A method for measuring cold air flow in the inner cavity of a bidirectional inlet guide vane

Abstract

The present invention discloses a method for measuring the cold air flow rate in the inner cavity of a bidirectional air inlet guide vane. The method uses a bidirectional air inlet guide vane inner cavity cold air flow measurement device to split the airflow into two paths and pass them into the inner cavity of the bidirectional air inlet guide vane to complete the ventilation measurement step. Splitting the airflow into two paths and passing them into the inner cavity of the bidirectional air inlet guide vane solves the problem that the existing technology can only measure the cold air flow rate of the guide vane's unidirectional air inlet, but cannot measure the cold air flow rate of the guide vane's bidirectional air inlet.

Description

Technical Field

[0001] The invention relates to a method for measuring cold air flow in an inner cavity of a bidirectional air inlet guide blade, belonging to the technical field of aeroengines. Background Art

[0002] Ground testing of aircraft engines and their components is essential for engine design and development. They are used to measure various product performance parameters, with air flow being a crucial parameter. During engine development and design, a comprehensive and accurate air system model must be established, along with the flow characteristics of corresponding components along the flow path. Cold air flow measurement is also required for high-pressure turbines with bidirectional air intakes in dual, triple, or quadruple guide vanes.

[0003] However, the existing technology (a turbine blade air flow test device with Chinese patent publication number CN114894260A, the disclosed content is: the turbine blade to be tested is clamped in a clamping block, the pressure stabilizing chamber is connected to the air flow pipeline of the flow tester, and the air flow enters the pressure stabilizing chamber) can only measure the cold air flow of the one-way air intake of the guide blade, but cannot measure the cold air flow of the guide blade with two-way air intake. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a method for measuring the cold air flow rate in the inner cavity of a bidirectional inlet guide vane.

[0005] The present invention is achieved through the following technical solutions.

[0006] The present invention provides a method for measuring cold air flow in the inner cavity of a bidirectional air inlet guide vane, which uses a bidirectional air inlet guide vane inner cavity cold air flow measuring device to split the airflow into two paths and pass them into the inner cavity of the bidirectional air inlet guide vane to complete the ventilation measurement step of the measurement.

[0007] The ventilation measurement steps are as follows: gas is introduced into the mass flow meter, the airflow is divided into two paths through the three-way structure and flows into two drainage hoses respectively, and then transmitted to the upper pressure stabilizing box and the lower pressure stabilizing box. The airflow is divided into two paths and flows into the inner cavity with two-way air inlet guide blades, and then the gas flows out from the air film holes or trailing edge slits that do not need to be blocked.

[0008] The ventilation measurement step further includes: obtaining the intake gas temperature T by a temperature sensor t , obtain the intake gas pressure parameter value P through the pressure sensor t , obtain the physical flow rate W of the intake gas through the mass flow meter, and calculate the converted flow rate W measured by the blade according to the conversion flow calculation formula cor .

[0009] The converted flow rate W corThe calculation is completed according to the following conversion flow calculation formula:

[0010]

[0011] Where:

[0012] W cor ——Converted flow rate, mm 2 K 0.5 / s;

[0013] W——physical flow rate, kg / s;

[0014] T t ——Total temperature at blade inlet, K;

[0015] P t ——Inlet air pressure Pa.

[0016] Before the ventilation measurement step, a measurement device docking step is also included. The measurement device is: one drainage tube is connected to the upper pressure stabilizing box horn interface on the blade clamp, and the other drainage tube is connected to the lower clamp horn interface on the blade clamp.

[0017] Before the measuring device docking step, the method further includes sealing the air film holes, wherein the air film holes are sealed and blocked using epoxy resin on the test piece composed of the bidirectional air inlet guide vanes.

[0018] Before the step of sealing the air film holes, a pre-installation step of the test piece is also included. The pre-installation of the test piece is as follows: the lower air inlet of the test piece formed by the two-way air inlet guide vane is fixedly connected with the lower pressure stabilizing box and the lower clamp; the upper air inlet of the test piece is fixedly connected with the upper clamp and the upper pressure stabilizing box; the upper clamp, the upper pressure stabilizing box, the lower pressure stabilizing box and the lower clamp constitute a blade clamp, and the test piece is installed on the blade clamp, so that the two-way air inlet of the test piece is connected to the upper interface of the blade clamp in an empty state.

[0019] The bidirectional inlet guide vane inner cavity cold air flow measurement device comprises:

[0020] Intake pipe;

[0021] a mass flow meter, the mass flow meter being connected to an air inlet port of the air inlet pipe;

[0022] A three-way structure, the air inlet end of the three-way structure is connected to the air outlet end of the air inlet pipe, and a temperature sensor and a pressure sensor are arranged on the three-way structure at the transfer end of the air inlet pipe;

[0023] There are two drainage tubes, and the two drainage tubes are correspondingly connected to the two air outlet ports of the three-way structure.

[0024] The three-way structure is connected to the air intake pipe via a steel pipe with a reducer and reducer structure, and the pressure sensor is installed on the large end of the reducer and reducer.

[0025] The beneficial effect of the present invention is that it can divide the airflow into two paths and pass them into the inner cavity of the bidirectional air intake guide vane, solving the problem that the existing technology can only measure the cold air flow of the one-way air intake of the guide vane, but cannot measure the cold air flow of the bidirectional air intake guide vane. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the test piece, measuring device, and blade fixture of the present invention after docking and installation;

[0027] Figure 2 This is a schematic diagram of the test piece and the blade fixture of the present invention after docking and installation;

[0028] In the figure: 1-bolt; 2-nut; 3-gasket; 4-upper pressure stabilizing box; 5-upper fixture; 6-test piece; 7-lower pressure stabilizing box; 8-lower fixture; 9-drainage tube; 10-tee structure; 11-temperature sensor; 12-pressure sensor; 13-large end; 14-large and small ends; 15-intake pipe; 16-mass flow meter. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0030] like Figures 1 to 2 shown.

[0031] The present invention provides a method for measuring the cold air flow rate in the inner cavity of a bidirectional inlet guide vane, which is based on the need to use a bidirectional inlet guide vane inner cavity cold air flow rate measurement device, and includes the following steps:

[0032] Step 1: Pre-install the test piece: Securely connect the lower air inlet of the test piece 6, which consists of the bidirectional air inlet guide vanes, to the lower pressure stabilizing box 7 and the lower fixture 8. A 3mm thick rubber pad, coated with AB glue, is installed between the lower pressure stabilizing box 7 and the lower fixture 8. The resulting seal can withstand pressures up to 300 kPa without leakage. The lower pressure stabilizing box 7 and the lower fixture 8 are secured using fasteners consisting of bolts 1, nuts 2, and washers 3.

[0033] The air inlet on the upper part of the test piece 6 is fixedly connected to the upper fixture 5 and the upper pressure-stabilizing box 4. A 3mm thick rubber pad is installed between the upper fixture 5 and the upper pressure-stabilizing box 4 and is coated with AB glue. The formed sealing structure can withstand a pressure of up to 300KPa without leakage. The upper fixture 5 and the upper pressure-stabilizing box 4 are fixed by fasteners consisting of bolts 1, nuts 2, and gaskets 3. The external part of the docking port of the upper pressure-stabilizing box 4 and the lower fixture 8 is trumpet-shaped to be pressed and connected with the corresponding drainage pipe 9; the upper fixture 5, the upper pressure-stabilizing box 4, the lower pressure-stabilizing box 7 and the lower fixture 8 constitute a blade fixture, and the test piece 6 is installed on the blade fixture to realize the two-way air inlet of the test piece 6 connected to the upper interface of the blade fixture in an empty state;

[0034] Step 2: Block the air film holes; Use epoxy resin to seal the air film holes that need to be blocked on the test piece 6 composed of the two-way air inlet guide vanes. The epoxy resin is used for blocking. At a temperature range of -5°C to 25°C, the air film holes can be blocked for about 5 minutes. The blocking is firm and easy to remove after the test.

[0035] Step three, docking the measuring device: one drainage tube 9 is connected to the speaker interface of the upper pressure regulating box 4 on the blade fixture, and the other drainage tube 9 is connected to the speaker interface of the lower fixture 8 on the blade fixture, preparing for the air flow to pass through the two drainage tubes 9 of the two-way air inlet guide vane inner cavity cold air flow measuring device to be connected to the double inner cavity of the guide vane.

[0036] Step 4, ventilation measurement: gas is introduced into the mass flow meter 16, and the air flow is divided into two paths through the three-way structure 10 and correspondingly passed into the two drainage hoses 9, and then conducted to the upper pressure regulating box 4 and the lower pressure regulating box 7. The air flow is divided into two paths and passed into the inner cavity of the two-way air intake guide vane, solving the problem that the existing technology can only measure the cold air flow of the one-way air intake of the guide vane, but cannot measure the cold air flow of the two-way air intake guide vane. Then the gas flows out from the air film hole or the trailing edge slit that does not need to be blocked; the intake gas temperature T is obtained through the temperature sensor 11 t , obtain the intake gas pressure parameter value P through the pressure sensor 12 t , obtain the physical flow rate W of the intake gas through the mass flow meter 16, and calculate the converted flow rate W measured by the blade according to the conversion flow calculation formula cor , the conversion flow calculation formula is as follows:

[0037]

[0038] Where:

[0039] W cor ——Converted flow rate, mm 2 K 0.5 / s;

[0040] W——physical flow rate, kg / s;

[0041] T t ——Total temperature at blade inlet, K;

[0042] P t ——Inlet air pressure pa.

[0043] After the above four steps have been completed to measure the flow rate in each chamber of the guide vanes under one blocking scheme, the guide vanes under the next blocking scheme are replaced by removing the drainage tube 9, and the cycle is repeated to complete the flow rate measurement of each chamber of the vanes under different blocking schemes. Step 2 can also be performed after step 3 or before step 1.

[0044] The present application discloses a bidirectional inlet guide vane inner cavity cold air flow measurement device, comprising:

[0045] The air inlet pipe 15 is made of a steel pipe, and the air inlet port of the air inlet pipe 15 is connected to a mass flow meter 16 with an accuracy of 0.5%. The mass flow meter 16 is a mass flow meter used to measure the air flow entering the inner cavity of the blade.

[0046] The three-way structure 10 is connected to the air inlet end and the air outlet end of the air inlet pipe 15. The three-way structure 10 at the adapter end of the air inlet pipe 15 is provided with sensors for collecting parameters such as temperature and pressure. For example, a temperature sensor 11 is installed to measure the intake temperature parameter value, and a pressure sensor 12 is installed to measure the intake pressure parameter value. The three-way structure 10 is connected to the air inlet pipe 15 through a steel pipe with a reducer and reducer 14 structure, and the pressure sensor 12 is installed on the large end 13 of the reducer and reducer 14.

[0047] There are two drainage pipes 9 corresponding to the two air outlet ports of the three-way structure 10. The drainage pipes 9 can divide the airflow entering from the mass flow meter 16 into two paths and pass them into the inner cavity of the two-way air intake guide vane, solving the problem that the existing technology can only measure the cold air flow of the one-way air intake of the guide vane, but cannot measure the cold air flow of the two-way air intake guide vane.

[0048] The drainage tube 9 is made of rubber or other materials to withstand high gas pressure. The drainage hose is about 20 cm long and has good flexibility, which can be easily connected to the pressure regulating box for installation. The drainage tube 9 is made of nylon rubber or other materials to withstand high gas pressure ≮1MPa.

Claims

1. A method for measuring the cold air flow rate in the inner cavity of a bidirectional inlet guide vane, characterized in that: The method comprises the steps of using a bidirectional air inlet guide vane inner cavity cold air flow measurement device to split the air flow into two paths and pass them into the inner cavity of the bidirectional air inlet guide vane to complete the measurement; The ventilation measurement steps are as follows: gas is introduced into the mass flow meter (16), the gas flow is divided into two paths through the three-way structure (10) and flows into two drainage hoses (9) respectively, and then is conducted to the upper pressure stabilizing box (4) and the lower pressure stabilizing box (7), and the gas flow is divided into two paths and flows into the inner cavity of the two-way air inlet guide vane, and then the gas flows out from the air film hole or the trailing edge slit that does not need to be blocked; The ventilation measurement step further includes: obtaining the intake gas temperature T by a temperature sensor (11) t , obtain the intake gas pressure parameter value P through the pressure sensor (12) t , obtain the physical flow rate W of the intake gas through the mass flow meter (16), and calculate the converted flow rate W measured by the blade according to the conversion flow calculation formula cor ; The converted flow rate W cor The calculation is completed according to the following conversion flow calculation formula: Where: W cor ——Converted flow rate, mm 2 K 0.5 / s; W——physical flow rate, kg / s; T t ——Total temperature at blade inlet, K; P t ——Inlet air pressure, pa.

2. The method for measuring the cold air flow rate in the inner cavity of a bidirectional inlet guide vane according to claim 1, characterized in that: Before the ventilation measurement step, a measurement device docking step is also included, wherein the measurement device comprises: a drainage tube (9) correspondingly connected to the horn interface of the upper pressure stabilizing box (4) on the blade fixture, and another drainage tube (9) correspondingly connected to the horn interface of the lower fixture (8) on the blade fixture.

3. The method for measuring the cold air flow rate in the inner cavity of a bidirectional inlet guide vane according to claim 2, characterized in that: Before the step of docking the measuring device, the method further includes sealing the air film holes, wherein the air film holes are sealed and blocked using epoxy resin on the test piece (6) composed of the bidirectional air inlet guide vanes.

4. The method for measuring the cold air flow rate in the inner cavity of a bidirectional inlet guide vane according to claim 3, characterized in that: Before the step of sealing the air film hole, a pre-installation step of the test piece is also included. The pre-installation of the test piece is as follows: the lower air inlet of the test piece (6) formed by the two-way air inlet guide blade is fixedly connected to the lower pressure stabilizing box (7) and the lower clamp (8); the upper air inlet of the test piece (6) is fixedly connected to the upper clamp (5) and the upper pressure stabilizing box (4); the upper clamp (5), the upper pressure stabilizing box (4), the lower pressure stabilizing box (7) and the lower clamp (8) constitute a blade clamp, and the test piece (6) is installed on the blade clamp, so that the two-way air inlet of the test piece (6) is connected to the upper interface of the blade clamp in an empty state.

5. The method for measuring the cold air flow rate in the inner cavity of a bidirectional inlet guide vane according to claim 4, characterized in that: The bidirectional inlet guide vane inner cavity cold air flow measurement device comprises: Intake pipe (15); A mass flow meter (16), the mass flow meter (16) is connected to the air inlet port of the air inlet pipe (15); A three-way structure (10), wherein the air inlet end of the three-way structure (10) is connected to the air outlet end of the air inlet pipe (15), and a temperature sensor (11) and a pressure sensor (12) are arranged on the three-way structure (10) at the transition end portion thereof to the air inlet pipe (15); There are two drainage tubes (9), and the two drainage tubes (9) are correspondingly connected to the two air outlet ports of the three-way structure (10).

6. The method for measuring cold air flow in the inner cavity of a bidirectional inlet guide vane according to claim 1, characterized in that: The three-way structure (10) is connected to the air intake pipe (15) via a steel pipe with a reducer (14) structure, and the pressure sensor (12) is installed on the large end (13) of the reducer (14).

Images