A method for measuring transient flow in an aeroengine test flow passage

Abstract

The application belongs to the technical field of transient flow measurement in an aero-engine test flow channel, and particularly relates to a transient flow measurement method in an aero-engine test flow channel, a plurality of transient conversion flow measurement instruments are arranged in a circumferential direction on a measurement section of the flow channel, a branch rod of each transient conversion flow measurement instrument extends into the flow channel, a plurality of measurement stacks are arranged in a radial direction, and a total pressure measurement point is arranged at a front edge of a section where each measurement stack is located, static pressure measurement points are arranged on both sides, and then the transient flow is calculated based on measurement values of the measurement points, so that the response requirement of transient flow change can be met, and the static pressure uneven characteristic can be accurately captured.

Description

Technical Field

[0001] This application belongs to the field of transient flow measurement technology in the test flow channel of aero-engines, and specifically relates to a method for measuring transient flow in the test flow channel of aero-engines. Background Technology

[0002] Currently, during aero-engine testing, orifice plates, venturi tube differential pressure flow measurement devices, and double-twisted venturi tube flow measurement devices are mainly used to measure the flow rate within the flow channel. Figure 1 As shown, however, these flow measurement devices are all based on steady-state flow measurement design. They cannot meet the response requirements for dynamic transient flow changes in the flow channel, cannot accurately capture static pressure non-uniformity characteristics, and are difficult to accurately evaluate key parameters in the development process of aero-engines, which makes the development process prone to repetition and prolongs the development cycle.

[0003] This application is made in view of the aforementioned technical deficiencies.

[0004] It should be noted that the above background information is only used to assist in understanding the inventive concept and technical solution of this application, and it does not necessarily belong to the prior art of this patent 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

[0005] The purpose of this application is to provide a method for measuring transient flow rate in the test flow channel of an aero-engine, so as to overcome or mitigate at least one of the known technical defects.

[0006] The technical solution of this application is:

[0007] A method for measuring transient flow rate in a test flow channel of an aero-engine, comprising:

[0008] On the measuring section of the flow channel (1), multiple transient conversion flow measuring instruments (2) are arranged circumferentially, wherein:

[0009] The support rod (3) of each transient conversion flow measurement instrument (2) extends into the flow channel (1), and multiple measurement stacks (4) are arranged radially;

[0010] Each measuring stack (4) has a total pressure measuring point (A) facing the direction of the incoming flow of the flow channel (1) at the front edge of the cross section, and static pressure measuring points (B) perpendicular to the direction of the airflow in the flow channel (1) are set on both sides.

[0011] Calculate the transient flow rate within flow channel (1):

[0012]

[0013] in,

[0014] W represents the transient flow rate within channel (1);

[0015] K W The flow coefficient within the flow channel (1);

[0016] m is the gas dynamics coefficient inside the flow channel (1);

[0017] A e The effective flow area of ​​the flow channel (1);

[0018] γ is the specific heat ratio of the airflow in channel (1);

[0019] R is the gas constant;

[0020] P t The average total pressure of the airflow in the flow channel (1) is measured at each total pressure measuring point (A);

[0021] P s The average static pressure of the airflow in the flow channel (1) is measured at each static pressure measuring point (B).

[0022] According to at least one embodiment of this application, in the above-described transient flow measurement method for an aero-engine test duct, K W The value is obtained by measuring the inner surface layer of the flow channel (1).

[0023] According to at least one embodiment of this application, in the above-described transient flow measurement method for an aero-engine test flow channel,

[0024] According to at least one embodiment of this application, in the above-described transient flow measurement method for an aero-engine test channel, A e The value is equal to the cross-sectional area of ​​the flow channel (1) minus the windward area of ​​each support rod (3).

[0025] This application has at least the following beneficial technical effects:

[0026] A method for measuring transient flow rate in a test flow channel of an aero-engine is provided. The method involves circumferentially arranging multiple transient equivalent flow rate measuring instruments on the measurement cross-section of the flow channel. The support rod of each transient equivalent flow rate measuring instrument extends into the flow channel. Multiple measurement stacks are arranged radially, and a total pressure measuring point is designed at the leading edge of the cross-section where each measurement stack is located. Static pressure measuring points are set on both sides. The transient flow rate is then calculated based on the measured values ​​from each measuring point. This method can meet the response requirements for transient flow rate changes and accurately capture the characteristics of static pressure non-uniformity. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of flow measurement within the test flow channel of an existing aero-engine;

[0028] Figure 2 This is a schematic diagram of multiple transient conversion flow measurement instruments arranged circumferentially on the flow channel measurement section provided in the embodiments of this application;

[0029] Figure 3 This is a side view of the arrangement of measuring points on the cross section of the transient conversion flow measurement instrument support rod provided in this application embodiment;

[0030] Figure 4 This is a cross-sectional view of the arrangement of measuring points on the cross section of the transient conversion flow measurement instrument support rod provided in this application embodiment;

[0031] in:

[0032] 1-Flow channel; 2-Transient conversion flow measurement instrument; 3-Support rod; 4-Measuring stack;

[0033] A - Total pressure measurement point;

[0034] B - Static pressure measuring point.

[0035] To better illustrate this embodiment, some parts in the accompanying drawings may be omitted, enlarged, or reduced, and do not represent the actual size of the product. Furthermore, the accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. Detailed Implementation

[0036] 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.

[0037] 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.

[0038] 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.

[0039] The following is in conjunction with the appendix Figures 1 to 4 This application will be described in further detail.

[0040] A method for measuring transient flow rate in a test flow channel of an aero-engine, comprising:

[0041] On the measuring section of the flow channel (1), multiple transient conversion flow measuring instruments (2) are arranged circumferentially, such as Figure 2 As shown, where:

[0042] The support rod (3) of each transient conversion flow measurement instrument (2) extends into the flow channel (1), and multiple measurement stacks (4) are arranged radially;

[0043] At the leading edge of the section where each measuring stack (4) is located, a total pressure measuring point (A) is set facing the incoming flow direction of the flow channel (1), and static pressure measuring points (B) perpendicular to the airflow direction inside the flow channel (1) are set on both sides, such as Figure 3 , 4 As shown;

[0044] Calculate the transient flow rate within flow channel (1):

[0045]

[0046]

[0047] in,

[0048] W represents the transient flow rate within channel (1);

[0049] K W The flow coefficient inside the flow channel (1) is obtained by measuring the boundary layer inside the flow channel (1);

[0050] m is the gas dynamics coefficient inside the flow channel (1);

[0051] A e The effective flow area of ​​the flow channel (1) is equal to the measured cross-sectional area of ​​the flow channel (1) minus the windward area of ​​each support rod (3);

[0052] γ is the specific heat ratio of the airflow in channel (1);

[0053] R is the gas constant;

[0054] P t The average total pressure of the airflow in the flow channel (1) is measured at each total pressure measuring point (A);

[0055] P s The average static pressure of the airflow in the flow channel (1) is measured at each static pressure measuring point (B).

[0056] For the transient flow measurement method in the test flow channel of the aero-engine disclosed in the above embodiments, those skilled in the art will understand that it is designed to arrange multiple transient conversion flow measurement instruments 2 circumferentially on the measurement section of the flow channel 1. The support rod 3 of each transient conversion flow measurement instrument 2 extends into the flow channel 1. Multiple measurement stacks 4 are arranged radially. The total pressure measurement point A at the leading edge of the section where each measurement stack 4 is located is designed, and static pressure measurement points B are set on both sides. Then, the transient flow rate is calculated by the measurement value of each measurement point, which can meet the response requirements of transient flow rate change and accurately capture the static pressure non-uniformity characteristics.

[0057] Each transient flow measurement instrument has at least 3 radially upward measuring stacks (2 support rods 3 and 3), arranged according to the form of an equal toroidal surface.

[0058] The aperture of each total pressure measuring point A and static pressure measuring point B is 0.5-1mm.

[0059] Chamfer the inlet of each total pressure measuring point A, with a chamfer size of 0.2mm.

[0060] The center line of each static pressure measuring point B hole is perpendicular to the surface of the corresponding support rod 3, the opening edge is sharp and burr-free, and chamfering is not allowed.

[0061] In each transient flow measuring instrument 2, the inner diameter of the pressure lead-out pipe of the total pressure measuring point A and the static pressure measuring point B is consistent with the orifice diameter of the measuring point.

[0062] In each transient flow meter 2, the pressure outlet pipes of the total pressure measuring point A and static pressure measuring point B are allowed to turn slowly, but not sharply. The turning form and number of all pressure outlet pipes are the same, and the inner diameter of each pressure outlet pipe gradually decreases.

[0063] The total length of the pressure lead-out pipelines of the total pressure measuring point A and static pressure measuring point B in each transient flow measuring instrument 2 is the length from the total pressure measuring point A and static pressure measuring point B to the pressure measuring module. The pressure lead-out pipelines of the total pressure measuring point A and static pressure measuring point B are designed as an integrated unit with a consistent total length, ranging from 0.5 to 2 m.

[0064] Each transient flow meter 2 is connected to a pressure measurement module that has high-speed acquisition capability and a response frequency of not less than 100Hz.

[0065] 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 transient flow rate in a test flow channel of an aero-engine, characterized in that, include: On the measuring section of the flow channel (1), multiple transient conversion flow measuring instruments (2) are arranged circumferentially, wherein: The support rod (3) of each transient conversion flow measurement instrument (2) extends into the flow channel (1), and multiple measurement stacks (4) are arranged radially; Each measuring stack (4) has a total pressure measuring point (A) facing the direction of the incoming flow of the flow channel (1) at the front edge of the cross section, and static pressure measuring points (B) perpendicular to the direction of the airflow in the flow channel (1) are set on both sides. Calculate the transient flow rate within flow channel (1): in, W represents the transient flow rate within channel (1); K W The flow coefficient within the flow channel (1); m is the gas dynamics coefficient inside the flow channel (1); A e The effective flow area of ​​the flow channel (1); γ is the specific heat ratio of the airflow in channel (1); R is the gas constant; P t The average total pressure of the airflow in the flow channel (1) is measured at each total pressure measuring point (A); P s The average static pressure of the airflow in the flow channel (1) is measured at each static pressure measuring point (B).

2. The method for measuring transient flow rate in the test flow channel of an aero-engine according to claim 1, characterized in that, K W The value is obtained by measuring the inner surface layer of the flow channel (1).

3. The method for measuring transient flow rate in the test flow channel of an aero-engine according to claim 1, characterized in that, 4. The method for measuring transient flow rate in the test flow channel of an aero-engine according to claim 1, characterized in that, A e The value is equal to the cross-sectional area of ​​the flow channel (1) minus the windward area of ​​each support rod (3).

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