A method and system for calculating the balance position of a soft aircraft refueling system cone

Abstract

The application belongs to the technical field of structural dynamics, and particularly relates to a method and system for calculating the balance position of a soft refueling system cone sleeve of an airplane. n The method comprises the following steps: determining the direction of the aerodynamic force of the cone sleeve and the direction of the aerodynamic pressure difference force of the refueling hose; calculating the aerodynamic force of the cone sleeve, the aerodynamic pressure difference force coefficient c and the aerodynamic pressure difference force of the refueling hose according to basic parameters; obtaining the force state data of the hose-cone sleeve combination in the balanced state, combining the aerodynamic force of the cone sleeve, the aerodynamic pressure difference force coefficient of the refueling hose and the aerodynamic pressure difference force of the refueling hose to establish a moment balance equation, and combining the moment balance equation with a hose length distance equation to obtain a bivariate quadratic equation set, so as to obtain the vertical distance z and the heading distance x of the balance position of the cone sleeve relative to the root of the hose. The reel winding moment of the soft refueling system of the airplane can be quickly calculated according to a small amount of data, the unsteady fluid-structure coupling analysis or the programming to establish a mathematical model for solving is avoided, and the calculation cost and period of the balance position of the cone sleeve are greatly reduced.

Description

Technical Field

[0001] The present application belongs to the field of structural dynamics technology, and in particular relates to a method and system for calculating the equilibrium position of a cone sleeve of an aircraft soft refueling system. Background Art

[0002] Aerial refueling methods are mainly divided into hard refueling and soft refueling methods. my country currently uses soft refueling, that is, a hose-drogue refueling system. When the hose is fully released and in a dragging balance state, the balance position of the drogue will determine the flow field environment of the receiving aircraft during refueling. The tanker's wake and engine jet will affect the aerodynamic compatibility of the tanker and the receiving aircraft. If the receiving aircraft is inappropriately positioned, it may affect the receiving aircraft's control stability, and in severe cases, it may cause the receiving aircraft to lose control or even crash.

[0003] Calculating the equilibrium position of the drogue-drogue assembly in an aircraft refueling system during drag equilibrium is often done through unsteady fluid-structure interaction analysis or by programming mathematical models. These methods are computationally expensive and time-consuming, making them difficult to meet the rapid iteration requirements of early aircraft design stages. Furthermore, there is a lack of a simple, universal calculation method for determining the equilibrium position of the drogue. Summary of the Invention

[0004] The purpose of this application is to provide a method and system for calculating the equilibrium position of a drogue sleeve of an aircraft soft refueling system, so as to solve the problems of high cost and long cycle in the existing drogue sleeve equilibrium position calculation.

[0005] The technical solution of this application is: a method for calculating the equilibrium position of the drogue sleeve of an aircraft soft refueling system includes:

[0006] Determine the basic parameters required for calculation;

[0007] Determine the direction of the drogue aerodynamic force and calculate the drogue aerodynamic force based on the basic parameters, including the drogue aerodynamic drag coefficient, the drogue equivalent aerodynamic area, the far-field incoming flow true air speed, and the air density corresponding to the flight altitude;

[0008] According to the basic parameters of the hose diameter, the far-field incoming flow true air speed, the aerodynamic viscosity coefficient corresponding to the flight altitude and the air density, the local Reynolds number Re of the aerodynamic pressure difference force is calculated. p =ρ·v·D / u, and then calculate the aerodynamic pressure differential force coefficient C according to the local Reynolds number of the aerodynamic pressure differential force n ;

[0009] Determine the direction of the aerodynamic pressure differential force of the refueling hose. Based on the basic parameters including hose length, hose diameter, far-field incoming flow true airspeed, and air density corresponding to the flight altitude, assume that the vertical distance of the drogue's equilibrium position relative to the hose root is z, and the heading distance is x, to obtain the aerodynamic pressure differential force of the refueling hose. Obtain the force state data of the hose-drogue combination in the equilibrium state, and establish a torque balance equation by combining the drogue aerodynamic force, the aerodynamic pressure differential force coefficient of the refueling hose, and the aerodynamic pressure differential moment of the refueling hose. Combine the torque balance equation with the hose length and distance equation to obtain a set of quadratic equations. By solving the set of quadratic equations, it is determined that the vertical distance of the drogue's equilibrium position relative to the hose root is z, and the heading distance is x.

[0010] Preferably, the basic parameters include hose length l, hose diameter D, hose weight G l , Dred sleeve aerodynamic drag coefficient C D , cone sleeve equivalent aerodynamic area S D , cone sleeve gravity G D , far-field incoming flow true air speed v, aerodynamic viscosity coefficient u corresponding to the flight altitude, and air density ρ.

[0011] Preferably, the aerodynamic force of the cone sleeve is in the direction of the airflow; the aerodynamic pressure difference force direction of the refueling hose is perpendicular to the axis of the hose and upward.

[0012] Preferably, the calculation formula of the drogue aerodynamic force is:

[0013]

[0014] Preferably, the aerodynamic pressure differential force coefficient C of the refueling hose is n The calculation formula is:

[0015]

[0016] Preferably, the calculation formula for the pneumatic pressure difference force of the refueling hose is:

[0017]

[0018] Preferably, the torque balance equation is:

[0019]

[0020] The hose length distance equation is x 2 +z 2 =l 2 .

[0021] As a specific embodiment, a system for calculating the equilibrium position of a drogue in an aircraft soft refueling system includes a basic parameter acquisition module, a drogue aerodynamic force acquisition module, a refueling hose aerodynamic pressure differential force coefficient acquisition module, a refueling hose aerodynamic pressure differential force acquisition module, and an equation solving module. The basic parameter acquisition module is used to determine the basic parameters required for the calculation;

[0022] The drogue aerodynamic force acquisition module is used to determine the direction of the drogue aerodynamic force and calculate the drogue aerodynamic force based on the drogue aerodynamic drag coefficient, drogue equivalent aerodynamic area, far-field incoming flow true air speed, and air density corresponding to the flight altitude in the basic parameters.

[0023] The refueling hose aerodynamic pressure differential force coefficient acquisition module is used to calculate the aerodynamic pressure differential force local Reynolds number Re according to the basic parameters of the hose diameter, far-field incoming flow true air speed, aerodynamic viscosity coefficient corresponding to the flight altitude and air density. p =ρ·v·D / u, and then calculate the aerodynamic pressure differential force coefficient C according to the local Reynolds number of the aerodynamic pressure differential force n ;

[0024] The refueling hose aerodynamic pressure differential force acquisition module is used to determine the direction of the aerodynamic pressure differential force of the refueling hose. Based on the basic parameters of the hose, including hose length, hose diameter, far-field incoming air speed, and air density corresponding to the flight altitude, the aerodynamic pressure differential force of the refueling hose is obtained by assuming that the vertical distance of the drogue equilibrium position relative to the hose root is z and the heading distance is x.

[0025] The equation-solving module is used to obtain the stress state data of the hose-drogue combination in the equilibrium state. The torque balance equation is established by combining the drogue aerodynamic force, the aerodynamic pressure difference force coefficient of the refueling hose, and the aerodynamic pressure difference moment of the refueling hose. The torque balance equation is combined with the hose length and distance equation to obtain a quadratic equation system. By solving the quadratic equation system, the vertical distance z and the heading distance x of the drogue equilibrium position relative to the hose root are obtained.

[0026] Preferably, the basic parameters include hose length l, hose diameter D, hose weight G l , Dred sleeve aerodynamic drag coefficient C D , cone sleeve equivalent aerodynamic area S D , cone sleeve gravity G D , far-field incoming flow true air speed v, aerodynamic viscosity coefficient u corresponding to the flight altitude, and air density ρ.

[0027] Preferably, the aerodynamic force of the cone sleeve is in the direction of the airflow; the aerodynamic pressure difference force direction of the refueling hose is perpendicular to the axis of the hose and upward.

[0028] Preferably, the calculation formula of the drogue aerodynamic force is:

[0029]

[0030] Preferably, the aerodynamic pressure differential force coefficient C of the refueling hose is n The calculation formula is:

[0031]

[0032] Preferably, the calculation formula for the pneumatic pressure difference force of the refueling hose is:

[0033]

[0034] Preferably, the torque balance equation is:

[0035]

[0036] The hose length distance equation is x 2 +z 2 =l 2 .

[0037] The method and system for calculating the equilibrium position of the drogue sleeve of an aircraft soft refueling system disclosed in the present application can quickly calculate the reel rewinding torque of the aircraft soft refueling system based on a small amount of data, avoiding the need for unsteady fluid-solid coupling analysis or programming to establish a mathematical model for solution, greatly reducing the calculation cost and cycle of the drogue sleeve equilibrium position, and providing a simple and universal calculation method for the design of aircraft soft refueling systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions provided by this application, the following is a brief introduction to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application.

[0039] Figure 1 This is a schematic diagram of the overall process of this application;

[0040] Figure 2 This is a schematic diagram of the stress state of the hose-cone sleeve combination in this application. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0042] A method for calculating the equilibrium position of the drogue of an aircraft soft refueling system, such as Figure 1 As shown, the following steps are included:

[0043] Step S100: Determine the basic parameters required for calculation

[0044] Basic parameters include hose length l, hose diameter D, hose weight G l , Dred sleeve aerodynamic drag coefficient C D , cone sleeve equivalent aerodynamic area S D , cone sleeve gravity G D , far-field incoming flow true air speed v, aerodynamic viscosity coefficient u corresponding to the flight altitude, and air density ρ.

[0045] Step S200, calculate the aerodynamic force of the drogue

[0046] Determine the direction of the drogue aerodynamic force and calculate the drogue aerodynamic force based on the basic parameters, including the drogue aerodynamic drag coefficient, the drogue equivalent aerodynamic area, the far-field incoming flow true air speed, and the air density corresponding to the flight altitude.

[0047] Among them, the direction of the drogue aerodynamic force is in the direction of the airflow (that is, the aircraft is heading in the opposite direction).

[0048] The calculation formula of the drogue aerodynamic force is:

[0049]

[0050] Step S300: Calculate the aerodynamic pressure differential force coefficient of the refueling hose

[0051] According to the basic parameters of the hose diameter, the far-field incoming flow true air speed, the aerodynamic viscosity coefficient corresponding to the flight altitude and the air density, the local Reynolds number Re of the aerodynamic pressure difference force is calculated. p =ρ·v·D / u, and then calculate the aerodynamic pressure differential force coefficient C according to the local Reynolds number of the aerodynamic pressure differential force n .

[0052] Pneumatic pressure differential force coefficient C of refueling hose n The calculation formula is:

[0053]

[0054] Step S400: Calculate the pneumatic pressure differential force of the refueling hose

[0055] Determine the direction of the aerodynamic pressure differential force of the refueling hose. Based on the basic parameters of the hose, including hose length, hose diameter, far-field incoming flow true airspeed, and air density corresponding to the flight altitude, and assuming that the vertical distance of the drogue's equilibrium position relative to the hose root is z and the heading distance is x, the aerodynamic pressure differential force of the refueling hose is obtained.

[0056] The direction of the pneumatic pressure difference force of the refueling hose is perpendicular to the hose axis and upward.

[0057] The calculation formula of the pneumatic pressure difference force of the refueling hose is:

[0058]

[0059] Step S500: Solve the simultaneous quadratic equations

[0060] The stress state data of the hose-drogue combination in the equilibrium state are obtained, and the moment balance equation is established by combining the drogue aerodynamic force, the aerodynamic pressure difference force coefficient of the refueling hose, and the aerodynamic pressure difference moment of the refueling hose. The moment balance equation is combined with the hose length and distance equation to obtain a quadratic equation system. By solving the quadratic equation system, the vertical distance z and the heading distance x of the drogue equilibrium position relative to the hose root are obtained.

[0061] Stress state data such as Figure 2 As shown, according to the moment balance, the equation relationship is as follows.

[0062]

[0063] According to the calculation results of the drogue aerodynamic force, the aerodynamic pressure differential force coefficient of the refueling hose, and the aerodynamic pressure differential force of the refueling hose, the moment balance equation is converted to:

[0064]

[0065] The hose length distance equation is x 2 +z 2 =l 2 .

[0066] Through the above design, the reel rewinding torque of the aircraft soft refueling system can be quickly calculated based on a small amount of data, avoiding the need for unsteady fluid-solid coupling analysis or programming to establish a mathematical model for solution, greatly reducing the calculation cost and cycle of the drogue sleeve equilibrium position, and providing a simple and universal calculation method for the design of aircraft soft refueling systems.

[0067] As a specific implementation method, it also includes a cone sleeve equilibrium position calculation system for an aircraft soft refueling system, which adopts the above design and includes a basic parameter acquisition module, a cone sleeve aerodynamic force acquisition module, a refueling hose aerodynamic pressure difference force coefficient acquisition module, a refueling hose aerodynamic pressure difference force acquisition module and an equation solving module.

[0068] The basic parameter acquisition module is used to determine the basic parameters required for calculation;

[0069] The drogue aerodynamic force acquisition module is used to determine the direction of the drogue aerodynamic force and calculate the drogue aerodynamic force based on the drogue aerodynamic drag coefficient, drogue equivalent aerodynamic area, far-field incoming flow true air speed, and air density corresponding to the flight altitude in the basic parameters.

[0070] The refueling hose aerodynamic pressure differential force coefficient acquisition module is used to calculate the aerodynamic pressure differential force local Reynolds number Re according to the basic parameters of the hose diameter, far-field incoming flow true air speed, aerodynamic viscosity coefficient corresponding to the flight altitude and air density. p=ρ·v·D / u, and then calculate the aerodynamic pressure differential force coefficient C according to the local Reynolds number of the aerodynamic pressure differential force n ;

[0071] The refueling hose aerodynamic pressure differential force acquisition module is used to determine the direction of the aerodynamic pressure differential force of the refueling hose. Based on the basic parameters of the hose, including hose length, hose diameter, far-field incoming air speed, and air density corresponding to the flight altitude, the aerodynamic pressure differential force of the refueling hose is obtained by assuming that the vertical distance of the drogue equilibrium position relative to the hose root is z and the heading distance is x.

[0072] The equation-solving module is used to obtain the stress state data of the hose-drogue combination in the equilibrium state. The torque balance equation is established by combining the drogue aerodynamic force, the aerodynamic pressure difference force coefficient of the refueling hose, and the aerodynamic pressure difference moment of the refueling hose. The torque balance equation is combined with the hose length and distance equation to obtain a quadratic equation system. By solving the quadratic equation system, the vertical distance z and the heading distance x of the drogue equilibrium position relative to the hose root are obtained.

[0073] Preferably, the basic parameters include hose length l, hose diameter D, hose weight G l , Dred sleeve aerodynamic drag coefficient C D , cone sleeve equivalent aerodynamic area S D , cone sleeve gravity G D , far-field incoming flow true air speed v, aerodynamic viscosity coefficient u corresponding to the flight altitude, and air density ρ.

[0074] Preferably, the aerodynamic force of the cone sleeve is in the direction of the airflow; the aerodynamic pressure difference force direction of the refueling hose is perpendicular to the axis of the hose and upward.

[0075] Preferably, the calculation formula of the drogue aerodynamic force is:

[0076]

[0077] Preferably, the aerodynamic pressure differential force coefficient C of the refueling hose is n The calculation formula is:

[0078]

[0079] Preferably, the calculation formula for the pneumatic pressure difference force of the refueling hose is:

[0080]

[0081] Preferably, the torque balance equation is:

[0082]

[0083] The hose length distance equation is x 2 +z 2 =l 2 .

[0084] As a specific implementation method, the following is described with a specific example:

[0085] Step S100, hose length l = 22.86m, hose diameter D = 0.067m, hose gravity G l =921N, cone sleeve aerodynamic drag coefficient C D =0.831, cone sleeve equivalent aerodynamic area S D =0.283m 2 , cone sleeve weight G D =295N, assuming that the true air velocity of the far-field incoming flow v = 200m / s, the aerodynamic viscosity coefficient u corresponding to the flight altitude of 8000m is 1.527×10 - 5 kg / (m·s), air density ρ=0.526kg / m 3 .

[0086] Step S200: Calculate and obtain the aerodynamic force of the drogue.

[0087]

[0088] Step S300: Calculate the aerodynamic pressure differential force coefficient.

[0089] Re p =ρ·v·D / u=0.526×200×0.067+1.527÷10 -5 =4.6×10 5

[0090]

[0091] Step S400: Calculate the pneumatic pressure differential force of the refueling hose.

[0092]

[0093] Step S500: List equations for moment balance.

[0094]

[0095] 2474×z+0.5×6.47×22.86×z 2 =295×x+0.5×921×x

[0096] The above formula is consistent with x 2 +z 2 =l 2 The combined equations can be used to obtain a set of quadratic equations with two variables. The vertical distance z = 5.76 m and the heading distance x = 22.12 m of the equilibrium position of the cone sleeve relative to the root of the hose are obtained.

[0097] Finally, it should be noted that the drawings of the embodiments disclosed in the present invention only involve structures related to the embodiments disclosed in the present invention. Other structures can refer to common designs. In the absence of conflicts, the same embodiment and different embodiments of the present invention can be combined with each other.

[0098] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for calculating the equilibrium position of a drogue in an aircraft refueling system, characterized in that: include: Determine the parameters required for calculation; Determine the direction of the drogue aerodynamic force, and calculate the drogue aerodynamic force based on the drogue aerodynamic drag coefficient, drogue equivalent aerodynamic area, far-field incoming flow true air speed, and air density corresponding to the flight altitude in the parameters; calculate the aerodynamic pressure difference force local Reynolds number Re based on the hose diameter, far-field incoming flow true air speed, aerodynamic viscosity coefficient corresponding to the flight altitude and air density in the parameters. p =ρ·v·D / u, and then calculate the aerodynamic pressure differential force coefficient C according to the local Reynolds number of the aerodynamic pressure differential force n ; Determine the direction of the aerodynamic pressure differential force on the refueling hose. Based on the parameters of hose length, hose diameter, far-field incoming air speed, and air density corresponding to the flight altitude, assume that the vertical distance of the drogue's equilibrium position relative to the hose root is z and the heading distance is x, and calculate the aerodynamic pressure differential force on the refueling hose. The stress state data of the hose-drogue combination in the equilibrium state are obtained, and the moment balance equation is established by combining the drogue aerodynamic force, the aerodynamic pressure difference force coefficient of the refueling hose, and the aerodynamic pressure difference moment of the refueling hose. The moment balance equation is combined with the hose length and distance equation to obtain a quadratic equation system. By solving the quadratic equation system, the vertical distance z and the heading distance x of the drogue equilibrium position relative to the hose root are obtained.

2. The method for calculating the equilibrium position of the drogue of an aircraft soft refueling system according to claim 1, characterized in that: Parameters include hose length l, hose diameter D, hose weight G l , Dred sleeve aerodynamic drag coefficient C D , cone sleeve equivalent aerodynamic area S D , cone sleeve gravity G D , far-field incoming flow true air speed v, aerodynamic viscosity coefficient u corresponding to the flight altitude, and air density ρ.

3. The method for calculating the equilibrium position of the drogue of an aircraft soft refueling system according to claim 1, wherein: The direction of the aerodynamic force of the cone sleeve is along the direction of the airflow; the direction of the aerodynamic pressure difference force of the refueling hose is perpendicular to the axis of the hose and upward.

4. The method for calculating the equilibrium position of the drogue of an aircraft soft refueling system according to claim 2, wherein: The calculation formula of the drogue aerodynamic force is:

5. The method for calculating the equilibrium position of the drogue of an aircraft soft refueling system according to claim 2, wherein: Pneumatic pressure differential force coefficient c of refueling hose n The calculation formula is:

6. The method for calculating the equilibrium position of the drogue of an aircraft soft refueling system according to claim 2, wherein: The calculation formula of the pneumatic pressure difference force of the refueling hose is:

7. The method for calculating the equilibrium position of the drogue of an aircraft soft refueling system according to claim 2, wherein: The moment balance equation is: The hose length distance equation is x 2 +z 2 =l 2 .

8. A system for calculating the equilibrium position of a drogue in an aircraft refueling system, using the method according to any one of claims 1 to 7, characterized in that: It includes a parameter acquisition module, a cone sleeve aerodynamic force acquisition module, a refueling hose aerodynamic pressure difference force coefficient acquisition module, a refueling hose aerodynamic pressure difference force acquisition module and an equation solving module; The parameter acquisition module is used to determine the parameters required for calculation; The drogue aerodynamic force acquisition module is used to determine the direction of the drogue aerodynamic force and calculate the drogue aerodynamic force based on the drogue aerodynamic drag coefficient, drogue equivalent aerodynamic area, far-field incoming flow true air speed, and air density corresponding to the flight altitude in the parameters. The refueling hose aerodynamic pressure differential force coefficient acquisition module is used to calculate the aerodynamic pressure differential force local Reynolds number Re according to the hose diameter, far-field incoming flow true air speed, aerodynamic viscosity coefficient corresponding to the flight altitude and air density in the parameters. p =ρ·v·D / u, and then calculate the aerodynamic pressure differential force coefficient c according to the local Reynolds number of the aerodynamic pressure differential force n ; The refueling hose aerodynamic pressure differential force acquisition module is used to determine the direction of the aerodynamic pressure differential force of the refueling hose. Based on the parameters of the hose length, hose diameter, far-field incoming air speed, and air density corresponding to the flight altitude, the aerodynamic pressure differential force of the refueling hose is obtained by assuming that the vertical distance of the drogue equilibrium position relative to the hose root is z and the heading distance is x. The equation-solving module is used to obtain the stress state data of the hose-drogue combination in the equilibrium state. The torque balance equation is established by combining the drogue aerodynamic force, the aerodynamic pressure difference force coefficient of the refueling hose, and the aerodynamic pressure difference moment of the refueling hose. The torque balance equation is combined with the hose length and distance equation to obtain a quadratic equation system. By solving the quadratic equation system, the vertical distance z and the heading distance x of the drogue equilibrium position relative to the hose root are obtained.

9. The aircraft soft refueling system drogue equilibrium position calculation system according to claim 8, characterized in that: Parameters include hose length l, hose diameter D, hose weight G l , Dred sleeve aerodynamic drag coefficient C D , cone sleeve equivalent aerodynamic area S D , cone sleeve gravity G D , far-field incoming flow true air speed v, aerodynamic viscosity coefficient u corresponding to the flight altitude, and air density ρ.

10. The aircraft soft refueling system drogue equilibrium position calculation system according to claim 8, characterized in that: The direction of the aerodynamic force of the cone sleeve is along the direction of the airflow; the direction of the aerodynamic pressure difference force of the refueling hose is perpendicular to the axis of the hose and upward.

11. The aircraft soft refueling system drogue equilibrium position calculation system according to claim 9, characterized in that: The calculation formula of the drogue aerodynamic force is:

12. The aircraft soft refueling system drogue equilibrium position calculation system according to claim 9, characterized in that: Pneumatic pressure differential force coefficient c of refueling hose n The calculation formula is:

13. The aircraft soft refueling system drogue equilibrium position calculation system according to claim 9, characterized in that: The calculation formula of the pneumatic pressure difference force of the refueling hose is:

14. The aircraft soft refueling system drogue equilibrium position calculation system according to claim 9, characterized in that: The moment balance equation is: The hose length distance equation is x 2 +z 3 =l 2 .

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