1. A method for calculating and generating an aircraft cruise equal-minute oil consumption envelope comprehensive chart is characterized by comprising the following steps of: the method comprises the following steps:

establishing a cruise flight dynamics equation, solving cruise minute oil consumption at each altitude and speed state point by two-dimensional cyclic calculation of cruise altitude and cruise speed, and performing two-dimensional cyclic calculation by taking different cruise altitude points and different speed points as initial conditions according to the flight envelope range of the airplane to obtain a cruise minute oil consumption database in the whole flight envelope range;

and step two, generating an equal-minute oil consumption coil diagram according to the cruise minute oil consumption database of the airplane.

2. The aircraft cruise equal minute fuel consumption envelope complex chart calculation and generation method of claim 1, wherein: in the first step, acquiring the cruise minute fuel consumption data of the airplane comprises the following steps:

(1) establishing an airplane cruise horizontal flight kinetic equation based on the overall parameter data, the pneumatic data and the engine data of the airplane and according to the flight kinetic characteristics of cruise flight;

(2) according to the given initial parameter conditions: the method comprises the following steps of (1) circularly and iteratively calculating a cruise level flight kinetic equation according to the mass, the flight height and the flight speed of the airplane, and calculating the thrust required by the level flight of the airplane under the condition;

(3) according to the engine data of the airplane, the engine state of the airplane is obtained through interpolation calculation of the thrust data, and the cruise minute oil consumption data of the airplane are calculated through the engine state, the speed and the ambient temperature.

3. The aircraft cruise equal minute fuel consumption envelope complex chart calculation and generation method of claim 1, wherein: in the second step, a minute oil consumption range is combed out according to an airplane cruise minute oil consumption database; and performing interpolation calculation through the altitude points or the speed points to obtain the distribution positions of the target minute oil consumption in different altitude and speed ranges, and then drawing the same minute oil consumption data points in the flight envelope range into a cartographic chart.

4. The aircraft cruise equal minute fuel consumption envelope map calculation and generation method of claim 2, wherein: the aircraft cruise flight dynamics equation is as follows:

P cos(α+φ_p)-D＝0 ①

L+P sin(α+φ_p)-G＝0 ②

C_y＝L/(0.5ρV²S) ③

D＝0.5C_xρV²S ④

in the above formula, P is the engine thrust force on the aircraft; d is the aerodynamic resistance borne by the aircraft; l is the aerodynamic lift force borne by the aircraft; g is the gravity of the airplane; alpha is the attack angle of the airplane, namely the included angle between the speed direction of the airplane and the horizontal line of the airplane body; phi is a_pThe included angle between the thrust line of the engine and the horizontal line of the airplane body is shown; c. C_yIs the aircraft lift coefficient; c. C_xIs the aircraft drag coefficient; ρ is the atmospheric density; v is the flight speed, and S is the reference area of the airplane;

5. the aircraft cruise equal minute fuel consumption envelope map calculation and generation method of claim 2, wherein: in (1), the aerodynamic data consists of an angle of attack, a lift coefficient, and a drag coefficient.

Background

When an aircraft is performing a long-endurance cruise flight mission, the pilot needs to determine the fuel consumption per minute or per hour at a given cruise altitude, cruise speed, and then estimate the amount of fuel that may be consumed by the cruise flight mission based on the time the cruise flight mission is in flight. Currently, aircraft design departments typically calculate optimal cruise minute fuel consumption at a given altitude based on the capabilities of the aircraft. However, depending on the flight mission or change in mission, the pilot often needs to acquire minute fuel consumption at other altitudes and speeds for planning other cruise flight missions. Modern aircraft have very broad flight envelope, flight altitude can range from sea level to ten thousand meters high altitude, and flight speed can range from 200 km/h to more than 1000 km/h. If the minute oil consumption at each altitude and speed is to be acquired, the number of the calculated state points is very large, and the large number of data points is unfavorable for the search and use of the pilot, so that a comprehensive display graph of the minute oil consumption in the full envelope range of the airplane needs to be generated on the basis of acquiring the minute oil consumption databases at the state points of different altitudes and speeds, so that the pilot can conveniently and intuitively search the minute oil consumption data at each altitude and speed. At present, no relevant data of the cruise flight minute fuel consumption line drawing method and relevant research in the aspect are found from published literature data.

Disclosure of Invention

The invention provides a method for calculating and generating a comprehensive chart of minute oil consumption envelope of cruise and the like of an airplane.

In order to achieve the purpose, the invention adopts the following technical scheme: a method for calculating and generating an aircraft cruise equal-minute oil consumption envelope comprehensive chart is characterized by comprising the following steps of: the method comprises the following steps:

establishing a cruise flight dynamics equation, solving cruise minute oil consumption at each altitude and speed state point by two-dimensional cyclic calculation of cruise altitude and cruise speed, and performing two-dimensional cyclic calculation by taking different cruise altitude points and different speed points as initial conditions according to the flight envelope range of the airplane to obtain a cruise minute oil consumption database in the whole flight envelope range;

and step two, generating an equal-minute oil consumption coil diagram according to the cruise minute oil consumption database of the airplane.

Preferably, in step one, acquiring the cruise minute fuel consumption data of the airplane comprises the following steps:

(1) establishing an airplane cruise horizontal flight kinetic equation based on the overall parameter data, the pneumatic data and the engine data of the airplane and according to the flight kinetic characteristics of cruise flight;

(2) according to the given initial parameter conditions: the method comprises the following steps of (1) circularly and iteratively calculating a cruise level flight kinetic equation according to the mass, the flight height and the flight speed of the airplane, and calculating the thrust required by the level flight of the airplane under the condition;

(3) according to the engine data of the airplane, the engine state of the airplane is obtained through interpolation calculation of the thrust data, and the cruise minute oil consumption data of the airplane are calculated through the engine state, the speed and the ambient temperature.

Preferably, in the second step, the minute oil consumption range is combed out according to the cruise minute oil consumption database of the airplane; and performing interpolation calculation through the altitude points or the speed points to obtain the distribution positions of the target minute oil consumption in different altitude and speed ranges, and then drawing the same minute oil consumption data points in the flight envelope range into a cartographic chart.

Preferably, the aircraft cruise flight dynamics equation is:

P cos(α+φ_p)-D＝0 ①

L+P sin(α+φ_p)-G＝0 ②

C_y＝L/(0.5ρV²S) ③

D＝0.5C_xρV²S ④

in the above formula, P is the engine thrust force on the aircraft; d is the aerodynamic resistance borne by the aircraft; l is the aerodynamic lift force borne by the aircraft; g is the gravity of the airplane; alpha is the attack angle of the airplane, namely the included angle between the speed direction of the airplane and the horizontal line of the airplane body; phi is a_pThe included angle between the thrust line of the engine and the horizontal line of the airplane body is shown; c. C_yIs the aircraft lift coefficient; c. C_xIs the aircraft drag coefficient; ρ is the atmospheric density; v is the flight speed, and S is the reference area of the airplane;

preferably, in (1), the aerodynamic data consists of an angle of attack, a lift coefficient, and a drag coefficient.

Compared with the prior art, the invention has the following advantages: by calculating the minute oil consumption data in the flight envelope range of the airplane and generating a comprehensive display graph convenient to search, the pilot can more visually search the minute oil consumption data at each altitude and speed, and the pilot can more quickly plan the cruise flight task.

Detailed Description

The invention is described in further detail below: a method for calculating and generating an aircraft cruise hourly fuel consumption envelope comprehensive chart mainly comprises two parts:

1) establishing a cruise flight dynamics equation, and solving cruise minute oil consumption at each altitude and speed state point by two-dimensional cyclic calculation of cruise altitude and cruise speed;

firstly, establishing an aircraft cruise level flight kinetic equation based on the general parameter data, pneumatic data, engine data and the like of an aircraft according to the flight kinetic characteristics of cruise flight;

secondly, according to given initial parameter conditions, such as the mass, the flying height and the flying speed of the airplane, circularly and iteratively calculating to solve a cruise horizontal flight equation of motion, and solving the thrust required by the horizontal flight of the airplane under the conditions;

finally, according to the engine data of the airplane, the engine state of the airplane is obtained through interpolation calculation of the thrust data, and then the fuel consumption data of the airplane is calculated through the engine state, the speed, the ambient temperature and the like;

in the calculation process, according to the flight envelope range of the airplane, taking different cruise altitude points and different speed points as initial conditions to perform two-dimensional cyclic calculation, and finally obtaining a cruise minute oil consumption database in the whole flight envelope range;

2) generating an equal-minute oil consumption coil diagram according to an airplane cruise minute oil consumption database;

combing out a minute oil consumption range according to an airplane cruising minute oil consumption database; performing interpolation calculation through the altitude points or the speed points to obtain the distribution positions of the target minute oil consumption in different altitude and speed ranges; and finally, drawing the oil consumption data points in the same minute within the flight envelope into a cartographic chart.

The specific steps of the embodiment are as follows:

(1) firstly, establishing a cruise flight dynamics equation, wherein when the aircraft flies at an equal speed, the track angle of the aircraft is zero, the thrust of an engine of the aircraft mainly balances the aerodynamic drag borne by the aircraft, and the aerodynamic lift of the aircraft mainly balances the gravity of the aircraft, so that the cruise flight dynamics equation of the aircraft is as follows:

P cos(α+φ_p)-D＝0 ①

L+P sin(α+φ_p)-G＝0 ②

in the above formula, P is the engine thrust force on the aircraft; d is the aerodynamic resistance borne by the aircraft; l is the aerodynamic lift force borne by the aircraft; g is the gravity of the airplane; alpha is the attack angle of the airplane, namely the included angle between the speed direction of the airplane and the horizontal line of the airplane body; phi is a_pThe included angle between the thrust line of the engine and the horizontal line of the airplane body is shown;

(2) the above equation is solved according to the given initial conditions. The speed, altitude and gravity of the aircraft are known conditions, assuming initial conditionsThe lift force of the airplane is equal to the gravity in the state, and the initial lift coefficient c of the airplane can be obtained_ySee formula (iii) below;

wherein rho is the atmospheric density and can be obtained from the height; v is the flight speed, and S is the reference area of the airplane;

C_y＝L/(0.5ρV²S) ③

the aerodynamic data of the airplane consists of an attack angle, a lift coefficient and a resistance coefficient, and the attack angle has a corresponding relation with the lift coefficient and the resistance coefficient. Therefore, the initial attack angle and the drag coefficient of the airplane can be calculated by interpolation of the lift coefficient obtained by the formula III, so that the aerodynamic drag borne by the airplane can be obtained, and the aerodynamic drag can be obtained by the formula IV_xIs the aircraft drag coefficient; the resistance is brought into the formula I to obtain the thrust of an engine required by the airplane, and then the lift force of the airplane can be obtained by the formula II;

D＝0.5C_xρV²S ④

the thrust required by the flat flight at the initial height and speed can be obtained through multiple iterative computations in the solving process; the engine data of the airplane consists of data such as speed, altitude, engine state, thrust, oil consumption per unit time and the like, the obtained thrust is taken into an airplane engine database to carry out interpolation calculation so as to obtain the state of the airplane engine, and the minute oil consumption of the airplane can be obtained by the interpolation calculation of the speed and the engine state;

(3) selecting different heights and speeds within the range of the flight envelope of the airplane, and circularly performing the minute oil consumption calculation process in the step (2), so as to obtain a minute oil consumption database within the range of the full envelope of the airplane, as shown in table 1;

table 1: schematic data table of airplane minute fuel consumption database

The data volume is determined by the number of the selected altitude and speed points, and the minute oil consumption data distribution of the aircraft under the typical flight weight within the range of 0-10000 m of altitude and 0.3-0.75 of Mach number is shown in Table 1. As can be seen from table 1, the same minute fuel consumption distribution at different altitudes and speed ranges, such as mach number 0.35, the minute fuel consumption of 26 (kg/min) is distributed at the altitude of 3000 m and the altitude of 5000 m, and the altitude and speed position of the 26 (kg/min) distribution can be obtained by interpolation calculation in the altitude and speed range. Taking the minute oil consumption 25 (kilogram/minute) as an example, when the height is 7000 meters, the minute oil consumption can be calculated to be distributed at a certain position between Mach numbers 0.35-0.4 and 0.6-0.65 respectively, the specific position is obtained by linear interpolation calculation, similarly, when the Mach number is 0.45, the minute oil consumption can be distributed between heights 5000-6000 meters, and by analogy, at different heights or speed ranges, the distribution position of the height and the speed of the minute oil consumption 25 (kilogram/minute) in a flight envelope can be calculated by taking the minute oil consumption 25 (kilogram/minute) as an interpolation point, and then an equal 25 (kilogram/minute) minute oil consumption envelope curve diagram can be drawn, and other equal minute oil consumption envelope curves can be generated by adopting the same method, as shown in FIG. 1;

FIG. 1: air plane minute-equal oil consumption envelope diagram

It should be noted that the accuracy of the minute-minute fuel consumption histogram is determined by the degree of density of the height and speed state points set by calculation, and it is obvious that the denser the state points are, the more accurate the position of the target minute fuel consumption is, and the smoother the curve of the minute-minute fuel consumption histogram is, but the calculation amount is larger.