A simulation method for double-wake vortex encounter effects in flight simulators

Abstract

The present invention belongs to the field of flight simulators and simulation technology, and specifically relates to a dual-tail vortex encounter effect simulation method for flight simulators, aiming to solve the problem of being unable to meet the real-time and high-precision simulation requirements of flight training platforms. The present invention calculates the tail vortex index by obtaining relevant parameters of the preceding aircraft operation, divides the wake dissipation stage and establishes a tail vortex strength model, determines the vortex position to calculate the induced velocity, compares the tail vortex strength to determine the relative distance between the front and rear aircraft, and selects different methods to calculate the incremental velocity and angular velocity and integrate them to obtain the aircraft state parameters. The new incremental aerodynamic coefficient can be calculated based on the aircraft state parameters, and the aircraft state obtained based on the new incremental aerodynamic coefficient is then iterated. The calculated aircraft state tends to be accurate after coefficient iteration, which reduces the average running time. The present invention effectively improves the simulation accuracy and real-time performance, and can fully meet the relevant requirements of the flight training platform.

Description

Technical Field

[0001] The invention belongs to the field of flight simulators and simulation technology, and particularly relates to a double-tail vortex encounter effect simulation method for a flight simulator. Background Art

[0002] Aircraft wake is a byproduct of aircraft lift. When a following aircraft enters the wake area of ​​the leading aircraft, especially for small aircraft such as the ARJ21 and other series, the following aircraft may experience dangerous situations such as rolling and turbulence, especially when the wake effect level generated by the leading aircraft is higher than the response capability of the following aircraft.

[0003] Wake encounter effect simulation technology provides important support for flight safety and air traffic management by simulating the generation and evolution of wake turbulence and its impact on following aircraft. Current methods mainly include numerical simulation methods and wake attenuation simulation models. Numerical simulation methods offer high modeling accuracy but poor real-time performance, making them unsuitable for real-time simulation operations on flight training platforms. Wake attenuation models can quickly assess the effects of a following aircraft encountering a wake turbulence, but the models are simplified and do not consider aerodynamic interference mechanisms. Existing models struggle to accurately calculate the incremental aerodynamic forces caused by the wake of the leading aircraft, and the simulated aircraft wake response states struggle to approximate real-world scenarios. Summary of the Invention

[0004] In order to solve the above-mentioned problems in the prior art, namely, the numerical simulation methods in the existing wake encounter effect simulation technology have poor real-time performance, the wake attenuation model does not consider the aerodynamic interference mechanism, resulting in inaccurate incremental aerodynamic calculation, and the simulated aircraft wake response state is difficult to approach the real state, which cannot meet the real-time and high-precision simulation requirements of the flight training platform. In a first aspect, the present invention proposes a double wake vortex encounter effect simulation method for a flight simulator, which includes the following steps:

[0005] S1, based on the operation-related parameters of the preceding aircraft in the flight simulator training scenario, obtains the wake vortex parameters through the pre-built wake vortex model;

[0006] S2, according to the stage of wake dissipation of the preceding aircraft, establishing a wake vortex strength model for each stage based on the wake vortex parameters and the dimensionless buoyancy frequency, and obtaining a wake vortex strength value for the corresponding stage;

[0007] S3, determining the vortex position; calculating the distance from any point on the subsequent aircraft encountering the wake vortex to the vortex position, and calculating the induced velocity of a single vortex at any point based on the distance;

[0008] S4, calculating a current tail vortex intensity ratio based on the tail vortex intensity value and the tail vortex initial circulation, and comparing the ratio with a critical value to obtain a relative distance between the preceding aircraft and the succeeding aircraft;

[0009] S5. Calculate the incremental velocity and incremental angular velocity of the entire aircraft in different ways based on the relative distance between the preceding aircraft and the succeeding aircraft; integrate the incremental velocity and incremental angular velocity to obtain aircraft state parameters, where the aircraft state parameters include the aircraft's velocity, position, attitude angular velocity, and attitude angle.

[0010] In some preferred embodiments, the operation-related parameters include the mass, wingspan, true airspeed, normal overload and air density of the preceding aircraft; the trailing vortex parameters include the trailing vortex initial circulation, vortex core radius, characteristic time and trailing vortex characteristic speed;

[0011] The initial circulation of the tail vortex:

[0012] ;

[0013] ;

[0014] in, is the initial vortex circulation; is the normal overload of the aircraft; is the mass of the preceding aircraft; is the acceleration due to gravity; is the air density; is the true airspeed of the preceding aircraft; is the initial vortex distance;

[0015] Vortex core radius:

[0016] ;

[0017] is the vortex core radius; is the aircraft wingspan; is the initial vortex core radius;

[0018] Trailing vortex characteristic velocity:

[0019] ;

[0020] Feature time:

[0021] ;

[0022] in, is the characteristic time; Characteristic velocity of the trailing vortex.

[0023] In some preferred embodiments, the stages of wake turbulence dissipation of the preceding aircraft include a diffusion stage and a rapid decay stage;

[0024] The tail vortex strength model of the diffusion stage is: ;

[0025] The tail vortex strength model in the rapid decay stage is: ;

[0026] in, is the trailing vortex intensity value after the diffusion stage decays; is the dimensionless buoyancy frequency; is the duration of the wake vortex effect; is the duration of the diffusion phase.

[0027] In some preferred embodiments, the eddy current position is determined by:

[0028] Select a cross section perpendicular to the wake field, take the midpoint of the line connecting the left and right vortex cores as the origin, establish a coordinate system with the x-axis along the line and the y-axis perpendicular to the line;

[0029] The left and right vortices are located at (0, B / 2) and (0, −B / 2) in the coordinate system respectively.

[0030] In some preferred embodiments, the induced velocity of the single vortex at any point is obtained by:

[0031] Based on the positions of the left and right vortices, calculate the distance from any point on the aircraft encountering the wake vortex to the vortex position:

[0032] ;

[0033] Calculate the induced velocity of a single vortex at any point based on the distance:

[0034] ;

[0035] in, is the distance from any point of the subsequent aircraft to the origin; is the strength of the wake vortex encountered by the subsequent aircraft; x and y are the coordinates of any point on the aircraft.

[0036] In some preferred embodiments, the relative distance between the preceding aircraft and the succeeding aircraft is obtained by:

[0037] Calculate the ratio of the current trailing vortex strength: ;

[0038] The current tail vortex strength ratio is compared with the critical value to obtain the relative distance between the preceding aircraft and the succeeding aircraft:

[0039] When D is less than or equal to the critical value, it is determined that the relative distance between the preceding aircraft and the succeeding aircraft is far; otherwise, it is determined that the relative distance between the preceding aircraft and the succeeding aircraft is close.

[0040] In some preferred embodiments, different methods are selected to calculate the incremental velocity and incremental angular velocity of the entire aircraft according to the relative distance between the preceding aircraft and the succeeding aircraft. The method is:

[0041] If the relative distance between the preceding aircraft and the succeeding aircraft is relatively close, the succeeding aircraft is split into predetermined load-bearing components and the induced velocity of each load-bearing component is calculated. An incremental aerodynamic force is calculated based on the induced velocity. The incremental velocity and incremental angular velocity of the corresponding load-bearing component are obtained by integration, and the incremental velocity and incremental angular velocity of each load-bearing component are added together to obtain the incremental velocity and incremental angular velocity of the entire aircraft.

[0042] If the relative distance between the preceding aircraft and the succeeding aircraft is relatively far, the incremental aerodynamic force is calculated based on the induced velocity, and the incremental velocity and incremental angular velocity of the entire aircraft are obtained by applying the incremental aerodynamic force and control parameters to the six-degree-of-freedom equation;

[0043] The incremental speeds are u, v, w; the incremental angular speeds are p, q, r.

[0044] In some preferred embodiments, the incremental aerodynamic force includes lift, drag, side force, rolling moment, pitching moment, and heading moment; the calculation method of each parameter in the incremental aerodynamic force is:

[0045] Lift: ;

[0046] resistance: ;

[0047] Lateral force: ;

[0048] Rolling moment: ;

[0049] Pitching moment: ;

[0050] Heading moment: ;

[0051] in, is the induced velocity; is the current air density; is the projected area of ​​the entire aircraft; is the wing span; is the average aerodynamic chord length of the wing; is the lift coefficient; is the drag coefficient; is the lateral force coefficient; is the rolling moment coefficient; is the pitching moment coefficient; is the yaw moment coefficient.

[0052] In some preferred embodiments, the six-degree-of-freedom equation is:

[0053] ;

[0054] ;

[0055] ;

[0056] ;

[0057] ;

[0058] ;

[0059] in, is the gross weight of the aircraft; They are the incremental velocity change rates along the xyz axes; It is thrust; is the angle of attack; is the sideslip angle; is the pitch angle; is the roll angle; are the moments of inertia around the xyz axes; are the incremental angular velocities around the x, y, and z axes respectively; these are control parameters.

[0060] Beneficial effects of the present invention:

[0061] The simulation module / platform containing this technology can realize the layout and application of eddy current effects on flight simulators, enriching training scenarios;

[0062] Based on the takeoff time and distance of the subsequent aircraft, the wake effects encountered by the aircraft are modeled and analyzed. The aerodynamic model and wake model are integrated to ultimately obtain the incremental aerodynamic force and aircraft state caused by the wake of the preceding aircraft. The new incremental aerodynamic coefficients can be calculated using the difference algorithm based on the aircraft state parameters. The aircraft state obtained based on the new incremental aerodynamic coefficients tends to be consistent with the increase in the number of coefficient iterations. The two results are within the ±5% error band, which improves the pilot's emergency response capabilities in this scenario, ensures flight safety, and thus enhances training effectiveness.

[0063] For comparison, the runtime of simulation modules incorporating this technology is shown below: On a 100Hz simulation platform, where the sum of the operating cycles of all aircraft modules is less than 10ms, the average runtime of the eddy current simulation is approximately 200μs (30s per test cycle, with the average of six cycles taken), improving real-time performance. Numerical simulation, on the other hand, would be much more time-consuming. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0065] Figure 1 The present invention is a flowchart of the steps of a method for simulating a double-tail vortex encounter effect for a flight simulator. DETAILED DESCRIPTION

[0066] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the relevant invention are shown in the accompanying drawings.

[0067] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0068] In order to more clearly illustrate the double vortex encounter effect simulation method for a flight simulator of the present invention, the following is combined with Figure 1 Each step in the embodiment of the present invention is described in detail.

[0069] The present invention proposes a method for simulating the double-tail vortex encounter effect for a flight simulator, see Figure 1 , the method comprises the following steps:

[0070] S1, based on the operation-related parameters of the preceding aircraft in the flight simulator training scenario, obtains the wake vortex parameters through the pre-built wake vortex model;

[0071] In this embodiment, the operation-related parameters include the mass, wingspan, true airspeed, normal overload, and air density of the preceding aircraft;

[0072] The tail vortex parameters include the initial vortex circulation, initial vortex spacing, vortex core radius, characteristic time, and tail vortex characteristic speed;

[0073] The initial circulation of the tail vortex:

[0074] ;

[0075] ;

[0076] in, is the initial vortex circulation; is the normal overload of the aircraft; is the mass of the preceding aircraft; is the acceleration due to gravity; is the air density; is the true airspeed of the preceding aircraft; is the initial vortex distance;

[0077] Vortex core radius:

[0078] ;

[0079] in, is the vortex core radius; is the aircraft wingspan; is the initial vortex core radius. The simulation is performed under the condition that the strongest torque is generated in the tail vortex velocity field. The vortex core radius is approximately equal to the initial vortex core radius. ;

[0080] Trailing vortex characteristic velocity:

[0081] ;

[0082] Feature time:

[0083] ;

[0084] is the characteristic time; characteristic velocity of the trailing vortex;

[0085] S2, according to the stage of wake dissipation of the preceding aircraft, establishing a wake vortex strength model for each stage based on the wake vortex parameters and the dimensionless buoyancy frequency, and obtaining a wake vortex strength value for the corresponding stage;

[0086] In this embodiment, the stages of the wake dissipation of the preceding aircraft include a diffusion stage and a rapid decay stage;

[0087] The tail vortex intensity model of the diffusion stage (near-field vortex) is: ;

[0088] The tail vortex strength model in the rapid decay stage (far-field vortex) is: ;

[0089] in, is the trailing vortex intensity value after the diffusion stage decays; is the dimensionless buoyancy frequency; is the duration of the wake vortex effect; is the duration of the diffusion phase;

[0090] S3, determining the vortex position; calculating the distance from any point on the subsequent aircraft encountering the wake vortex to the vortex position, and calculating the induced velocity of a single vortex at any point based on the distance;

[0091] In this embodiment, the eddy current position is determined by:

[0092] Select a cross section perpendicular to the wake field, take the midpoint of the line connecting the left and right vortex cores as the origin, establish a coordinate system with the x-axis along the line and the y-axis perpendicular to the line;

[0093] The left and right vortices are located at (0, B / 2) and (0, −B / 2) in the coordinate system respectively;

[0094] The induced velocity of the single vortex at any point is obtained as follows:

[0095] Based on the positions of the left and right vortices, calculate the distance from any point on the aircraft encountering the wake vortex to the vortex position:

[0096] ;

[0097] Calculate the induced velocity of a single vortex at any point based on the distance:

[0098] ;

[0099] in, is the distance from any point of the subsequent aircraft to the origin; 、 Represent the distances of the right vortex and the left vortex respectively, and express the calculation formula of the distance from any point on the aircraft to the double vortex, which can be substituted into the induced speed formula to calculate the induced speed; is the strength of the wake turbulence of the preceding aircraft encountered by the following aircraft; x and y are the coordinates of any point on the aircraft;

[0100] It is explained here that, in the following text, when the relative distance between the preceding and succeeding aircraft is far, the succeeding aircraft is regarded as a point mass, and the induced velocity is calculated using a distance.

[0101] In the following text, when the relative distance between the preceding and succeeding aircraft is relatively close, the succeeding aircraft encounters an inhomogeneous velocity field, which causes different aircraft components to use different distances and calculate different induced velocities;

[0102] Note: The effect on the aircraft is reflected in the area parameter S in the calculation of aerodynamic forces / moments;

[0103] S4, calculating a current tail vortex intensity ratio based on the tail vortex intensity value and the tail vortex initial circulation, and comparing the ratio with a critical value to obtain a relative distance between the preceding aircraft and the succeeding aircraft;

[0104] In this embodiment, the geometric parameters, flight altitude, and current atmospheric parameters of the preceding aircraft all affect the attenuation strength of the wake vortex. When the wake vortex strength reaches a certain critical value, the induced velocities on the various components of the succeeding aircraft are approximately equal. Therefore, by determining whether the current wake vortex strength has reached the critical value, the calculation model is divided into two parts. The determination condition for the wake vortex strength is the ratio of the current wake vortex strengths;

[0105] The relative distance between the preceding aircraft and the succeeding aircraft is obtained by:

[0106] Calculate the ratio of the current trailing vortex strength: ;

[0107] The current tail vortex strength ratio is compared with the critical value to obtain the relative distance between the preceding aircraft and the succeeding aircraft:

[0108] When D is less than or equal to the critical value, it is determined that the relative distance between the preceding aircraft and the succeeding aircraft is relatively far; otherwise, it is determined that the relative distance between the preceding aircraft and the succeeding aircraft is relatively close; wherein the critical value is preferably 0.1;

[0109] S5, selecting different methods to calculate the incremental velocity and incremental angular velocity of the entire aircraft based on the relative distance between the preceding aircraft and the succeeding aircraft; integrating the incremental velocity and incremental angular velocity to obtain aircraft state parameters;

[0110] In this embodiment, different methods are selected to calculate the incremental velocity and incremental angular velocity of the entire aircraft according to the relative distance between the preceding aircraft and the succeeding aircraft. The method is as follows:

[0111] If the relative distance between the preceding aircraft and the succeeding aircraft is relatively close, the induced velocities encountered by different components of the succeeding aircraft are different due to the greater effect of the distance. Therefore, the succeeding aircraft is divided into the set load-bearing components (fuselage, engine, wing and horizontal tail) and the induced velocity of each load-bearing component is calculated. The incremental aerodynamic force is calculated based on the induced velocity, and the incremental velocity and incremental angular velocity of the corresponding load-bearing component are obtained by integration. Specifically, according to the current lift increment ΔF (the lift, drag and side force of the aerodynamic force are calculated as follows, and the increments of lift, drag and side force are obtained) and Newton's second law ΔF = mΔa, the corresponding incremental velocity can be obtained by integration; according to the current torque change ΔM (the rolling moment, pitching moment and heading moment of the aerodynamic force are calculated as follows, and the increments of rolling moment, pitching moment and heading moment are obtained) and the rotation law of rigid body ΔM = IΔα, which can be integrated to obtain the corresponding incremental angular velocity), and the incremental velocity and incremental angular velocity of each force-bearing component are superimposed to obtain the incremental velocity and incremental angular velocity of the entire aircraft (specifically, the incremental velocity and incremental angular velocity encountered by different components of the aircraft are linearly superimposed to obtain the incremental velocity u, v, w, and incremental angular velocity p, q, r of the entire aircraft);

[0112] If the relative distance between the preceding and succeeding aircraft is relatively far, the entire aircraft uses a single induced velocity, i.e., the induced velocity of the entire aircraft, which is calculated using a single distance. Therefore, the incremental aerodynamic force is calculated based on the induced velocity. The incremental aerodynamic force and control parameters are applied to the six-degree-of-freedom equation to obtain the incremental velocity and incremental angular velocity of the entire aircraft.

[0113] The incremental speeds are u, v, w; the incremental angular speeds are p, q, r;

[0114] It should be noted that the close-range and long-range calculations are two parallel calculation threads. Only one method can be selected for each calculation without conflict. There is no distinction between u, v, w; p, q, r.

[0115] As the distance increases, it will become a long-distance method, but the letters and meanings of the iteration parameters remain unchanged, and there is no need to distinguish the parameters;

[0116] The incremental aerodynamic force includes lift, drag, side force, rolling moment, pitching moment, and heading moment. The calculation method of each parameter in the incremental aerodynamic force is:

[0117] Lift: ;

[0118] resistance: ;

[0119] Lateral force: ;

[0120] Rolling moment: ;

[0121] Pitching moment: ;

[0122] Heading moment: ;

[0123] in, is the induced velocity; is the current air density; is the projected area of ​​the entire aircraft; is the wing span; is the average aerodynamic chord length of the wing; is the lift coefficient; is the drag coefficient; is the lateral force coefficient; is the rolling moment coefficient; is the pitching moment coefficient; is the yaw moment coefficient. The specific calculation process of each coefficient is as follows:

[0124] ;

[0125] ;

[0126] ;

[0127] ;

[0128] ;

[0129] Where, (Basic rigid-airplane) represents the influence of the basic rigid-airplane on each coefficient (in each coefficient, Specifically, it represents the influence of the basic rigid body aircraft on the lift coefficient, drag coefficient, side force coefficient, rolling moment coefficient, pitching moment coefficient, and yaw moment coefficient, specifically the influence increment, and the same applies to other parameters);

[0130] (change in stabilizer incidence and elevator deflection from zero degrees) represents the effect of horizontal stabilizer inclination and elevator deflection on each coefficient;

[0131] (ground effect) represents the influence of ground effect on the corresponding coefficient;

[0132] (airframe deformation resulting from static aeroelasticity and inertia relief) represents the effect of the elastic deformation of the fuselage on the corresponding coefficient

[0133] (airplane dynamics) represents the influence of aircraft dynamics on the corresponding coefficients;

[0134] (spoiler deflection) represents the effect of spoiler deflection on the corresponding coefficient;

[0135] (aileron deflection) represents the effect of aileron deflection on the corresponding coefficient;

[0136] (rudder deflection) represents the effect of pedal deflection on the corresponding coefficient;

[0137] (sideslip) represents the effect of sideslip on the corresponding coefficient;

[0138] (Landing gear represents the impact of landing gear on the corresponding coefficient;

[0139] (aerodynamic thrust effects) represents the influence of aerodynamic thrust effects on the corresponding coefficients;

[0140] (high lift device failure) represents the effect of high lift device failure on the corresponding coefficient;

[0141] (icing) represents the effect of icing on the corresponding coefficient;

[0142] (windmilling engine) represents the influence of the engine windmill characteristics on the corresponding coefficients;

[0143] (reverse thrust effects) represents the influence of reverse thrust effects on the corresponding coefficients;

[0144] (shift of the center of gravity from aerodynamic reference point) represents the effect of the change in the position of the aircraft's center of gravity on the corresponding coefficient;

[0145] (ground effect at non-zero bank angle) represents the influence of ground effect at non-zero bank angle on the corresponding coefficient;

[0146] The six-degree-of-freedom equations:

[0147] ;

[0148] ;

[0149] ;

[0150] ;

[0151] ;

[0152] ;

[0153] in, is the gross weight of the aircraft; They are the incremental velocity change rates along the xyz axes; It is thrust; is the angle of attack; is the sideslip angle; is the pitch angle; is the roll angle; are the moments of inertia around the xyz axes; are the incremental angular velocities around the xyz axes;

[0154] By points The current aircraft speed and position can be obtained by integrating The aircraft attitude angular velocity and attitude angle at the current moment can be obtained, and the calculated aircraft state is continuously updated with the time step. The integration process is a prior art and will not be described in detail here.

[0155] S6, and based on the aircraft state parameters, a difference algorithm can be used to calculate new incremental aerodynamic coefficients (for details, please refer to the literature, Aerodynamic coefficient autonomous correction method and its application in flight simulation), and can also be obtained by reference to "CN117910145B Aerodynamic coefficient determination method, determination device and storage medium"; based on the new incremental aerodynamic coefficients, the incremental aerodynamic force caused by the wake is calculated, and based on the incremental aerodynamic force, the incremental velocity and incremental angular velocity are calculated and integrated to obtain updated aircraft state parameters (according to the above steps S1-S5). As the number of coefficient iterations increases, the updated aircraft state parameters tend to be consistent with the actual flight parameters, so that the results of both the simulation and actual flight state parameters are within the ±5% error band, thereby improving the pilot's emergency response capability in this scenario, ensuring flight safety, and thus improving the training effect.

[0156] Although the various steps in the above embodiment are described in the above-mentioned order, those skilled in the art will understand that in order to achieve the effect of this embodiment, different steps do not have to be executed in such an order. They can be executed simultaneously (in parallel) or in a reverse order. These simple changes are within the scope of protection of the present invention.

[0157] A second embodiment of the present invention is a system for simulating the encounter effect of twin vortices in a flight simulator. Based on the aforementioned method for simulating the encounter effect of twin vortices in a flight simulator, the system comprises:

[0158] The wake vortex parameter generation module is configured to obtain the wake vortex parameters based on the operation-related parameters of the preceding aircraft in the flight simulator training scenario through a pre-built wake vortex model;

[0159] The wake vortex strength calculation module is configured to establish a wake vortex strength model for each stage based on the wake vortex parameters and the dimensionless buoyancy frequency according to the stage of wake dissipation of the preceding aircraft, and obtain the wake vortex strength value for the corresponding stage;

[0160] an induced velocity calculation module configured to determine the location of a vortex; calculate the distance from any point on a subsequent aircraft encountering the wake vortex to the location of the vortex; and calculate the induced velocity of a single vortex at any point based on the distance;

[0161] a relative distance evaluation module configured to calculate a current tail vortex intensity ratio based on the tail vortex intensity value and the tail vortex initial circulation, and compare the ratio with a critical value to obtain a relative distance between the preceding aircraft and the succeeding aircraft;

[0162] The state parameter calculation module is configured to select different methods to calculate the incremental speed and incremental angular speed of the entire aircraft according to the relative distance between the preceding aircraft and the succeeding aircraft; and integrate the incremental speed and incremental angular speed respectively to obtain the aircraft state parameters.

[0163] It should be noted that the above embodiment provides a dual-tail vortex encounter effect simulation system for a flight simulator, which is only illustrated by the division of the above functional modules. In actual applications, the above functions can be assigned to different functional modules as needed, that is, the modules or steps in the embodiments of the present invention can be decomposed or combined. For example, the modules in the above embodiment can be combined into one module, or further divided into multiple sub-modules to complete all or part of the functions described above. The names of the modules and steps involved in the embodiments of the present invention are only for distinguishing the modules or steps and are not regarded as improper limitations on the present invention.

[0164] Those skilled in the art should be able to appreciate that the modules and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two, and the programs corresponding to the software modules and method steps can be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disks, removable disks, CD-ROMs, or any other form of storage medium known in the art. In order to clearly illustrate the interchangeability of electronic hardware and software, the above description has generally described the components and steps of each example according to their functions. Whether these functions are performed in electronic hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0165] The terms "first", "second", etc. are used to distinguish similar objects, rather than to describe or indicate a particular order or sequence.

[0166] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed or inherent to such process, method, article, or apparatus.

[0167] Thus far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art may make equivalent changes or substitutions to the relevant technical features, and the technical solutions after such changes or substitutions will fall within the scope of protection of the present invention.

Claims

1. A method for simulating the double-tail vortex encounter effect of a flight simulator, characterized in that: The method comprises the following steps: S1, based on the operation-related parameters of the preceding aircraft in the flight simulator training scenario, obtains the wake vortex parameters through the pre-built wake vortex model; S2, according to the stage of wake dissipation of the preceding aircraft, establishing a wake vortex strength model for each stage based on the wake vortex parameters and the dimensionless buoyancy frequency, and obtaining a wake vortex strength value for the corresponding stage; S3, determining the vortex position; calculating the distance from any point on the subsequent aircraft encountering the wake vortex to the vortex position, and calculating the induced velocity of a single vortex at any point based on the distance; S4, calculating a current tail vortex intensity ratio based on the tail vortex intensity value and the tail vortex initial circulation, and comparing the ratio with a critical value to obtain a relative distance between the preceding aircraft and the succeeding aircraft; S5, selecting different methods to calculate the incremental velocity and incremental angular velocity of the entire aircraft based on the relative distance between the preceding aircraft and the succeeding aircraft; integrating the incremental velocity and incremental angular velocity to obtain aircraft state parameters, the aircraft state parameters including the aircraft's velocity, position, attitude angular velocity, and attitude angle; According to the relative distance between the preceding aircraft and the succeeding aircraft, different methods are selected to calculate the incremental velocity and incremental angular velocity of the entire aircraft. The method is: If the relative distance between the preceding aircraft and the succeeding aircraft is relatively close, the succeeding aircraft is split into predetermined load-bearing components and the induced velocity of each load-bearing component is calculated. An incremental aerodynamic force is calculated based on the induced velocity. The incremental velocity and incremental angular velocity of the corresponding load-bearing component are obtained by integration, and the incremental velocity and incremental angular velocity of each load-bearing component are added together to obtain the incremental velocity and incremental angular velocity of the entire aircraft. If the relative distance between the preceding aircraft and the succeeding aircraft is relatively far, the incremental aerodynamic force is calculated based on the induced velocity, and the incremental velocity and incremental angular velocity of the entire aircraft are obtained by applying the incremental aerodynamic force and control parameters to the six-degree-of-freedom equation; The incremental speeds are u, v, w; the incremental angular speeds are p, q, r; The incremental aerodynamic force includes lift, drag, side force, rolling moment, pitching moment, and heading moment. The calculation method of each parameter in the incremental aerodynamic force is: Lift: ; resistance: ; Lateral force: ; Rolling moment: ; Pitching moment: ; Heading moment: ; in, is the induced velocity; is the current air density; is the projected area of ​​the entire aircraft; is the wing span; is the average aerodynamic chord length of the wing; is the lift coefficient; is the drag coefficient; is the lateral force coefficient; is the rolling moment coefficient; is the pitching moment coefficient; is the yaw moment coefficient.

2. A method for simulating the double-tail vortex encounter effect for a flight simulator according to claim 1, characterized in that: The operation-related parameters include the mass, wingspan, true airspeed, normal overload and air density of the preceding aircraft; the trailing vortex parameters include the trailing vortex initial circulation, vortex core radius, characteristic time and trailing vortex characteristic speed; The initial circulation of the tail vortex: ； ； in, is the initial vortex circulation; is the normal overload of the aircraft; is the mass of the preceding aircraft; is the acceleration due to gravity; is the air density; is the true airspeed of the preceding aircraft; is the initial vortex distance; Vortex core radius: ； is the vortex core radius; is the aircraft wingspan; is the initial vortex core radius; Trailing vortex characteristic velocity: ； Feature time: ； in, is the characteristic time; Characteristic velocity of the trailing vortex.

3. The method for simulating the double-tail vortex encounter effect for a flight simulator according to claim 1, wherein: The stages of wake dissipation of the preceding aircraft include a diffusion stage and a rapid decay stage; The tail vortex strength model of the diffusion stage is: ； The tail vortex strength model in the rapid decay stage is: ； in, is the trailing vortex intensity value after the diffusion stage decays; is the dimensionless buoyancy frequency; is the duration of the wake vortex effect; is the duration of the diffusion phase.

4. The method for simulating the double-tail vortex encounter effect for a flight simulator according to claim 1, wherein: The method to determine the eddy current position is: Select a cross section perpendicular to the wake field, take the midpoint of the line connecting the left and right vortex cores as the origin, establish a coordinate system with the x-axis along the line and the y-axis perpendicular to the line; The left and right vortices are located at (0, B / 2) and (0, −B / 2) in the coordinate system respectively.

5. The method for simulating the double-tail vortex encounter effect for a flight simulator according to claim 1, wherein: The induced velocity of the single vortex at any point is obtained as follows: Based on the positions of the left and right vortices, calculate the distance from any point on the aircraft encountering the wake vortex to the vortex position: ； Calculate the induced velocity of a single vortex at any point based on the distance: ； in, is the distance from any point of the subsequent aircraft to the origin; is the strength of the wake vortex encountered by the subsequent aircraft; x and y are the coordinates of any point on the aircraft.

6. The method for simulating the double-tail vortex encounter effect for a flight simulator according to claim 1, wherein: The relative distance between the preceding aircraft and the succeeding aircraft is obtained by: Calculate the ratio of the current trailing vortex strength: ; The current tail vortex strength ratio is compared with the critical value to obtain the relative distance between the preceding aircraft and the succeeding aircraft: When D is less than or equal to the critical value, it is determined that the relative distance between the preceding aircraft and the succeeding aircraft is far; otherwise, it is determined that the relative distance between the preceding aircraft and the succeeding aircraft is close.

7. The method for simulating the double-tail vortex encounter effect for a flight simulator according to claim 1, wherein: The six-degree-of-freedom equations: ； ； ； ； ； ； in, is the gross weight of the aircraft; They are the incremental velocity change rates along the xyz axes; It is thrust; is the angle of attack; is the sideslip angle; is the pitch angle; is the roll angle; are the moments of inertia around the xyz axes; They are the incremental angular velocity change rates around the xyz axes, is the incremental angular velocity, that is, the incremental angular velocity around the xyz axes.

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