Method for measuring and calculating transition-state oil supply amount of aero-engine based on oil supply pressure difference

Abstract

The invention belongs to the field of aero-engine transition state control, and particularly relates to a method for measuring and calculating the aero-engine transition state oil supply amount based on the oil supply pressure difference. According to the technical scheme, the method for measuring and calculating the transition-state oil supply amount of the aero-engine based on the oil supply pressure difference comprises the following steps that (1) the steady-state oil supply pressure difference and the steady-state oil supply amount of the engine are obtained; (2) the engine transition state oil supply pressure difference is obtained; (3) the engine transition state oil supply amount is calculated; and 4) forming an engine transition state characteristic curve graph. According to the method for measuring and calculating the transition state oil supply amount of the aero-engine based on the oil supply pressure difference, the relation between the steady state oil supply amount and the oil supply pressure difference of the aero-engine is obtained, the oil supply amounts of different transition states are obtained through calculation, and an engine transition state characteristic curve graph is formed and used for analyzing and processing various transition state problems.

Description

Technical Field

[0001] The present invention belongs to the field of aircraft engine transient state control, and in particular relates to a method for calculating the transient state fuel supply amount of an aircraft engine based on the fuel supply pressure difference. Background Art

[0002] Aircraft engines are the core power units of aircraft, and their transient state performance is crucial. Various control issues often arise during this state. To support the analysis and resolution of these engine transient state issues, it is necessary to obtain relatively accurate fuel flow rates during this state. This allows for the plotting of fuel flow rates versus converted speed (N2R) during this state, providing a basis for analyzing and resolving these issues. However, due to limitations in existing measurement methods and sensors, the measurement error of transient state fuel flow rates is significant, making it ineffective data for problem analysis. Summary of the Invention

[0003] The present invention provides a method for calculating the fuel supply amount of an aircraft engine in a transient state based on the fuel supply pressure difference. By obtaining the relationship between the steady-state fuel supply amount and the fuel supply pressure difference of the aircraft engine, the fuel supply amount in different transient states is calculated, and a transient state characteristic curve diagram of the engine is formed, which is used to analyze and process various transient state problems.

[0004] The technical solutions of the present invention are as follows:

[0005] A method for calculating the transient fuel supply amount of an aircraft engine based on the fuel supply pressure difference comprises the following steps:

[0006] 1) Obtain the engine steady-state fuel supply pressure difference and steady-state fuel supply amount;

[0007] a. Determine the engine speed range based on the engine model and the transition speed range requirements, ensuring that the transition speed range is between the engine's starting and ending speeds. Set the speed step size to 3-5%. Calculate the steady-state high-pressure converted speed N2R value for the starting speed, each speed step point, and the ending speed.

[0008] b. Use a pressure sensor and a flow sensor to measure the pressure in front of the combustion chamber nozzle, the back pressure behind the nozzle, and the steady-state fuel supply at the starting speed, each speed step point, and the end speed. The difference between the pressure in front of the combustion chamber nozzle and the back pressure behind the nozzle is calculated as the fuel supply pressure difference;

[0009] c. List the steady-state high-pressure converted speed N2R value and the corresponding steady-state oil supply pressure difference and steady-state oil supply quantity in a steady-state oil supply pressure difference and steady-state oil supply quantity correspondence table;

[0010] 2) Obtaining the engine transient fuel supply pressure difference;

[0011] The engine implements a specified transition state process, with each throttle operation time being consistent and the process being continuous. The pressure in front of the combustion chamber nozzle and the back pressure behind the nozzle are measured from the moment the throttle is pushed up or down to the time when the speed stabilizes. The fuel supply pressure difference is calculated from the moment the throttle is pushed up or down to the time when the speed stabilizes. The data of the fuel supply pressure difference changing over time from the moment the throttle is pushed up or down to the time when the speed stabilizes is recorded. A graph of the fuel supply pressure difference changing over time from the time when the engine changes from a low speed state to a high speed state is drawn with time as the horizontal axis and the transition state fuel supply pressure difference as the vertical axis. At the same time, the corresponding transition state high pressure converted speed N2R value changing over time is recorded.

[0012] 3) Calculate the engine's transient fuel supply;

[0013] Calculate the transition state fuel supply quantity corresponding to each transition state fuel supply pressure difference using the interpolation calculation formula;

[0014] 4) forming an engine transient characteristic curve diagram;

[0015] The engine transition state characteristic curve is formed with the transition state high pressure converted speed N2R value as the horizontal axis and the transition state fuel supply as the vertical axis, which is used to analyze the transition state fuel supply of the engine in different speed ranges.

[0016] Furthermore, in the method for calculating the transient fuel supply amount of an aircraft engine based on the fuel supply pressure difference, the interpolation calculation formula is as follows:

[0017] Wf g =(Wf n+1 -Wf n )*(P g -P n ) / (P n+1 -P n )+Wf n

[0018] Where: Wf g is the transition state fuel supply; P g is the transition state oil supply pressure difference; P g The value of the two adjacent steady-state oil supply pressure differences P in the steady-state oil supply pressure difference and steady-state oil supply amount correspondence table is n and P n+1 Between; P n The corresponding steady-state oil supply is Wf n ;P n+1 The corresponding steady-state oil supply is Wf n+1 ;n=1, 2, 3….

[0019] The beneficial effects of the present invention are as follows: the present invention can obtain the transient fuel supply of an aircraft engine to study the transient state problem of the engine, evaluate the stable operating margin of the engine with the same transient fuel supply, and provide a guarantee for the safe use of the engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A graph showing the change of the engine transient fuel supply pressure difference over time;

[0021] Figure 2 This is the engine transient characteristic curve. DETAILED DESCRIPTION

[0022] A method for calculating the transient fuel supply amount of an aircraft engine based on the fuel supply pressure difference comprises the following steps:

[0023] 1) Obtain the engine steady-state fuel supply pressure difference and steady-state fuel supply amount;

[0024] a. Determine the engine speed range based on the engine model and the transition speed range requirements, ensuring that the transition speed range is between the engine's starting and ending speeds. Set the speed step size to 5%. Calculate the steady-state high-pressure converted speed N2R values ​​for the starting speed, each speed step point, and the ending speed.

[0025] b. Use a pressure sensor and a flow sensor to measure the pressure in front of the combustion chamber nozzle, the back pressure behind the nozzle, and the steady-state fuel supply at the starting speed, each speed step point, and the end speed. The difference between the pressure in front of the combustion chamber nozzle and the back pressure behind the nozzle is calculated as the fuel supply pressure difference;

[0026] c. List the steady-state high-pressure converted speed N2R value and the corresponding steady-state oil supply pressure difference and steady-state oil supply quantity in a corresponding table, see Table 1 below; the steady-state oil supply quantity is directly proportional to the steady-state oil supply pressure difference;

[0027] Table 1 Correspondence between steady-state oil supply pressure difference and steady-state oil supply amount

[0028] Serial number N2R, % Steady-state oil supply pressure difference Steady-state fuel supply 1 <![CDATA[X1]]> <![CDATA[P1]]> <![CDATA[Wf1]]> 2 <![CDATA[X2=X1+5]]> <![CDATA[P2]]> <![CDATA[Wf2]]> 3 <![CDATA[X3=X1+10]]> <![CDATA[P3]]> <![CDATA[Wf3]]> ... ... ... ...

[0029] 2) Obtaining the engine transient fuel supply pressure difference;

[0030] The engine implements a specified transition process. Each throttle operation time is consistent and the process is continuous. The pressure in front of the combustion chamber nozzle and the back pressure behind the nozzle are measured from the moment the throttle is pushed up or pulled down to the time when the speed stabilizes. The fuel supply pressure difference is calculated from the moment the throttle is pushed up or pulled down to the time when the speed stabilizes. The fuel supply pressure difference from the moment the throttle is pushed up or pulled down to the time when the speed stabilizes is recorded. The process data of the fuel supply pressure difference from the moment the throttle is pushed up or pulled down to the time when the speed stabilizes is recorded. With time as the horizontal axis and the transition state fuel supply pressure difference as the vertical axis, a curve chart of the fuel supply pressure difference changing with time when the engine changes from a low speed state to a high speed state is drawn, as shown in the figure below. Figure 1 As shown; at the same time, the corresponding transition state high pressure conversion speed N2R value changes with time process data;

[0031] 3) Calculate the engine's transient fuel supply;

[0032] The interpolation calculation formula is used to calculate the transition state fuel supply amount corresponding to each transition state fuel supply pressure difference; the interpolation calculation formula is as follows:

[0033] Wf g =(Wf n+1 -Wf n )*(P g -P n ) / (P n+1 -P n )+Wf n

[0034] Where: Wf g is the transition state fuel supply; P g is the transition state oil supply pressure difference; P g The value of the two adjacent steady-state oil supply pressure differences P in the steady-state oil supply pressure difference and steady-state oil supply amount correspondence table is n and P n+1 Between; P n The corresponding steady-state oil supply is Wf n ;P n+1 The corresponding steady-state oil supply is Wf n+1 ; n = 1, 2, 3, ...;

[0035] 4) forming an engine transient characteristic curve diagram;

[0036] The engine transient characteristic curve is formed by taking the transient high pressure converted speed N2R value as the horizontal axis and the transient fuel supply as the vertical axis, as shown in the figure. Figure 2 As shown; it is used to analyze the transition state fuel supply of the engine in different speed ranges, compare the increase of the transition state fuel supply of the same engine compared with the steady state fuel supply, and compare the difference in the distribution of transition state fuel supply of different engines.

Claims

1. A method for calculating the transient fuel supply amount of an aircraft engine based on the fuel supply pressure difference, characterized in that: The steps include: 1) Obtain the engine steady-state fuel supply pressure difference and steady-state fuel supply amount; a. Determine the engine speed range based on the engine model and the transition speed range requirements, ensuring that the transition speed range is between the engine's starting speed and ending speed; set the speed step size to 3-5%; Calculate the steady-state high-pressure converted speed N2R value of the starting speed, each speed step point and the end speed; b. Use a pressure sensor and a flow sensor to measure the pressure in front of the combustion chamber nozzle, the back pressure behind the nozzle, and the steady-state fuel supply at the starting speed, each speed step point, and the end speed. The difference between the pressure in front of the combustion chamber nozzle and the back pressure behind the nozzle is calculated as the fuel supply pressure difference; c. List the steady-state high-pressure converted speed N2R value and the corresponding steady-state oil supply pressure difference and steady-state oil supply quantity in a steady-state oil supply pressure difference and steady-state oil supply quantity correspondence table; 2) Obtaining the engine transient fuel supply pressure difference; The engine implements a specified transition state process, with each throttle operation time being consistent and the process being continuous. The pressure in front of the combustion chamber nozzle and the back pressure behind the nozzle are measured from the moment the throttle is pushed up or down to the time when the speed stabilizes. The fuel supply pressure difference is calculated from the moment the throttle is pushed up or down to the time when the speed stabilizes. The data of the fuel supply pressure difference changing over time from the moment the throttle is pushed up or down to the time when the speed stabilizes is recorded. A graph of the fuel supply pressure difference changing over time from the time when the engine changes from a low speed state to a high speed state is drawn with time as the horizontal axis and the transition state fuel supply pressure difference as the vertical axis. At the same time, the corresponding transition state high pressure converted speed N2R value changing over time is recorded. 3) Calculate the engine's transient fuel supply; Calculate the transition state fuel supply quantity corresponding to each transition state fuel supply pressure difference using the interpolation calculation formula; 4) forming an engine transient characteristic curve diagram; The engine transition state characteristic curve is formed with the transition state high pressure converted speed N2R value as the horizontal axis and the transition state fuel supply as the vertical axis, which is used to analyze the transition state fuel supply of the engine in different speed ranges.

2. The method for calculating the transient fuel supply amount of an aircraft engine based on the fuel supply pressure difference according to claim 1, characterized in that: The interpolation calculation formula is as follows: Wf g =(Wf n+1 -Wf n )*(P g -P n ) / (P n+1 -P n )+Wf n Where: Wf g is the transition state fuel supply; P g is the transition state oil supply pressure difference; P g The value of the two adjacent steady-state oil supply pressure differences P in the steady-state oil supply pressure difference and steady-state oil supply amount correspondence table is n and P n+1 Between; P n The corresponding steady-state oil supply is Wf n ;P n+1 The corresponding steady-state oil supply is Wf n+1 ; n = 1, 2, 3...

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