CN-121762228-B - Aeroengine flow field control method and system with inertial separation air inlet channel

CN121762228BCN 121762228 BCN121762228 BCN 121762228BCN-121762228-B

Abstract

The invention discloses an aeroengine flow field control method and system with an inertial separation air inlet channel, wherein the flow field control method comprises the following steps of S1, setting an air extraction unit connected with a bypass channel, a sensing unit arranged on the bypass channel and a control unit respectively connected with the air extraction unit and the sensing unit, S2, obtaining a flight task spectrum of the aeroengine to determine a pneumatic simulation boundary condition of the inertial separation air inlet channel, S3, developing three-dimensional pneumatic simulation of the inertial separation air inlet channel to obtain bypass channel target flow of the aeroengine in different working states, and S4, based on the bypass channel target flow of the aeroengine in different working states, carrying out closed-loop feedback control on the bypass channel actual flow according to the current working state of the aeroengine, so that the reliability of ground bench test data and the effectiveness of performance test of the aeroengine are improved.

Inventors

YANG YANG
Song Minna
LI GAIQI
Ding Runhan
LIU XIANZHONG
MA DONGYANG
ZHAO SIRUI
XIE RONGHUA
SONG MINGBO

Assignees

中国航发湖南动力机械研究所

Dates

Publication Date: 20260512
Application Date: 20260228

Claims (10)

1. The flow field control method of the aeroengine with the inertial separation air inlet channel is used for controlling the flow field in the inertial separation air inlet channel of the aeroengine in a ground bench test, and the inertial separation air inlet channel comprises an air inlet, a bypass channel and an engine air inlet channel, and is characterized by comprising the following steps: S1, arranging an air extraction unit connected with a bypass channel, a sensing unit arranged on the bypass channel and a control unit respectively connected with the air extraction unit and the sensing unit; s2, acquiring a flight task spectrum of the aeroengine to determine a pneumatic simulation boundary condition of an inertial separation air inlet channel; s3, developing three-dimensional pneumatic simulation of an inertial separation air inlet channel to obtain target flow of a bypass channel of the aeroengine in different working states; And S4, based on the target flow of the bypass channel of the aero-engine in different working states, the control unit, the sensing unit and the air extraction unit are matched during the ground bench test, and the actual flow of the bypass channel is subjected to closed-loop feedback control according to the current working state of the aero-engine.
2. The method for controlling a flow field of an aircraft engine with an inertial separation inlet according to claim 1, wherein S2 comprises the steps of: s21, acquiring a flight task spectrum of the aero-engine to determine the flight speed, the flight height and the working parameters of the aero-engine in different working states; s22, calculating according to the flight speed and the flight height of the aero-engine in different working states and a standard atmosphere model to obtain the total pressure and the total temperature direction of free inflow; S23, calculating to obtain the outlet flow of an engine air inlet channel according to working parameters of the aeroengine in different working states and an engine characteristic diagram or an engine performance model; S24, the total pressure and the total gentle direction of the free incoming flow form an inlet boundary condition in the pneumatic simulation boundary condition, and the outlet flow of the engine air inlet channel forms an outlet boundary condition in the pneumatic simulation boundary condition.
3. The method for controlling a flow field of an aircraft engine with an inertial separation inlet according to claim 1, wherein S3 comprises the steps of: s31, establishing a three-dimensional geometric model of an inertial separation air inlet channel; S32, importing the three-dimensional geometric model into CFD preprocessing software to generate a calculation grid; s33, setting a pneumatic simulation boundary condition in a CFD solver, and calculating to obtain a flow field simulation result; s34, extracting and recording the target flow of the bypass channel of the aeroengine in different working states from the flow field simulation result.
4. The method for controlling a flow field of an aircraft engine with an inertial separation inlet according to claim 3, wherein when generating the computational grid, local grid encryption is performed in critical areas of flow separation and convergence.
5. The flow field control method for an aircraft engine with an inertial separation inlet according to claim 4, wherein when generating the calculation grids, the number of calculation grids y+ near the wall is set to 1, and different numbers of calculation grids which are sequentially increased are set, and pneumatic simulation is performed respectively to select the number of grids when the pressure ratio of the inlet section of the inlet to the bypass outlet section is stable.
6. The method for controlling a flow field of an aircraft engine with an inertial separation inlet according to any one of claims 1-5, wherein S4 comprises the steps of: s41, constructing a mapping table or fitting the mapping table into a control curve for the target flow of a bypass channel of the aero-engine in different working states, and conveying the mapping table or the control curve to a control unit; S42, during ground bench test, the control unit inquires from the mapping table or calculates through a control curve according to the working parameters of the aero-engine in the current working state to obtain the target flow of the bypass channel of the aero-engine in the current working state, and simultaneously the sensing unit measures and feeds back the actual flow of the bypass channel to the control unit in real time; and S43, the control unit controls the air extraction capacity of the air extraction unit according to the difference value between the actual flow of the bypass channel and the target flow of the bypass channel, so that the actual flow of the bypass channel tracks the target flow of the bypass channel until the difference value is zero.
7. The method of controlling an aircraft engine flow field with an inertial separation inlet according to any one of claims 1-5, wherein the bypass channel target flow includes mass flow, average flow rate and pressure distribution across the outlet cross section of the bypass channel.
8. The method of controlling an aircraft engine flow field with inertial separation inlet according to any one of claims 1-5, wherein operating conditions include take-off, climb, cruise, maneuver and descent.
9. The method of controlling an aircraft engine flow field with an inertial separation inlet according to any one of claims 1-5, wherein the extraction unit comprises an extraction duct in communication with the bypass duct and an extraction fan disposed within the extraction duct.
10. An aeroengine flow field control system with an inertial separation air inlet channel, which is characterized in that the aeroengine flow field control method with the inertial separation air inlet channel is adopted, and the aeroengine flow field control system with the inertial separation air inlet channel comprises an inertial separation air inlet channel, an air exhaust unit, a control unit and a sensing unit, wherein the inertial separation air inlet channel comprises an air inlet, a bypass channel and an engine air inlet channel, the air exhaust unit comprises an air exhaust pipeline communicated with the bypass channel and an air exhaust fan arranged in the air exhaust pipeline, and the control unit is respectively connected with the air exhaust fan and the sensing unit.

Description

Aeroengine flow field control method and system with inertial separation air inlet channel Technical Field The invention relates to the technical field of aero-engine tests, in particular to an aero-engine flow field control method with an inertial separation air inlet channel. In addition, the invention also relates to a control system comprising the aeroengine flow field control method with the inertial separation air inlet structure. Background In an aeroengine, an inertial separation air inlet mainly comprises an air inlet, an engine air inlet and a bypass channel, air flow is sucked from the air inlet and respectively enters the engine air inlet and the bypass channel, the air flow entering the engine air inlet is sucked by the aeroengine, and the air flow entering the bypass channel is directly discharged to the atmosphere. At the branch point between the engine air inlet channel and the bypass channel, through the change of the air flow direction, the solid particles with larger inertia such as the inhaled hail, sand particles and the like can be separated from the bypass channel, so that the solid particles entering the engine air inlet channel are reduced, and the damage to the aeroengine is reduced. During ground bench test, the air inlet and the outlet of the bypass channel are both in the atmospheric environment, the air pressure is the atmospheric pressure, and under the suction action of the engine, the air pressure at the air inlet channel of the engine is negative pressure (namely lower than the atmospheric pressure), so that the air flow can be sucked into the aeroengine from the air inlet and the bypass channel at the same time. When the aircraft is actually flying, the ram effect caused by the flying speed of the aircraft can cause the gas pressure at the air inlet to be higher than the atmospheric pressure. The stamping effect refers to the phenomenon that when an air inlet is faced to high-speed incoming flow in the flight process of an aircraft, the kinetic energy of the air flow is partially converted into pressure energy. According to Bernoulli's principle, the gas is retarded and decelerated at the leading edge of the inlet channel, and kinetic energy is converted into pressure energy, so that the total pressure of the gas at the inlet channel of the engine is higher than the atmospheric pressure. Thus, in actual flight of the aircraft, the direction of the air flow in the bypass channel is discharged to the atmosphere. That is, the bypass airflow direction during the ground bench test is opposite to the bypass airflow direction during the actual flight of the aircraft. Although in the examination subjects of partial ground bench test, the difference of the air flow direction of the bypass channel has no influence on the examination result of the aero-engine, such as structural and lubricating oil test subjects with vibration, gesture and the like which have no strict requirements on the performance of the engine. However, in the examination subjects with requirements on the performance of the aero-engine, such as test subjects of high altitude bench test, endurance test, life test and the like, the difference of the air flow direction of the bypass channel can cause the difference of air inlet loss and inlet flow field distribution of the aero-engine in the ground bench test relative to actual flight, such as increased air inlet loss and uneven inlet flow field distribution. The increased intake losses may result in a drop in the overall inlet pressure of the aircraft engine, reducing the available air flow and compressor efficiency of the aircraft engine, which in turn affects the thrust (or power) and fuel economy of the aircraft engine. Uneven distribution of the inlet flow field (such as existence of rotational flow and distortion) can cause stall and surge of the compressor, and influence the stable working range of the aeroengine. These differences can seriously affect the effectiveness of the assessment. Disclosure of Invention The invention provides a flow field control method and a flow field control system for an aeroengine with an inertial separation air inlet channel, which are used for solving the technical problem that the effectiveness of the existing ground bench test on performance assessment of the aeroengine with the inertial separation air inlet channel is low. According to one aspect of the invention, there is provided an aircraft engine flow field control method with an inertial separation inlet for controlling a flow field in the inertial separation inlet of an aircraft engine during ground bench test, the inertial separation inlet comprising an inlet, a bypass channel and an engine inlet, the flow field control method comprising the steps of S1 providing an air extraction unit connected with the bypass channel, a sensing unit arranged on the bypass channel, and a control unit connected with the air extraction unit and the sensing unit, respectively; the meth