A method for measuring total pressure at the inlet and outlet of a low-pressure turbine of an aero-engine

Abstract

The application belongs to the technical field of turbine inlet and outlet total pressure measurement of an aero-engine, and particularly relates to a turbine inlet and outlet total pressure measurement method of an aero-engine. The method considers that the wake flow affected by the rectification blade cannot be mixed uniformly at the inlet total pressure measurement section, and the wake flow affected by the guide blade cannot be mixed uniformly at the outlet total pressure measurement section, and arranges the inlet total pressure measurement probe and the outlet total pressure measurement probe. In addition, the method considers that the total pressure is periodically distributed about the rectification blade at the inlet total pressure measurement section, and the total pressure is periodically distributed about the guide blade at the outlet total pressure measurement section, arranges the total pressure measured by each branch inlet total pressure measurement probe and outlet total pressure measurement probe in one period, and then extends to the whole period, so that the total pressure distribution of the inlet and outlet total pressure measurement sections is obtained, and the method has high measurement accuracy.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of turbine inlet and outlet total pressure measurement of an aero-engine, and particularly relates to a turbine inlet and outlet total pressure measurement method of a low-pressure turbine of an aero-engine. BACKGROUND

[0002] The expansion ratio of the low-pressure turbine of the aero-engine is calculated by measuring the inlet and outlet total pressures of the low-pressure turbine.

[0003] The guide vanes and the moving vanes are arranged in sequence in the low-pressure turbine of the aero-engine. Considering that the inlet of the low-pressure turbine guide vane is generally non-axial inlet, in order to provide the inlet flow angle of the guide vane, the fairing vane is additionally arranged before the guide vane, such as Figure 1 , wherein the cross section 1-1 between the fairing vane and the guide vane is the inlet total pressure measurement section, and the cross section 2-2 after the moving vane is the outlet total pressure measurement section.

[0004] Currently, when measuring the inlet and outlet total pressures of the low-pressure turbine, the total pressure probes are generally arranged on the inlet total pressure measurement section and the outlet total pressure measurement section. For example, in a specific example, four total pressure probes are arranged on the inlet total pressure measurement section and the outlet total pressure measurement section respectively to measure the total pressure, and the angles of the four total pressure probes in the circumferential direction are 0°, 90°, 180° and 270°, as shown in Figure 2 .

[0005] In practice, the main flow and the wake flow exist in the low-pressure turbine. The main flow and the wake flow affected by the fairing vane cannot be uniformly mixed at the inlet total pressure measurement section, and the main flow and the wake flow affected by the guide vane cannot be uniformly mixed at the outlet total pressure measurement section. When the total pressure probes are arranged on the inlet total pressure measurement section and the outlet total pressure measurement section in the circumferential direction, the total pressure probes are likely to be all in the main flow or all in the wake flow, and the measured total pressure cannot accurately reflect the total pressure distribution of the inlet total pressure measurement section and the outlet total pressure measurement section, so that the expansion ratio of the low-pressure turbine cannot be accurately obtained.

[0006] For example, in a specific implementation, the number of the fairing vanes of the low-pressure turbine is 60, the number of the guide vanes is 40, and the number of the moving vanes is 81. At the 50% blade height under the design point speed, the S1 flow surface flow velocity calculation distribution is as shown in Figure 3 . It can be seen from Figure 3 that the main flow and the wake flow affected by the fairing vane are not uniformly mixed at the inlet total pressure measurement section, but are periodically distributed about the fairing vane. If the four total pressure probes are arranged on the inlet total pressure measurement section in the circumferential direction, the total pressure probes are likely to be all in the main flow or all in the wake flow affected by the fairing vane, and the measured total pressure cannot accurately reflect the total pressure distribution of the inlet total pressure measurement section. In addition, it can be seen from Figure 3As can be seen, the mainstream airflow and the wake airflow affected by the guide vane are not mixed evenly at the total pressure measurement section at the outlet. Instead, they are periodically distributed about the guide vane. If the four total pressure probes are evenly distributed circumferentially on the total pressure measurement section at the outlet, they are all likely to be in the mainstream airflow or in the wake airflow affected by the guide vane. Therefore, the measured total pressure cannot accurately reflect the total pressure distribution at the total pressure measurement section at the outlet.

[0007] This application is made in view of the aforementioned technical deficiencies.

[0008] It should be noted that the above background information is only used to assist in understanding the inventive concept and technical solution of this invention, and it does not necessarily belong to the prior art of this application. In the absence of clear evidence that the above information was disclosed on the filing date of this application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0009] The purpose of this application is to provide a method for measuring the total pressure at the inlet and outlet of a low-pressure turbine in an aero-engine, so as to overcome or mitigate at least one of the known technical defects.

[0010] The technical solution of this application is:

[0011] A method for measuring the total pressure at the inlet and outlet of a low-pressure turbine in an aero-engine, comprising:

[0012] Draw the circular cross-section for measuring the total pressure at the inlet;

[0013] Mark the circumferential position of the rectifier blades on the inlet total pressure measurement section;

[0014] Divide the circular cross-section of the inlet total pressure measurement into n equal parts, where n is equal to the number of inlet total pressure measurement probes;

[0015] Mark the arc segments between the circumferential positions of the rectifier blades on both sides of the n equally divided points on the circular cross-section of the inlet total pressure measurement section.

[0016] Divide the n arc segments marked on the circular section of the inlet total pressure measurement section into n equal parts. On each arc segment, take the starting end point as the first division point and the ending end point as the (n+1)th division point.

[0017] The circumferential position of the i-th equidistant point of the i-th arc segment on the circular cross-section of the inlet total pressure measurement is selected as the circumferential position of the i-th inlet total pressure measurement probe on the inlet total pressure measurement cross-section, and the total pressure of the inlet cross-section is measured, where i = 1, 2, ..., n;

[0018] Draw the circular cross-section for measuring the total pressure at the outlet;

[0019] Mark the circumferential position of the guide vane on the total pressure measurement section at the outlet;

[0020] Divide the circular section of the outlet total pressure measurement cross-section into m equal parts, where m is equal to the number of outlet total pressure measurement probes;

[0021] Mark the arc segments between the guide vanes on both sides of the m equally divided points on the circular cross-section of the outlet total pressure measurement section;

[0022] Divide the m arc segments marked on the circular section of the outlet total pressure measurement section into m equal parts. On each arc segment, take the starting end point as the first division point and the ending end point as the (m+1)th division point.

[0023] The circumferential position of the jth equidistant point of the jth arc segment on the circular cross-section of the outlet total pressure measurement section is selected as the circumferential position of the jth outlet total pressure measurement probe on the outlet total pressure measurement cross-section, and the total pressure of the outlet cross-section is measured, j = 1, 2...m.

[0024] According to at least one embodiment of this application, the above-described method for measuring the total pressure at the inlet and outlet of a low-pressure turbine in an aero-engine further includes:

[0025] The total pressure measured by each inlet total pressure measuring probe is arranged and combined according to the corresponding equal division points within the circumferential position of the two rectifier blades to obtain the total pressure distribution between the two rectifier blades on the inlet total pressure measuring section. This is periodically extended to the inlet total pressure measuring section to obtain the total pressure distribution of the inlet total pressure measuring section.

[0026] According to at least one embodiment of this application, the above-described method for measuring the total pressure at the inlet and outlet of a low-pressure turbine in an aero-engine further includes:

[0027] The total pressure measured by each outlet total pressure measuring probe is arranged and combined according to the corresponding equal division points within the circumferential position of the two guide vanes to obtain the total pressure distribution between the two guide vanes on the outlet total pressure measuring section. This is periodically extended to the outlet total pressure measuring section to obtain the total pressure distribution of the outlet total pressure measuring section.

[0028] This application has at least the following beneficial technical effects:

[0029] A method for measuring the total pressure at the inlet and outlet of a low-pressure turbine in an aero-engine is provided. Considering the uneven mixing of the mainstream airflow at the inlet total pressure measurement section with the wake airflow affected by the rectifier blades, and the uneven mixing of the mainstream airflow at the outlet total pressure measurement section with the wake airflow affected by the guide vanes, the method arranges the inlet and outlet total pressure measurement probes. Furthermore, considering the periodic distribution of the total pressure at the inlet and outlet total pressure measurement sections with respect to the rectifier blades, and the periodic distribution of the total pressure at the outlet total pressure measurement section with respect to the guide vanes, the total pressure measured by each inlet and outlet total pressure measurement probe is arranged and combined within one cycle, and then extended to the entire cycle, thereby obtaining the total pressure distribution at the inlet and outlet total pressure measurement sections, resulting in high measurement accuracy. Attached Figure Description

[0030] Figure 1 This is a schematic diagram showing the positional distribution of the rectifier blades, guide vanes, and moving blades in the low-pressure turbine of an aero-engine.

[0031] Figure 2 This is a schematic diagram of total pressure measurement performed by circumferentially distributing total pressure probes on the total pressure measurement sections at the inlet and outlet of the low-pressure turbine of an aero-engine.

[0032] Figure 3 This is a schematic diagram showing the calculated velocity distribution of the S1 flow surface at 50% blade height of the low-pressure turbine of an aero-engine at the design point speed.

[0033] Figure 4 This is a flowchart illustrating the method for measuring the total pressure at the inlet and outlet of a low-pressure turbine in an aero-engine, as provided in an embodiment of this application.

[0034] Figure 5 This is a schematic diagram provided in this application embodiment, showing the circumferential position of the rectifier blades marked on the inlet total pressure measurement section and divided equally according to the number of inlet total pressure measurements;

[0035] Figure 6 This is a schematic diagram provided in an embodiment of this application.

[0036] To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. Furthermore, the drawings are for illustrative purposes only and should not be construed as limiting this application. Detailed Implementation

[0037] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings. Other related parts can be referred to the general design. In the absence of conflict, the embodiments and technical features in the embodiments of this application can be combined with each other to obtain new embodiments.

[0038] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0039] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0040] The following is in conjunction with the appendix Figures 1 to 6 This application will be described in further detail.

[0041] A method for measuring the total pressure at the inlet and outlet of a low-pressure turbine in an aero-engine, such as Figure 4 As shown, it includes:

[0042] Draw a circular cross-section for measuring the total pressure at the inlet, the radius of which can be referenced from the radius of the cross-section for measuring the total pressure at the inlet;

[0043] Mark the circumferential position of the rectifier blades on the inlet total pressure measurement section;

[0044] Divide the circular cross-section of the inlet total pressure measurement into n equal parts, where n is equal to the number of inlet total pressure measurement probes;

[0045] Mark the arc segments between the circumferential positions of the rectifier blades on both sides of the n equally divided points on the circular cross-section of the inlet total pressure measurement section.

[0046] Divide the n arc segments marked on the circular section of the inlet total pressure measurement section into n equal parts. On each arc segment, take the starting end point as the first division point and the ending end point as the (n+1)th division point.

[0047] The circumferential position of the i-th equidistant point of the i-th arc segment on the circular inlet total pressure measurement section is selected as the circumferential position of the i-th inlet total pressure measurement probe on the inlet total pressure measurement section. The total pressure of the inlet section is measured, where i = 1, 2...n. This is to fully consider the fact that the mainstream airflow and the wake airflow affected by the rectifier blades at the inlet total pressure measurement section cannot be mixed evenly, so that the distribution of the inlet total pressure measurement probe on the circumferential direction of the inlet total pressure measurement section is more representative, and avoids that all probes are in the mainstream airflow or all probes are in the wake airflow of the rectifier blades.

[0048] The total pressure measured by n inlet total pressure measuring probes is arranged and combined according to the corresponding equal division points within the circumferential position of the two rectifier blades to obtain the total pressure distribution between the two rectifier blades on the inlet total pressure measuring section. This is periodically extended to the inlet total pressure measuring section to obtain the total pressure distribution of the inlet total pressure measuring section, so as to conform to the actual periodic distribution of the total pressure at the inlet total pressure measuring section with respect to the rectifier blades.

[0049] Draw a circular cross-section for measuring the total pressure at the outlet, the radius of which can be referenced from the radius of the cross-section for measuring the total pressure at the outlet;

[0050] Mark the circumferential position of the guide vane on the total pressure measurement section at the outlet;

[0051] Divide the circular section of the outlet total pressure measurement cross-section into m equal parts, where m is equal to the number of outlet total pressure measurement probes;

[0052] Mark the arc segments between the guide vanes on both sides of the m equally divided points on the circular cross-section of the outlet total pressure measurement section;

[0053] Divide the m arc segments marked on the circular section of the outlet total pressure measurement section into m equal parts. On each arc segment, take the starting end point as the first division point and the ending end point as the (m+1)th division point.

[0054] The circumferential position of the jth equidistant point of the jth arc segment on the circular total pressure measurement section of the outlet is selected as the circumferential position of the jth outlet total pressure measurement probe on the outlet total pressure measurement section. Total pressure measurement is performed on the outlet section, j = 1, 2...m. This is to fully consider the fact that the mainstream airflow and the wake airflow affected by the guide vane cannot be mixed evenly at the outlet total pressure measurement section, so that the distribution of the outlet total pressure measurement probe on the circumferential direction of the outlet total pressure measurement section is more representative, and avoids that all of them are in the mainstream airflow or all of them are in the wake airflow of the guide vane.

[0055] The total pressure measured by the m-outlet total pressure measuring probe is arranged and combined according to the corresponding equal division points within the circumferential position of the two guide vanes to obtain the total pressure distribution between the two guide vanes on the outlet total pressure measuring section. This is periodically extended to the outlet total pressure measuring section to obtain the total pressure distribution of the outlet total pressure measuring section, which conforms to the actual periodic distribution of the total pressure with respect to the guide vanes at the outlet total pressure measuring section.

[0056] In a specific example, the number of rectifier blades is 60. Four inlet total pressure measurement probes are arranged circumferentially along the inlet total pressure measurement section to measure the inlet total pressure. The process can be referred to as follows:

[0057] Draw the circular cross-section for measuring the total pressure at the inlet;

[0058] On the inlet total pressure measurement section, mark the circumferential positions of the 60 rectifier blades, such as... Figure 5 As shown;

[0059] Divide the circular cross-section of the inlet total pressure measurement into four equal parts, with the division points being ①, ②, ③, and ④. Figure 5 As shown;

[0060] On the circular cross-section of the inlet total pressure measurement, the two sides of the dividing point ① are the circumferential positions of blade 1 and blade 2. Divide the arc segment 4 between blade 1 and blade 2 into equal parts, as follows: Figure 6 As shown, the first inlet total pressure measuring probe is arranged at the circumferential position corresponding to the first equal division point on the inlet total pressure measuring section.

[0061] On the circular cross-section of the inlet total pressure measurement, the two sides of the dividing point ② are the circumferential positions of blades 16 and 17. Divide the arc segment between blades 16 and 17 into 4 equal parts, as follows: Figure 6 As shown, the second inlet total pressure measuring probe is arranged at the position corresponding to the second division point on the inlet total pressure measuring section;

[0062] On the circular cross-section of the inlet total pressure measurement, the two sides of the dividing point ③ are the circumferential positions of blades 31 and 32. Divide the arc segment between blades 31 and 32 into 4 equal parts, as follows: Figure 6 As shown, the third inlet total pressure measuring probe is arranged at the position corresponding to the third division point on the inlet total pressure measuring section;

[0063] On the circular cross-section of the inlet total pressure measurement, the two sides of the dividing point ④ are the circumferential positions of blades 46 and 47. Divide the arc segment between blades 46 and 47 into 4 equal parts, as follows: Figure 6 As shown, the fourth inlet total pressure measuring probe is arranged at the position corresponding to the fourth division point on the inlet total pressure measuring section;

[0064] Four inlet total pressure measuring probes are used to measure the total pressure at the inlet total pressure measuring section. The total pressure measured by the 1st, 2nd, 3rd, and 4th inlet total pressure measuring probes is arranged and combined according to the corresponding positions of equal division points ①, ②, ③, and ④ within the circumferential position of the two rectifier blades to obtain the total pressure distribution between the two rectifier blades on the inlet total pressure measuring section. This method is periodically extended to the inlet total pressure measuring section to obtain the total pressure distribution of the inlet total pressure measuring section, which has high measurement accuracy.

[0065] For the outlet total pressure measurement section, the arrangement of the outlet total pressure measurement probe and its measurement of total pressure can be carried out by referring to the above process of arranging the inlet total pressure measurement probe circumferentially along the inlet total pressure measurement section and measuring the inlet total pressure. No further detailed explanation will be given here.

[0066] The technical solution of this application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A method for measuring the total pressure at the inlet and outlet of a low-pressure turbine in an aero-engine, characterized in that, include: Draw the circular cross-section for measuring the total pressure at the inlet; Mark the circumferential position of the rectifier blades on the inlet total pressure measurement section; Divide the circular cross-section of the inlet total pressure measurement into n equal parts, where n is equal to the number of inlet total pressure measurement probes; Mark the arc segments between the circumferential positions of the rectifier blades on both sides of the n equally divided points on the circular cross-section of the inlet total pressure measurement section. Divide the n arc segments marked on the circular section of the inlet total pressure measurement section into n equal parts. On each arc segment, take the starting end point as the first division point and the ending end point as the (n+1)th division point. The circumferential position of the i-th equidistant point of the i-th arc segment on the circular cross-section of the inlet total pressure measurement is selected as the circumferential position of the i-th inlet total pressure measurement probe on the inlet total pressure measurement cross-section, and the total pressure of the inlet cross-section is measured, where i = 1, 2, ..., n; Draw the circular cross-section for measuring the total pressure at the outlet; Mark the circumferential position of the guide vane on the total pressure measurement section at the outlet; Divide the circular section of the outlet total pressure measurement cross-section into m equal parts, where m is equal to the number of outlet total pressure measurement probes; Mark the arc segments between the guide vanes on both sides of the m equally divided points on the circular cross-section of the outlet total pressure measurement section; Divide the m arc segments marked on the circular section of the outlet total pressure measurement section into m equal parts. On each arc segment, take the starting end point as the first division point and the ending end point as the (m+1)th division point. The circumferential position of the jth equidistant point of the jth arc segment on the circular cross-section of the outlet total pressure measurement section is selected as the circumferential position of the jth outlet total pressure measurement probe on the outlet total pressure measurement cross-section, and the total pressure of the outlet cross-section is measured, j = 1, 2...m.

2. The method for measuring the total pressure at the inlet and outlet of a low-pressure turbine in an aero-engine according to claim 1, characterized in that, Also includes: The total pressure measured by each inlet total pressure measuring probe is arranged and combined according to the corresponding equal division points within the circumferential position of the two rectifier blades to obtain the total pressure distribution between the two rectifier blades on the inlet total pressure measuring section. This is periodically extended to the inlet total pressure measuring section to obtain the total pressure distribution of the inlet total pressure measuring section.

3. The method for measuring the total pressure at the inlet and outlet of a low-pressure turbine in an aero-engine according to claim 1, characterized in that, Also includes: The total pressure measured by each outlet total pressure measuring probe is arranged and combined according to the corresponding equal division points within the circumferential position of the two guide vanes to obtain the total pressure distribution between the two guide vanes on the outlet total pressure measuring section. This is periodically extended to the outlet total pressure measuring section to obtain the total pressure distribution of the outlet total pressure measuring section.

Images