A method for estimating the thrust of an aircraft engine based on flight parameters

Abstract

The present application relates to the technical field of aircraft engine simulation design, and particularly relates to a method for estimating aircraft engine thrust based on flight parameters. The aircraft engine thrust estimation method provided by the present application estimates the aircraft engine thrust from the perspective of flight parameter data, in combination with aircraft engine design parameters, taking into account task requirements and adopting the finite element method. Compared with the traditional scheme based on data, i.e., relying on a large amount of flight parameter data and combining statistical rules to obtain the aircraft engine thrust spectrum, the aircraft engine thrust estimation formula derived based on the physical formula has more reliable physical meaning and physical constraints, the distortion degree of the obtained aircraft engine thrust spectrum caused by data sampling error is smaller, the trend and characteristics are more in line with the real rules, and the aircraft engine thrust spectrum has more guiding significance and prediction value, thereby providing strong theoretical support for aircraft engine thrust spectrum prediction.

Description

Technical Field

[0001] This invention relates to the field of aircraft engine simulation design technology, specifically to a method for estimating aircraft engine thrust based on flight parameters. Background Technology

[0002] Aircraft engine thrust is one of the key performance parameters for evaluating the overall performance of an aircraft engine. Chinese patent CN107945615A discloses a method for real-time engine simulation. This invention belongs to the field of flight simulation technology and specifically relates to a method for real-time engine simulation. Regarding the real-time calculation of engine thrust during aircraft flight, it is necessary to first obtain a database of aircraft engine thrust and engine high and low pressure rotational speeds within the entire thrust envelope. Then, based on aircraft and engine state parameters such as altitude, speed, attitude, and throttle position, the thrust generated by the aircraft engine is calculated and matched in real time. This method simulates existing aircraft and engines and is based on existing aircraft and engine data, lacking guiding significance for the development of next-generation aircraft.

[0003] Most existing mature methods for calculating aircraft engine thrust are based on the engine's operating principle, utilizing ground test data and combining it with the thermodynamic parameters of various internal components to obtain the engine thrust spectrum on the ground. After takeoff, by monitoring the thermodynamic parameters of key engine components in the air, such as compressor pressure ratio, turbine inlet gas temperature, total pressure recovery coefficient of various parts, and gas flow rate, the overall engine performance parameters in the air are approximated. However, this performance estimation method separates aircraft performance requirements from the overall engine performance parameters, making it difficult to provide guidance and constraints for engine design work from the perspective of flight parameter data and mission requirements. Summary of the Invention

[0004] To address the technical problem that existing technologies for evaluating aircraft engine thrust separate aircraft performance requirements from comprehensive engine performance parameters, making it difficult to provide guidance and constraints for engine design from a mission-requirement perspective, this invention provides a method for estimating aircraft engine thrust based on flight parameters. The details are as follows:

[0005] This invention provides a method for estimating aircraft engine thrust based on flight parameters, comprising the following steps:

[0006] S100, the complete flight path of a single takeoff and landing of an aircraft is divided into I segments, where i represents the i-th segment in I segment, 1≤i≤I, i∈[1,I];

[0007] S200, calculate the engine thrust value P for each flight segment. i ;

[0008] S201, Read the flight parameters of the i-th segment of the trajectory: Obtain the altitude H of the i-th segment of the trajectory. i Atmospheric density ρ i Velocity v in the track coordinate system i Angle of attack α i Pitch angle Sideslip angle β i Roll angle γ i And the aircraft's fuel capacity (m) fi ;

[0009] S202, specify the aircraft model to be studied, and determine the following aircraft information: Aircraft empty mass (m) e Wing area S, effective aspect ratio λ yx Engine mounting angle Wing angle of attack α0 and elevator deflection angle The slope of the lift line of the entire aircraft at that time

[0010] S203, Determine mission information: Determine the aircraft's effective payload (m) p Unloading quality m′ i Find the mass m of the aircraft on the i-th segment of the trajectory. i ;

[0011] S204, Calculate the aircraft drag Q for the i-th segment of the trajectory. i :

[0012] (C x ) i Let be the drag coefficient of the i-th segment of the trajectory;

[0013] Among them (C) x ) i =(C x0 ) Hi +AC yi 2 (C) x0 ) Hi Let A be the zero-lift drag coefficient for the i-th segment of the trajectory, and C be the lift-induced drag factor. yi Let be the lift coefficient of the i-th segment of the trajectory;

[0014] S205, Calculate the estimated engine thrust P for the i-th segment of the trajectory. i :

[0015] Where θ i Let be the track inclination angle of the i-th segment of the track;

[0016] S300 records the estimated thrust P of the aircraft engine for the i-th segment of the flight path. i And the current aircraft status information, the aircraft status information is Hi v i α i β i , m i .

[0017] Furthermore, in step S204, the lift coefficient C of the i-th segment of the trajectory... yi The formula for calculation is:

[0018] Among them, (α) i -α0) is the effective angle of attack.

[0019] Furthermore, in step S204, the zero-lift drag coefficient (C) of the i-th segment of the trajectory x0 ) Hi The formula for calculation is:

[0020] (C x0 ) Hi =(C x0 ) H＝5 +ΔC x0,Hi , of which (C x0 ) H＝5 ΔC is the reference drag coefficient. x0,Hi This is the altitude correction amount for the i-th segment of the trajectory.

[0021] Furthermore, in step S204, the formula for calculating the lift-induced drag factor A is:

[0022] Where π is the ratio of a circle's diameter to its circumference.

[0023] Furthermore, in step S203, the aircraft mass m of the i-th segment of the trajectory i The formula for calculating m is: i =m e +m p +m fi -m′ i .

[0024] Furthermore, in step S205, the track inclination angle θ of the i-th track segment... i The formula for calculation is:

[0025]

[0026] Furthermore, it also includes a data preprocessing step following S201, which removes outliers from the flight parameters obtained in step S201 and smooths and filters the remaining data.

[0027] Furthermore, it also includes step S400, which follows step S300, based on the engine thrust value P for each flight segment.i Plot the thrust demand curve for an aircraft engine during a single takeoff and landing.

[0028] The beneficial effects of this invention are as follows: The aircraft engine thrust estimation method provided in this application estimates the thrust of an aircraft engine from the perspective of flight parameters, combined with aircraft type parameters, considering mission requirements, and employing the finite element method. It has the following beneficial effects:

[0029] 1. Compared with traditional data-based thrust estimation, which relies on a large amount of flight parameters and engine ground test data, combined with statistical laws to obtain the aircraft engine thrust spectrum, the aircraft engine thrust estimation formula derived in this application based on physical basis formulas has more reliable physical meaning and physical constraints. The obtained aircraft engine thrust spectrum is less distorted by data sampling errors, and its trends and characteristics are more in line with real-world laws. It has more guiding significance and predictive value, and can provide strong theoretical support for the prediction of aircraft engine thrust spectrum.

[0030] 2. Traditional methods separate aircraft performance requirements from engine performance parameters, making it difficult to provide guidance and constraints for engine design from a mission-requirement perspective. This method, however, starts from flight parameters and considers mission information, thus providing guidance and constraints for engine design. Attached Figure Description

[0031] Figure 1 This is a flowchart of a method for estimating aircraft engine thrust based on flight parameters according to the present invention. Detailed Implementation

[0032] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings, so as to provide a better understanding of the concept of the present invention, the technical problem solved, the technical features constituting the technical solution, and the technical effects brought about. However, it should be noted that the description of these embodiments is illustrative and does not constitute a specific limitation of the present invention.

[0033] The design concept of this application is as follows: An aircraft's complete takeoff and landing is not a steady flight, and calculating the relevant solutions for unsteady flight paths is extremely difficult. This method employs the finite element method, dividing the complete flight path of a single takeoff and landing into several small segments. Within each segment, the aircraft can be approximated as performing steady flight. Multiple calculations are performed using massive flight parameter data to solve for the aircraft's engine thrust by writing the differential equation of the aircraft's center of mass dynamics in the trajectory coordinate system for each segment. The estimated engine thrust values ​​under various flight conditions are recorded and plotted as the engine thrust demand curve for a single takeoff and landing. This application is based on the flight parameters of the current flight segment: altitude H... i Atmospheric density ρ i Velocity v in the track coordinate system i Angle of attack αi Pitch angle Sideslip angle β i Roll angle γ i And the aircraft's fuel capacity (m) fi Combined with the input aircraft type information: Aircraft empty mass m e Wing area S, effective aspect ratio λ yx Engine mounting angle Wing angle of attack α0 and elevator deflection angle The slope of the lift line of the entire aircraft at that time Solve for the design data of the aircraft's current flight path segment: drag coefficient (C) x ) i and lift coefficient C yi Subsequently, based on mission information, the aircraft mass m within the current flight path segment is determined. i Find the aircraft drag Q within the current flight path segment. i Then, based on the flight path coordinate system, the following equations of motion for the aircraft's center of mass are written. Find the aircraft drag P for the current flight path segment. i Finally, calculate the aircraft drag P for all flight segments. i And plot the thrust demand curve.

[0034] When the flight path segmentation is sufficiently reasonable and the amount of flight parameter data is large and accurate enough, the obtained aircraft engine thrust estimate will be closer to the actual thrust value. This application uses the flight parameters of a certain takeoff and landing of an aircraft as the research object to estimate the aircraft engine thrust. During the estimation process, aircraft type information and mission information are required as key inputs for the aircraft engine thrust estimation process.

[0035] Specifically as follows:

[0036] This application provides a method for estimating aircraft engine thrust based on flight parameters, the method comprising the following steps:

[0037] S100, the complete flight path of a single takeoff and landing of an aircraft is divided into I segments, where i represents the i-th segment in I, 1≤i≤I, i∈[1,I].

[0038] It should be understood that the more segments the complete flight path of an aircraft during a single takeoff and landing is divided into, the higher the final calculated engine thrust value P will be. i The more segments a curve has, the more accurate the engine thrust demand curve will be; however, the more segments a curve has, the more computational work will be involved, leading to reduced computational efficiency. Therefore, those skilled in the art should, based on the actual situation, and in combination with the computational workload and the accuracy of the engine thrust demand curve, reasonably divide the complete flight path of a single takeoff and landing of an aircraft.

[0039] S200, calculate the engine thrust value P for each flight segment. i Once the complete flight path of the aircraft is defined, it is necessary to calculate the engine thrust value for each flight path segment. Specifically, step S200 is performed according to the following steps:

[0040] S201, Read the flight parameters of the i-th segment of the trajectory and obtain the altitude H of the i-th segment of the trajectory. i Atmospheric density ρ i Velocity v in the track coordinate system i Angle of attack α i Pitch angle Sideslip angle β i Roll angle γ i And the aircraft's fuel capacity (m) fi This application takes the flight parameters of a certain takeoff and landing of an aircraft as the research object, and the flight parameters can be directly read as research input.

[0041] S202, the aircraft model to be studied is specified, and the following aircraft information is determined: Aircraft empty mass (m) e Wing area S, effective aspect ratio λ yx Engine mounting angle Wing angle of attack α0 and elevator deflection angle The slope of the lift line of the entire aircraft at that time This step requires the user to determine the aircraft type to which the flight parameters for this study belong and the aforementioned parameters for that aircraft type.

[0042] S203, Determine mission information: Determine the aircraft's effective payload (m) p Unloading quality m′ i Find the mass m of the aircraft on the i-th segment of the trajectory. i .

[0043] S204, Calculate the aircraft drag Q for the i-th segment of the trajectory. i The aircraft drag Q is calculated based on the flight parameters read in step S201 and the aircraft type parameters determined in step S202. i :

[0044] (C x ) i Let be the drag coefficient of the i-th segment of the trajectory;

[0045] Among them (C) x ) i =(C x0 ) Hi +AC yi 2 (C) x0 ) Hi Let A be the zero-lift drag coefficient for the i-th segment of the trajectory, and C be the lift-induced drag factor. yiLet be the lift coefficient of the i-th segment of the trajectory.

[0046] S205, Calculate the estimated engine thrust P for the i-th segment of the trajectory. i When the aircraft drag Q of the i-th segment of the trajectory is calculated... i And determine the aircraft mass m of the i-th segment of the trajectory. i Then, the engine thrust value P for the i-th segment of the trajectory can be calculated. i :

[0047] Where θ i Let be the track inclination angle of the i-th segment of the track.

[0048] Engine thrust estimate P i The calculation formula is derived from the differential equation of the aircraft's center of mass dynamics in the track coordinate system. It is derived that...

[0049] S300 records the estimated thrust P of the aircraft engine for the i-th segment of the flight path. i And the current aircraft status information, the aircraft status information is H i v i α i β i , m i .

[0050] Aircraft state information refers to information that represents the state of the aircraft in the i-th segment of the flight path, including H. i v i α i β i , m i Those skilled in the art should understand that these six status information are recorded together to represent the complete flight status. Recording only one or a few of them cannot fully express the flight status and is not conducive to subsequent work such as aircraft engine thrust analysis.

[0051] Traditional methods for calculating aircraft engine thrust are insufficient to provide guidance and constraints for engine design based on flight parameters and mission requirements. In contrast, the aircraft engine thrust estimation method presented in this application takes into account flight parameters during flight, including aircraft type and mission information, and incorporates the finite element method to estimate aircraft engine thrust.

[0052] Compared to traditional data-based thrust estimation, which relies on a large amount of flight parameters and engine ground test data to obtain the aircraft engine thrust spectrum based on statistical laws, the aircraft engine thrust estimation formula derived in this application based on physical basis formulas has more reliable physical meaning and physical constraints. The resulting aircraft engine thrust spectrum is less distorted by data sampling errors, and its trends and characteristics are more in line with real-world laws. It has more guiding significance and predictive value, and can provide strong theoretical support for the prediction of aircraft engine thrust spectrum.

[0053] Among them, the lift coefficient C of the i-th segment of the trajectory in step S204 yi The formula for calculation is:

[0054] Among them, (α) i -α0) is the effective angle of attack.

[0055] The zero-lift drag coefficient (C) of the i-th segment of the trajectory x0 ) Hi The formula for calculation is:

[0056] (C x0 ) Hi =(C x0 ) H＝5 +ΔC x0,Hi , of which (C x0 ) H＝5 ΔC is the reference drag coefficient. x0,Hi Let ΔC be the altitude correction amount for the i-th segment of the trajectory. x0,Hi and zero-lift drag coefficient (C x0 ) H＝5 This can be found by consulting the table of zero-lift drag coefficient height correction.

[0057] In step S204, the lift-induced drag factor A, also known as the polar curve curvature coefficient, is calculated as follows:

[0058] Where π is the ratio of a circle's diameter to its circumference.

[0059] The aircraft mass m of the i-th segment of the trajectory in step S203 i The formula for calculation is:

[0060] m i =m e +m p +m fi -m′ i , where m p Let m be the aircraft's payload. The aircraft's payload remains constant throughout takeoff and landing. fi The fuel load of the aircraft on the i-th segment of the flight path can be obtained by reading data recorded from the aircraft's sensors.e The empty weight of the aircraft is determined through step S202, which clarifies the aircraft model under study. i Let m be the unloaded mass of the i-th segment of the flight path. The aircraft continuously consumes fuel during flight, and unloading may occur during flight; therefore, the aircraft mass m for each segment of the flight path is... i There are discrepancies, and it is necessary to determine the aircraft mass m for each flight segment. i .

[0061] In step S205, the track inclination angle θ of the i-th segment of the track i The formula for calculation is:

[0062] In step S201, the flight parameters of the i-th segment of the trajectory are read, thus obtaining the angle of attack α of the i-th segment of the trajectory. i Pitch angle Sideslip angle β i Roll angle γ i Therefore, step S205 incorporates the flight parameters read in S201 into the aforementioned track inclination angle θ. i The inclination angle of the track can be calculated using the formula.

[0063] Preferably, to ensure calculation accuracy, a data preprocessing step following step S201 is included. This preprocessing step removes outliers from the flight parameters obtained in step S201 and smooths and filters the remaining data. Specifically: 1. In cases of missing parameters, linear interpolation or substitution of previous values ​​for subsequent values ​​is used to fill in the missing values; 2. Distorted data or outliers are removed; 3. Through sliding smoothing filtering, data points within a fixed interval are extracted, and a polynomial is used to fit each data point within the interval, ensuring that the fitted data has the smallest error compared to the original data. Essentially, this is a weighted average of the data points before and after that data point.

[0064] Preferably, it also includes step S400 after step S300, which determines the engine thrust value P for each flight segment. i This involves plotting the engine thrust demand curve for a single takeoff and landing. Plotting this curve facilitates data observation and analysis for researchers. Those skilled in the art should understand that the horizontal axis of the engine thrust demand curve is typically time, and the vertical axis represents the engine thrust value P. i Of course, those skilled in the art can represent the horizontal axis with other data according to the actual situation, and this application does not impose any restrictions.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for estimating aircraft engine thrust based on flight parameters, characterized in that, Includes the following steps: S100, the complete flight path of a single takeoff and landing of an aircraft is divided into I segments, where i represents the i-th segment in I segment, 1≤i≤I, i∈[1,I]; S200, calculate the engine thrust value P for each flight segment. i ; S201, Read the flight parameters of the i-th segment of the trajectory: Obtain the altitude H of the i-th segment of the trajectory. i Atmospheric density ρ i Velocity v in the track coordinate system i Angle of attack α i Pitch angle Sideslip angle β i Roll angle γ i And the aircraft's fuel capacity (m) fi ; S202, specify the aircraft model to be studied, and determine the following aircraft information: Aircraft empty mass (m) e Wing area S, effective aspect ratio λ yx Engine mounting angle Wing angle of attack α0 and elevator deflection angle The slope of the lift line of the entire aircraft at that time S203, Determine mission information: Determine the aircraft's effective payload (m) p Unloading quality m′ i Find the mass m of the aircraft on the i-th segment of the trajectory. i ; S204, Calculate the aircraft drag Q for the i-th segment of the trajectory. i : (C x ) i Let be the drag coefficient of the i-th segment of the trajectory; Among them (C) x ) i =(C x0 ) Hi +AC yi 2 , (C x0 ) Hi Let A be the zero-lift drag coefficient for the i-th segment of the trajectory, and C be the lift-induced drag factor. yi Let be the lift coefficient of the i-th segment of the trajectory; S205, Calculate the estimated engine thrust P for the i-th segment of the trajectory. i : Where θ i Let be the track inclination angle of the i-th segment of the track; S300 records the estimated thrust P of the aircraft engine for the i-th segment of the flight path. i And the current aircraft status information, the aircraft status information is H i v i α i β i , m i .

2. The method for estimating aircraft engine thrust based on flight parameters according to claim 1, characterized in that, In step S204, the lift coefficient C of the i-th segment of the trajectory yi The formula for calculation is: Among them, (α) i -α0) is the effective angle of attack.

3. The method for estimating aircraft engine thrust based on flight parameters according to claim 1, characterized in that, In step S204, the zero-lift drag coefficient (C) of the i-th segment of the trajectory x0 ) Hi The formula for calculation is: (C x0 ) Hi =(C x0 ) H＝5 +ΔC x0,Hi , of which (C x0 ) H＝5 ΔC is the reference drag coefficient. x0,Hi This is the altitude correction amount for the i-th segment of the trajectory.

4. The method for estimating aircraft engine thrust based on flight parameters according to claim 1, characterized in that, In step S204, the formula for calculating the lift-induced drag factor A is: Where π is the ratio of a circle's diameter to its circumference.

5. The method for estimating aircraft engine thrust based on flight parameters according to claim 1, characterized in that, In step S203, the aircraft mass m of the i-th segment of the trajectory i The formula for calculation is: m i =m e +m p +m fi -m i ′。 6. The method for estimating aircraft engine thrust based on flight parameters according to claim 1, characterized in that, In step S205, the track inclination angle θ of the i-th segment of the track i The formula for calculation is:

7. A method for estimating aircraft engine thrust based on flight parameters according to any one of claims 1 to 6, characterized in that: It also includes a data preprocessing step following S201, which removes outliers from the flight parameters obtained in step S201 and smooths and filters the remaining data.

8. A method for estimating aircraft engine thrust based on flight parameters according to any one of claims 1 to 6, characterized in that: It also includes step S400, which follows step S300, based on the engine thrust value P for each flight segment. i Plot the thrust demand curve for an aircraft engine during a single takeoff and landing.

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