Flying wing layout aircraft single-shot failure flight quality evaluation method and system

Abstract

The invention provides a flying wing layout aircraft single-shot failure flight quality evaluation method which comprises the following steps: a control surface balance parameter calculation step: ignoring lateral displacement caused by sideslip angle change, and calculating a change curve of asymmetric rolling and yawing moment caused by balanced single-shot failure, required aileron skewness delta a and rudder skewness delta r along with speed; a control surface balance capability evaluation step: judging whether the aircraft can be balanced after single-engine failure at each speed by judging whether the aileron skewness delta a and the rudder skewness delta r exceed limit values or not, and evaluating the flight quality of the aircraft after single-engine failure; a time domain response simulation step: performing time domain simulation after a single aircraft engine fails; and an attitude keeping capability evaluation step: based on a time domain simulation result after the single aircraft engine fails, judging the attitude change degree of the aircraft, and evaluating the flight quality of the single aircraft engine failure. On the other hand, the invention provides a flying wing layout aircraft single-shot failure flight quality evaluation system.

Description

Technical Field

[0001] The present application belongs to the technical field of single-engine failure flight quality assessment for flying wing aircraft, and specifically relates to a single-engine failure flight quality assessment method and system for a flying wing aircraft. Background Art

[0001] The failure of a single engine of an aircraft will seriously affect the flight safety of the aircraft and easily cause flight accidents.

[0002] When designing conventional aircraft, the aircraft's lateral static balance equation is mainly used to calculate the ability of the control surface to balance the asymmetric torque caused by a single engine failure, and to evaluate the aircraft's single engine failure flight quality. The aircraft's roll angle is an input parameter of the aircraft's lateral static balance equation. Within a range of 5°, it will not bring about a significant change in the calculation results.

[0003] Since the flying wing layout aircraft has eliminated the tail, its lateral force coefficient is much lower than that of the conventional layout aircraft. Even in the case of a small roll angle, there is a big difference between the component of the lift on the lateral projection of the aircraft and the lateral force caused by the aircraft's sideslip. A slight change in the aircraft's roll angle will cause a large change in the calculation result of the aircraft's lateral static balance equation. In severe cases, the required control surfaces may even be reversed, and this can no longer be used to accurately evaluate the flight quality of the aircraft in the event of a single-engine failure.

[0004] This application is proposed in view of the above-mentioned technical defects. Summary of the invention

[0002] The purpose of the present application is to provide a method and system for evaluating the flight quality of a flying wing aircraft with a single engine failure, so as to overcome or alleviate at least one of the known technical defects.

[0003] The technical solution of this application is:

[0004] On the one hand, a method for evaluating the flight quality of a flying wing aircraft with a single engine failure is provided, comprising:

[0005] The calculation steps of control surface balance parameters are as follows: Ignore the lateral displacement caused by the change of sideslip angle and calculate different roll angles Under the condition of balanced single engine failure, asymmetric rolling and yaw moments are caused, and the required aileron deflection δ a 、Rudder deflection δ r Curve of change with speed;

[0006] Control surface balance ability assessment steps: through aileron deflection δ a 、Rudder deflection δ r Whether it exceeds the limit value, judge whether the aircraft can be balanced after a single engine failure at each speed, and evaluate the flight quality of the aircraft after a single engine failure;

[0007] Time domain response simulation steps: Perform time domain simulation after a single engine failure of the aircraft;

[0008] Attitude holding capability assessment steps: Based on the time domain simulation results after a single engine failure, determine the degree of aircraft attitude change and assess the flight quality of the aircraft when a single engine fails.

[0009] According to at least one embodiment of the present application, in the above-mentioned flying wing aircraft single-engine failure flight quality assessment method, in the control surface balance parameter calculation step, the aileron deflection δ is calculated. a 、Rudder deflection δ r , specifically:

[0010]

[0011]

[0012]

[0013] in,

[0014] is the roll angle, δ a is the aileron deflection; δ r is the rudder deflection;

[0015] is the rudder side force, roll, and yaw control moment coefficient;

[0016] C L is the lift coefficient, is the roll and yaw control moment coefficient of the aileron;

[0017] C lbu , C nbu It is the asymmetric rolling and yaw moment generated when a single engine fails.

[0018] According to at least one embodiment of the present application, in the above-mentioned flying wing aircraft single-engine failure flight quality assessment method, in the control surface balance ability assessment step, if the aileron deflection δ a 、Rudder deflection δ r If all of them do not exceed the limit value, it is judged that the failure of a single engine at each speed can be within the feasible range by adjusting the aileron deflection δ a 、Rudder deflection δ r Balance the aircraft and evaluate the single-engine failure flight quality of the aircraft as excellent. Otherwise, it is judged that the single-engine failure at each speed is not within the feasible range. By adjusting the aileron deflection δ a 、Rudder deflection δ r Balance the aircraft and assess the aircraft's single-engine failure flying qualities as poor.

[0019] According to at least one embodiment of the present application, in the above-mentioned method for evaluating the flight qualities of a flying wing aircraft with a single engine failure, in the time domain response simulation step, a time domain simulation is performed after a single engine failure of the aircraft in combination with the six-degree-of-freedom motion equation.

[0020] According to at least one embodiment of the present application, in the above-mentioned flying wing aircraft single-engine failure flight quality assessment method, in the attitude holding capability assessment step, if the aircraft attitude change degree is small, then it is judged that the dynamic response of the aircraft after the single-engine failure is small, and the aircraft single-engine failure flight quality is evaluated to be excellent; otherwise, it is judged that the dynamic response of the aircraft after the single-engine failure is large, and the aircraft single-engine failure flight quality is evaluated to be poor.

[0021] According to at least one embodiment of the present application, in the above-mentioned flying wing aircraft single-engine failure flight quality assessment method, in the attitude holding ability assessment step, the degree of aircraft attitude change is evaluated by the sideslip angle β, roll angle β and the like after the single-engine failure. to determine the degree of change.

[0022] On the other hand, a single-engine failure flight quality assessment system for a flying wing aircraft is provided, comprising:

[0023] Control surface balance parameter calculation module: Ignore the lateral displacement caused by the change of sideslip angle and calculate different roll angles Under the condition of balanced single engine failure, asymmetric rolling and yaw moments are caused, and the required aileron deflection δ a 、Rudder deflection δ r Curve of change with speed;

[0024] Control surface balance ability evaluation module: through aileron deflection δ a 、Rudder deflection δ r Whether it exceeds the limit value, judge whether the aircraft can be balanced after a single engine failure at each speed, and evaluate the flight quality of the aircraft after a single engine failure;

[0025] Time domain response simulation module: performs time domain simulation after a single engine failure of an aircraft;

[0026] Attitude holding capability assessment module: Based on the time domain simulation results after a single engine failure, the module determines the degree of change in the aircraft's attitude and assesses the flight quality of the aircraft when a single engine fails.

[0027] According to at least one embodiment of the present application, in the above-mentioned flying wing aircraft single-engine failure flight quality assessment system, in the control surface balance parameter calculation module, the aileron deflection δ is calculated. a 、Rudder deflection δ r , specifically:

[0028]

[0029]

[0030]

[0031] in,

[0032] is the roll angle, δ a is the aileron deflection; δ r is the rudder deflection;

[0033] is the rudder side force, roll, and yaw control moment coefficient;

[0034] C L is the lift coefficient, is the roll and yaw control moment coefficient of the aileron;

[0035] C lbu , C nbu It is the asymmetric rolling and yaw moment generated when a single engine fails.

[0036] According to at least one embodiment of the present application, in the above-mentioned flying wing aircraft single-engine failure flight quality assessment system, in the control surface balance capability assessment module, if the aileron deflection δ a 、Rudder deflection δ r If all of them do not exceed the limit value, it is judged that the failure of a single engine at each speed can be within the feasible range by adjusting the aileron deflection δ a 、Rudder deflection δ r Balance the aircraft and evaluate the single-engine failure flight quality of the aircraft as excellent. Otherwise, it is judged that the single-engine failure at each speed is not within the feasible range. By adjusting the aileron deflection δ a 、Rudder deflection δ r Balance the aircraft and assess the aircraft's single-engine failure flying qualities as poor.

[0037] According to at least one embodiment of the present application, in the above-mentioned flying wing aircraft single-engine failure flight quality assessment system, the time domain response simulation module combines the six-degree-of-freedom motion equations to perform time domain simulation after a single-engine failure of the aircraft.

[0038] According to at least one embodiment of the present application, in the above-mentioned flying wing aircraft single-engine failure flight quality assessment system, in the attitude holding capability assessment module, if the aircraft attitude change degree is small, then it is judged that the dynamic response of the aircraft after the single-engine failure is small, and the aircraft single-engine failure flight quality is evaluated to be excellent; otherwise, it is judged that the dynamic response of the aircraft after the single-engine failure is large, and the aircraft single-engine failure flight quality is evaluated to be poor.

[0039] According to at least one embodiment of the present application, in the above-mentioned flying wing aircraft single-engine failure flight quality assessment system, in the attitude holding capability assessment module, for the degree of aircraft attitude change, the sideslip angle β, the roll angle β and the roll angle β after the single-engine failure are calculated. to determine the degree of change.

[0040] This application has at least the following beneficial technical effects:

[0041] A method and system for evaluating the flight quality of a flying wing aircraft with a single engine failure are provided. The lateral displacement caused by the change of the sideslip angle is ignored, the lateral static balance of the single engine failure is calculated, and only the ability of the roll and yaw control effectiveness to balance the asymmetric roll and yaw moments caused by the single engine failure is evaluated. At the same time, combined with time domain simulation, the attitude change of the aircraft after the single engine failure is observed, and the flight quality of the aircraft with a single engine failure is comprehensively evaluated, which is efficient and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The embodiment of the present application provides a conventional layout aircraft with a single engine failure, and different roll angles The curve of the sideslip angle β required to balance the asymmetric torque caused by a single engine failure versus speed;

[0043] Figure 2 The embodiment of the present application provides a conventional layout aircraft with a single engine failure, and different roll angles The rudder deflection δ required to balance the asymmetric moment caused by a single engine failure is r Curve of change with speed;

[0044] Figure 3 The embodiment of the present application provides a flying wing layout aircraft with a single engine failure, and different roll angles The curve of the sideslip angle β required to balance the asymmetric torque caused by a single engine failure versus speed;

[0045] Figure 4 The embodiment of the present application provides a flying wing layout aircraft with a single engine failure, and different roll angles The rudder deflection δ required to balance the asymmetric moment caused by a single engine failure is r Curve of change with speed;

[0046] Figure 5 is a schematic diagram of a method for evaluating the flying qualities of a flying wing aircraft with a single engine failure provided in an embodiment of the present application;

[0047] Figure 6 The embodiment of the present application provides a flying wing layout aircraft with a single engine failure, and different roll angles Under this condition, the asymmetric yaw moment curve with speed is generated;

[0048] Figure 7The embodiment of the present application provides a flying wing layout aircraft with a single engine failure, and different roll angles The rudder deflection δ required to balance the asymmetric yaw moment is r Schematic diagram of the curve of change with speed;

[0049] Figure 8 It is a schematic diagram of a curve showing a change in the sideslip angle β over time at different speeds after a single engine failure of a flying wing layout aircraft provided in an embodiment of the present application;

[0050] Fig. 9 The rolling angle at different speeds after a single engine failure of a flying wing aircraft provided in the embodiment of the present application is Schematic diagram of the curve of change over time;

[0051] Fig.10 It is a schematic diagram of a single-engine failure flight quality assessment system for a flying wing aircraft provided in an embodiment of the present application.

[0052] In order to better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. In addition, the drawings are only used for illustrative purposes and should not be construed as limitations on the present application. DETAILED DESCRIPTION

[0053] In order to make the technical solution and advantages of the present application clearer, the technical solution of the present application will be described in further detail in detail and in detail with reference to the accompanying drawings. It can be understood that the specific embodiments described here are only partial embodiments of the present application, which are only used to explain the present application, not to limit the present application. It should be noted that, for the convenience of description, only the parts related to the present application are shown in the accompanying drawings, and other related parts can refer to the general design.

[0054] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of this application shall have the usual meanings understood by those of ordinary skill in the art to which this application belongs. The words used in the description of this application to indicate orientation are only used to indicate relative directions or positional relationships. When the absolute position of the described object changes, its relative positional relationship may also change accordingly. The word "include" used in the description of this application indicates that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but does not exclude other elements or objects.

[0055] In addition, it should be noted that, unless otherwise clearly specified and limited, the words "installation", "connection" and similar terms used in the description of this application should be understood in a broad sense. For example, the connection can be a fixed connection or a detachable connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. Technical personnel in the field can understand its specific meaning in this application according to the specific circumstances.

[0056] The static balance equation of the aircraft in lateral direction after a single engine failure is:

[0057]

[0058]

[0059]

[0060] in,

[0061] C Yβ , C lβ , C nβ is the derivative of the lateral moment, rolling moment and yaw moment with respect to the sideslip angle;

[0062] is the roll angle, β is the sideslip angle, δ a is the aileron deflection; δ r is the rudder deflection;

[0063] is the rudder side force, roll, and yaw control moment coefficient;

[0064] C L is the lift coefficient, is the roll and yaw control moment coefficient of the aileron;

[0065] C lbu , C nbu It is the asymmetric rolling and yaw moment generated when a single engine fails.

[0066] For conventional aircraft, different roll angles are usually Substitute the aircraft's lateral static balance equation and solve for different roll angles Under the condition of single engine failure, the required sideslip angle β and aileron deflection δ are a 、Rudder deflection δ r The curve of the change with speed. Through the sideslip angle β, rudder deflection δ r Whether it exceeds the limit value, determine whether the aircraft can be balanced after a single engine failure at each speed, and evaluate the flight quality of the aircraft after a single engine failure.

[0067] After a single engine failure of a conventional aircraft, different roll angles Under the condition of single engine failure, the required sideslip angle β and rudder deflection δ are r The curve of speed change, such as Figure 1 , Figure 2 As shown, different roll angles can be seen Enter the sideslip angle β and rudder δ required for static balance after one engine failure r The skewness results have little impact.

[0068] For flying wing layout aircraft, due to the elimination of the tail, its side force coefficient and lateral static stability derivative are reduced by 1 or even 2 orders of magnitude compared with conventional layout aircraft. Within the range of input variation, the lift component on the lateral projection of the aircraft is very different from the lateral force caused by the aircraft's sideslip. If the deviation is too small, it will cause a large change in the deflection of the control surface required for balance, or even a reverse sign, making it impossible to accurately evaluate the conformity of the calculation results.

[0069] After a single engine failure of a flying wing aircraft, different roll angles Under the condition of single engine failure, the required sideslip angle β and rudder deflection δ are r The curve of speed change, such as Figure 3 , Figure 4 As shown, different roll angles can be seen Enter the sideslip angle β and rudder δ required for static balance after one engine failure r The skewness results have a significant impact.

[0070] The lateral force level of a flying wing aircraft is small, and the method for evaluating the flight quality of a conventional aircraft with a single engine failure cannot be applied to the design evaluation of a flying wing aircraft. In this regard, the present application provides a method for evaluating the flight quality of a flying wing aircraft with a single engine failure, such as Figure 5 As shown, a new method is provided for evaluating the flight quality of a flying wing aircraft with a single engine failure.

[0071] Since the lateral force system of a flying wing aircraft is of a very small magnitude and the lateral displacement caused by sideslip is also very small, the lateral displacement caused by the change in sideslip angle can be ignored when calculating the lateral static balance of an aircraft with a single-engine failure. Only the ability of the roll and yaw control effectiveness to balance the asymmetric roll and yaw moments caused by the single-engine failure can be evaluated. At the same time, time domain simulation can be combined to observe the changes in the aircraft's attitude after a single-engine failure, and the results of the aircraft's single-engine failure flight quality can be comprehensively obtained.

[0072] The calculation steps of control surface balance parameters are as follows: Ignore the lateral displacement caused by the change of sideslip angle and calculate different roll angles Under the condition of balanced single engine failure, asymmetric rolling and yaw moments are caused, and the required aileron deflection δ a 、Rudder deflection δr The curve of speed change.

[0073]

[0074]

[0075]

[0076] in,

[0077] is the roll angle, δ a is the aileron deflection; δ r is the rudder deflection;

[0078] is the rudder side force, roll, and yaw control moment coefficient;

[0079] C L is the lift coefficient, is the roll and yaw control moment coefficient of the aileron;

[0080] C lbu , C nbu It is the asymmetric rolling and yaw moment generated when a single engine fails.

[0081] Control surface balance ability assessment steps: through aileron deflection δ a 、Rudder deflection δ r Whether it exceeds the limit value, determine whether the aircraft can be balanced after a single engine failure at each speed, and evaluate the flight quality of the aircraft after a single engine failure.

[0082] If the aileron skewness δ a 、Rudder deflection δ r If all of them do not exceed the limit value, it is judged that the failure of a single engine at each speed can be within the feasible range by adjusting the aileron deflection δ a 、Rudder deflection δ r Balance the aircraft and evaluate the single-engine failure flight quality of the aircraft as excellent. Otherwise, it is judged that the single-engine failure at each speed is not within the feasible range. By adjusting the aileron deflection δ a 、Rudder deflection δ r Balance the aircraft and assess the aircraft's single-engine failure flying qualities as poor.

[0083] Time domain response simulation steps: Perform time domain simulation after a single engine failure of the aircraft.

[0084] Specifically, the six-degree-of-freedom motion equation is combined to perform time domain simulation after a single engine failure of the aircraft.

[0085] Attitude holding capability assessment steps: Based on the time domain simulation results after a single engine failure, determine the degree of aircraft attitude change and assess the flight quality of the aircraft when a single engine fails.

[0086] If the degree of change in the aircraft's attitude is small, it is judged that the dynamic response of the aircraft after a single-engine failure is small, and the aircraft's single-engine failure flight quality is evaluated as excellent. Otherwise, it is judged that the dynamic response of the aircraft after a single-engine failure is large, and the aircraft's single-engine failure flight quality is evaluated as poor.

[0087] For the degree of change of aircraft attitude, the sideslip angle β and roll angle after single engine failure are calculated. to determine the degree of change.

[0088] In a specific example, after a single engine failure of a flying wing aircraft, different roll angles Under this condition, the asymmetric yaw moment changes with speed, as shown in Figure 6 As shown, the rudder deflection δ required for balance r The curve of speed change, such as Figure 7 As shown, the rudder deflection δ r The aileron deflection δ required to balance the asymmetric rolling moment does not exceed the limit value. a , and there are similar results. It is believed that after a single engine failure at each speed, it is possible to adjust the aileron deflection δ within the feasible range. a 、Rudder deflection δ r Balance the aircraft and assess its single-engine failure flying qualities as excellent.

[0089] In addition, after a single engine failure of a flying wing aircraft, the sideslip angle β and roll angle at different speeds The curve of change over time, such as Figure 8 , Fig. 9 As shown in the figure, it can be seen that the dynamic response of the aircraft is small after a single engine fails. The aircraft will not experience a large attitude change instantly after a single engine fails. For the pilot, there is enough time to control the aircraft and maintain the aircraft's attitude. The adverse roll angle can be eliminated by manipulating the aileron and rudder. and sideslip angle β until the aircraft's attitude remains balanced. During this process, the aircraft will not respond violently. The aircraft's flight quality with single-engine failure can be evaluated as excellent. It can be considered that the flying quality of the flying wing layout aircraft with single-engine failure meets the design requirements.

[0090] The method for evaluating the flight quality of a flying wing aircraft with a single engine failure disclosed in the above-mentioned embodiment ignores the lateral displacement caused by the change in the sideslip angle, calculates the lateral static balance of the single engine failure, and only evaluates the ability of the roll and yaw control effectiveness to balance the asymmetric roll and yaw moments caused by the single engine failure. At the same time, combined with time domain simulation, the attitude change of the aircraft after the single engine failure is observed, and the flight quality of the aircraft with a single engine failure is comprehensively evaluated, which is efficient and convenient.

[0091] On the other hand, the present application provides a flying wing aircraft single engine failure flight quality assessment system, such as Fig.10 As shown, including:

[0092] Control surface balance parameter calculation module: Ignore the lateral displacement caused by the change of sideslip angle and calculate different roll angles Under the condition of balanced single engine failure, asymmetric rolling and yaw moments are caused, and the required aileron deflection δ a 、Rudder deflection δ r Curve of change with speed;

[0093] Control surface balance ability evaluation module: through aileron deflection δ a 、Rudder deflection δ r Whether it exceeds the limit value, judge whether the aircraft can be balanced after a single engine failure at each speed, and evaluate the flight quality of the aircraft after a single engine failure;

[0094] Time domain response simulation module: performs time domain simulation after a single engine failure of an aircraft;

[0095] Attitude holding capability assessment module: Based on the time domain simulation results after a single engine failure, the module determines the degree of change in the aircraft's attitude and assesses the flight quality of the aircraft when a single engine fails.

[0096] Optionally, in the above-mentioned flying wing aircraft single-engine failure flight quality assessment system, in the control surface balance parameter calculation module, the aileron deflection δ is calculated a 、Rudder deflection δ r , specifically:

[0097]

[0098]

[0099]

[0100] in,

[0101] is the roll angle, δ a is the aileron deflection; δ r is the rudder deflection;

[0102] is the rudder side force, roll, and yaw control moment coefficient;

[0103] C L is the lift coefficient, is the roll and yaw control moment coefficient of the aileron;

[0104] C lbu , C nbu It is the asymmetric rolling and yaw moment generated when a single engine fails.

[0105] Optionally, in the above-mentioned flying wing aircraft single-engine failure flight quality assessment system, in the control surface balance capability assessment module, if the aileron deflection δ a 、Rudder deflection δ r If all of them do not exceed the limit value, it is judged that the failure of a single engine at each speed can be within the feasible range by adjusting the aileron deflection δ a 、Rudder deflection δ r Balance the aircraft and evaluate the single-engine failure flight quality of the aircraft as excellent. Otherwise, it is judged that the single-engine failure at each speed is not within the feasible range. By adjusting the aileron deflection δ a 、Rudder deflection δ r Balance the aircraft and assess the aircraft's single-engine failure flying qualities as poor.

[0106] Optionally, in the above-mentioned flying wing aircraft single-engine failure flight quality assessment system, in the time domain response simulation module, the six-degree-of-freedom motion equation is combined to perform a time domain simulation after a single-engine failure of the aircraft.

[0107] Optionally, in the above-mentioned flying wing aircraft single-engine failure flight quality assessment system, in the attitude holding capability assessment module, if the aircraft attitude change degree is small, then the dynamic response of the aircraft after the single-engine failure is judged to be small, and the aircraft single-engine failure flight quality is assessed to be excellent; otherwise, the dynamic response of the aircraft after the single-engine failure is judged to be large, and the aircraft single-engine failure flight quality is assessed to be poor.

[0108] Optionally, in the above-mentioned flying wing aircraft single-engine failure flight quality assessment system, in the attitude holding capability assessment module, the degree of aircraft attitude change is evaluated by the sideslip angle β, the roll angle after the single-engine failure to determine the degree of change.

[0109] Regarding the flying quality assessment system for a flying wing aircraft with a single engine failure disclosed in the above-mentioned embodiment, since it corresponds to the flying quality assessment method for a flying wing aircraft with a single engine failure disclosed in the above-mentioned embodiment, the description is relatively simple. For specific related matters, please refer to the relevant description of the flying quality assessment method for a flying wing aircraft with a single engine failure. Its technical effects can also refer to the technical effects of the relevant parts of the flying quality assessment method for a flying wing aircraft with a single engine failure, and will not be repeated here.

[0110] In addition, technicians in the field should also be able to realize that the various modules and units of the flying wing layout aircraft single-engine failure flight quality assessment system disclosed in the embodiments of the present application can be implemented by electronic hardware, computer software or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, this application generally describes them according to their functions. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Technicians in the field can choose to adopt different methods to implement the described functions for each specific application and its actual constraints, but such implementation should not be considered to exceed the scope of this application.

[0111] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of the present application is obviously not limited to these specific embodiments. Without departing from the principles of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the scope of protection of the present application.

Claims

1. A method for evaluating the flight quality of a flying wing aircraft with a single engine failure, characterized in that: include: The calculation steps of control surface balance parameters are as follows: Ignore the lateral displacement caused by the change of sideslip angle and calculate different roll angles Under the condition of balanced single engine failure, asymmetric rolling and yaw moments are caused, and the required aileron deflection δ a 、Rudder deflection δ r Curve of change with speed; Control surface balance ability assessment steps: through aileron deflection δ a 、Rudder deflection δ r Whether it exceeds the limit value, judge whether the aircraft can be balanced after a single engine failure at each speed, and evaluate the flight quality of the aircraft after a single engine failure; Time domain response simulation steps: Perform time domain simulation after a single engine failure of the aircraft; Attitude holding capability assessment steps: Based on the time domain simulation results after a single engine failure, determine the degree of aircraft attitude change and assess the flight quality of the aircraft when a single engine fails.

2. The flying quality assessment method for a flying wing aircraft with a single engine failure according to claim 1, characterized in that: In the control surface balance parameter calculation step, calculate the aileron deflection δ a 、Rudder deflection δ r , specifically: in, is the roll angle, δ a is the aileron deflection; δ r is the rudder deflection; is the rudder side force, roll, and yaw control moment coefficient; C L is the lift coefficient, is the roll and yaw control moment coefficient of the aileron; C lbu , C nbu It is the asymmetric rolling and yaw moment generated when a single engine fails.

3. The flying quality assessment method for a flying wing aircraft with a single engine failure according to claim 2, characterized in that: In the control surface balance ability evaluation step, if the aileron deflection δ a 、Rudder deflection δ r If all of them do not exceed the limit value, it is judged that the failure of a single engine at each speed can be within the feasible range by adjusting the aileron deflection δ a 、Rudder deflection δ r Balance the aircraft and evaluate the single-engine failure flight quality of the aircraft as excellent. Otherwise, it is judged that the single-engine failure at each speed is not within the feasible range. By adjusting the aileron deflection δ a 、Rudder deflection δ r Balance the aircraft and assess the aircraft's single-engine failure flying qualities as poor.

4. The flying quality assessment method for a flying wing aircraft with a single engine failure according to claim 3 is characterized in that: In the time domain response simulation step, the six-degree-of-freedom motion equation is combined to perform a time domain simulation after a single engine failure of the aircraft.

5. The method for evaluating the flying qualities of a flying wing aircraft with a single engine failure according to claim 4, characterized in that: In the attitude holding capability assessment step, if the aircraft attitude change degree is small, it is judged that the dynamic response of the aircraft after a single engine failure is small, and the aircraft single-engine failure flight quality is assessed to be excellent; otherwise, it is judged that the dynamic response of the aircraft after a single engine failure is large, and the aircraft single-engine failure flight quality is assessed to be poor.

6. The method for evaluating the flying qualities of a flying wing aircraft with a single engine failure according to claim 5, characterized in that: In the attitude holding capability assessment step, the degree of aircraft attitude change is evaluated by the sideslip angle β and roll angle after single engine failure. to determine the degree of change.

7. A flying wing aircraft single engine failure flight quality assessment system, characterized in that: include: Control surface balance parameter calculation module: Ignore the lateral displacement caused by the change of sideslip angle and calculate different roll angles Under the condition of balanced single engine failure, asymmetric rolling and yaw moments are caused, and the required aileron deflection δ a 、Rudder deflection δ r Curve of change with speed; Control surface balance ability evaluation module: through aileron deflection δ a 、Rudder deflection δ r Whether it exceeds the limit value, judge whether the aircraft can be balanced after a single engine failure at each speed, and evaluate the flight quality of the aircraft after a single engine failure; Time domain response simulation module: performs time domain simulation after a single engine failure of an aircraft; Attitude holding capability assessment module: Based on the time domain simulation results after a single engine failure, the module determines the degree of change in the aircraft's attitude and assesses the flight quality of the aircraft when a single engine fails.

8. The flying quality assessment system for a flying wing aircraft with a single engine failure according to claim 7, characterized in that: In the control surface balance parameter calculation module, calculate the aileron deflection δ a 、Rudder deflection δ r , specifically: in, is the roll angle, δ a is the aileron deflection; δ r is the rudder deflection; is the rudder side force, roll, and yaw control moment coefficient; C L is the lift coefficient, is the roll and yaw control moment coefficient of the aileron; C lbu , C nbu It is the asymmetric rolling and yaw moment generated when a single engine fails.

9. The flying quality assessment system for a flying wing aircraft with a single engine failure according to claim 8, characterized in that: In the control surface balance capability evaluation module, if the aileron deflection δ a 、Rudder deflection δ r If all of them do not exceed the limit value, it is judged that the failure of a single engine at each speed can be within the feasible range by adjusting the aileron deflection δ a 、Rudder deflection δ r Balance the aircraft and evaluate the single-engine failure flight quality of the aircraft as excellent. Otherwise, it is judged that the single-engine failure at each speed is not within the feasible range. By adjusting the aileron deflection δ a 、Rudder deflection δ r Balance the aircraft and assess the aircraft's single-engine failure flying qualities as poor.

10. The flying quality assessment system for a flying wing aircraft with a single engine failure according to claim 9, characterized in that: In the time domain response simulation module, the six-degree-of-freedom motion equation is combined to perform time domain simulation after a single engine failure of the aircraft.

11. The flying quality assessment system for a flying wing aircraft with a single engine failure according to claim 10, characterized in that: In the attitude holding capability assessment module, if the aircraft attitude change degree is small, it is judged that the dynamic response of the aircraft after a single engine failure is small, and the flight quality of the aircraft with a single engine failure is evaluated as excellent. Otherwise, it is judged that the dynamic response of the aircraft after a single engine failure is large, and the flight quality of the aircraft with a single engine failure is evaluated as poor.

12. The flying quality assessment system for a flying wing aircraft with a single engine failure according to claim 11, characterized in that: In the attitude holding capability assessment module, the degree of aircraft attitude change is evaluated by the sideslip angle β and roll angle after a single engine failure. to determine the degree of change.

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