of bottom thin film platinum resistor, 10-top thin film platinum resistor lead. DETAILED DESCRIPTION

[0035] The present invention is described in detail below in conjunction with the accompanying drawings and specific implementation examples so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0036] like Figures 1 to 5 The present invention shows a dual-thin-film platinum resistor dynamic total temperature probe for measuring a wide airflow range between turbine stages, which comprises a probe support rod (1), a probe head (2), a temperature sensing surface (3), a bottom thin-film platinum resistor (4), a top thin-film platinum resistor (5), a positioning block (6), a lead hole (7), and a circular pipe (8). The present invention is characterized in that: a positioning block (6) is provided at the bottom of the probe support rod (1), the probe support rod (1) and the probe head (2) are integrated, the bottom thin-film platinum resistor (4) and the top thin-film platinum resistor (5) are mounted on the temperature sensing surface (3) and arranged along the probe axis, and the lead wire (9) of the bottom thin-film platinum resistor and the lead wire (10) of the top thin-film platinum resistor pass through the lead hole (7) and are then led out through the circular pipe (8).

[0037] The probe support rod (1) is a cylinder, and its cross-sectional diameter d is 10 mm.

[0038] The cross section of the positioning block (6) is a regular quadrilateral, the thickness of the positioning block is a, the value of a is 5 mm, the distance between the positioning block (6) and the bottom of the probe support rod (1) is b, and the value of b is 15 mm.

[0039] The probe head (2) is integrated with the probe support rod and is arc-shaped. The probe head is made of insulating heat-insulating material to reduce the thermal conductivity error during measurement and improve the measurement accuracy and frequency response of the probe.

[0040] The temperature sensing surface (3) is an ellipsoidal groove, the distance between the center of the groove and the top of the probe is u, the value of u is 15 mm, the depth of the groove is h, the value of h is 2 mm; the projection of the temperature sensing surface (3) along the direction perpendicular to the axis of the probe support rod is parallel to the plane of the positioning block.

[0041] Two lead holes (7) are opened along the axis of the temperature sensing surface (3). The two lead holes are of equal size. The diameter of the lead holes is b, and the value of b is 0.5 mm. The center distance is x, and the value of x is 0.5 mm.

[0042] The bottom thin-film platinum resistor (4) and the top thin-film platinum resistor (5) are installed on the lead hole (7). The bottom thin-film platinum resistor (4) and the top thin-film platinum resistor (5) are made of the same material and size. The bottom thin-film platinum resistor (4) and the top thin-film platinum resistor (5) are both miniature four-wire thin-film platinum resistors with a length of 1 mm, a width of 0.5 mm, and a thickness of 0.1 mm.

[0043] A circular pipe (8) is opened inside the probe support rod (1) along the axial direction, and the diameter of the circular pipe is a, and the value of a is 5 mm. The lead wire (9) of the bottom thin film platinum resistor and the lead wire (10) of the top thin film platinum resistor pass through the lead hole (7) and then are led out through the circular pipe (8) to be connected to the external collection equipment.

[0044] A dual-thin-film platinum resistor dynamic total temperature probe for measuring a wide range of airflow between turbine stages introduced in an embodiment of the present invention is calibrated over a wide range in a calibration wind tunnel. The calibration speed range is 0.1 Mach to 1.4 Mach, with an interval of 0.1 Mach, a deflection angle range is -80° to 80°, with an interval of 5°, and a pitch angle range is -40° to 40°, with an interval of 5°. During the wind tunnel test calibration, two thin-film platinum resistors are used to measure the temperature simultaneously. The two thin-film thermal resistors are provided with different constant currents by a signal generator. The two resistors have different initial temperatures, but have the same convective heat transfer surface heat transfer coefficient h. The ratio of the heat flux densities of the two thin-film platinum resistors under different working conditions can be obtained. The ratio of the heat flux densities is defined as A, and the following equation is satisfied:

[0045] q1=h(T t -T w1 )

[0046] q2=h(T t -T w2 )

[0047]

[0048] Where, q1, q2——heat flux density of thin film thermal resistor, unit W / m 2; Tw1, Tw2——temperature measured by thin film thermal resistor, unit K; Tt——total temperature of the calibration wind tunnel inflow, unit K. The ratio A of heat flux density under different calibration conditions can be obtained by the above calibration method;

[0049] During the test measurement, when the incoming flow condition is known, the corresponding heat flux ratio A can be found from the calibration data. The total temperature T of the measured airflow can be calculated from the measured Tw1 and Tw2 data by the following formula: g :

[0050]

Claims

1. A thin film platinum resistor dynamic total temperature probe for measuring a wide range of airflow between turbine stages, comprising a probe support rod (1), a probe head (2), a temperature sensing surface (3), a bottom thin film platinum resistor (4), a top thin film platinum resistor (5), a positioning block (6), a lead hole (7), and a circular pipe (8), characterized in that: A positioning block (6) is provided at the bottom of the probe support rod (1), the probe support rod (1) is integrated with the probe head (2), a bottom thin-film platinum resistor (4) and a top thin-film platinum resistor (5) are mounted on the temperature sensing surface (3) and arranged along the axis of the probe, and a lead wire (9) of the bottom thin-film platinum resistor and a lead wire (10) of the top thin-film platinum resistor are led out through a lead wire hole (7) and a circular pipe (8); The probe support rod (1) is a cylinder, and its cross-sectional diameter d is in the range of 8 mm ≤ d ≤ 20 mm; The cross section of the positioning block (6) is a regular quadrilateral, and the cross section shape can be a regular pentagon, a regular hexagon or a regular heptagon. The thickness of the positioning block is a, and the value range of a is 2 mm ≤ d ≤ 10 mm. The distance between the positioning block (6) and the bottom of the probe support rod (1) is b, and the value range of b is 5 mm ≤ b ≤ 20 mm. The probe head (2) is integrated with the probe support rod, and the head is in an arc shape, or can be in a conical or truncated cone shape. The probe head (2) is made of insulating and heat-insulating material to reduce the thermal conductivity error during measurement and improve the measurement accuracy and frequency response of the probe. The temperature sensing surface (3) is an ellipsoidal groove, or a spherical groove can be selected. The distance between the center of the groove and the top of the probe is u, and the value range of u is 10 mm ≤ u ≤ 20 mm. The depth of the groove is h, and the value range of h is 2 mm ≤ h ≤ 5 mm. The projection of the temperature sensing surface (3) along the direction perpendicular to the axis of the probe support rod is parallel to the plane of the positioning block. Two lead holes (7) are opened along the axis of the temperature sensing surface (3), the two lead holes are equal in size, the diameter of the lead holes is b, and the value range of b is 0.2 mm≤y≤1 mm; the center distance is x, and the value range of x is 0.5 mm≤y≤1.5 mm; The bottom thin-film platinum resistor (4) and the top thin-film platinum resistor (5) are installed on the lead hole (7). The bottom thin-film platinum resistor (4) and the top thin-film platinum resistor (5) are made of the same material and size. The bottom thin-film platinum resistor (4) and the top thin-film platinum resistor (5) are both miniature four-wire thin-film platinum resistors 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. A circular pipe (8) is opened inside the probe support rod (1) along the axial direction, the diameter of the circular pipe is a, and the value range of a is 5 mm≤a≤15 mm. The lead wire (9) of the bottom thin film platinum resistor and the lead wire (10) of the top thin film platinum resistor pass through the lead hole (7) and then are led out through the circular pipe (8) to be connected to an external collection device; The present invention proposes a calibration and measurement data processing method based on a thin film platinum resistor dynamic total temperature probe for measuring a wide airflow range between turbine stages. In a calibration wind tunnel, a thin film platinum resistor dynamic total temperature probe for measuring a wide airflow range between turbine stages is calibrated over a wide range, 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°. During the wind tunnel test calibration, two thin film platinum resistors are used to measure the temperature simultaneously. The two thin film thermal resistors are provided with different constant currents by a signal generator. The two resistors have different initial temperatures but have the same convective heat transfer surface heat transfer coefficient h. The heat flux density ratio of the two thin film platinum resistors under different working conditions can be obtained. The heat flux density ratio is defined as A and satisfies the following equation: q1=h(T t -T w1 ) q2=h(T t -T w2 ) Where, q1, q2——heat flux density of thin film thermal resistor, unit W / m 2 ; Tw1, Tw2——temperature measured by thin film thermal resistor, unit K; Tt——total temperature of the calibration wind tunnel inflow, unit K. The ratio A of heat flux density under different calibration conditions can be obtained by the above calibration method; During the test measurement, when the incoming flow condition is known, the corresponding heat flux ratio A can be found from the calibration data. The total temperature T of the measured airflow can be calculated from the measured Tw1 and Tw2 data by the following formula: g : The dynamic total temperature probe and calibration and measurement data processing method of the present invention can greatly improve the measurement accuracy of the dynamic total temperature between turbine stages, and during measurement, only the incoming flow parameters need to be obtained without understanding the physical property parameters of the measured medium.

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