A rotor induced velocity fast calculation method, device and equipment based on an improved vortex tube wake model and a storage medium

Abstract

Embodiments of the present application provide a kind of based on the quick calculation method of rotor induced velocity of improved vortex tube wake model, device, equipment and storage medium, wherein, method includes: obtaining the first coordinate conversion relationship between the cross vortex local coordinate system of cross vortex unit and the vortex ring local coordinate system of vortex ring unit;Mapping relationship between the cross vortex unit and vortex ring unit is constructed;Determine the mapping rule of the straight vortex segment length;Calculate the vortex ring coordinates of space point P on the vortex ring local coordinate system at vector radius vector;Calculate the cross vortex coordinates of the space point under the cross vortex local coordinate system;Calculate the cross vortex induced velocity of the space point;Based on the mapping rule, the second coordinate conversion relationship and the cross vortex induced velocity, calculate the rotor disc induced velocity of the space point.The present application not only can shorten about 40 times the calculation time, also can avoid the sharp reduction of calculation accuracy.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of aerospace technology, and include, but are not limited to, a method, apparatus, device and storage medium for rapid calculation of rotor induced velocity based on an improved vortex wake model. Background Technology

[0002] The rotor wake model, as a key component of the flight dynamics model, accounts for a large portion of the solution time and consumes a significant portion of the limited computational resources of the real-time simulation system. The shape of the wake structure in the wake model has a decisive influence on the spatial induced velocity distribution, and the method of describing the wake structure has a significant impact on the solution of rotor-induced inflow. Its complexity directly determines the amount of computation required to solve the model. Further simplification of the wake structure is an important way to further improve the solution efficiency of the wake model.

[0003] Currently, commonly used wake models in helicopter maneuvering flight dynamics modeling mainly include augmented dynamic inflow models considering wake distortion, free wake models, viscous eddy particle models, and vortex transport models. The Pitt-Peters dynamic inflow model with augmented wake distortion is widely used due to its simplicity, ease of use, and high computational efficiency. However, it introduces the rotor disk inflow gradient induced by wake distortion and the wake curvature coefficient, which is related to the ratio of the stable pitch angular velocity of the fuselage. Both of these vary under different flight conditions, and there is no unified selection criterion, leading to questions about the model's universality. Furthermore, the model is only used to solve for the induced inflow at the rotor disk and cannot be used to solve for the induced velocity at points outside the rotor disk region, limiting its application scenarios. While free wake models and viscous eddy particle models can capture wake distortion characteristics well, their computational load is high, making real-time simulation difficult.

[0004] The dynamic distortion vortex ring element wake model in related technologies has a relatively fast solution speed, which basically meets the simulation requirements of personal laptops. Even though the vortex ring element has simplified the wake, the calculation of the induced velocity still requires a lot of computing resources and has high hardware requirements. Although it basically meets the real-time simulation calculation requirements on a regular personal PC, the real-time performance still needs to be further improved. Summary of the Invention

[0005] Based on the problems in related technologies, this invention provides a method, apparatus, device, and storage medium for rapid calculation of rotor induced velocity based on an improved vortex wake model. This solves the problem of low computational efficiency in solving rotor induced inflow in existing vortex wake models described by vortex ring elements, thereby meeting the requirements for fast and real-time computational efficiency in real-time flight simulation.

[0006] The technical solution of this invention is implemented as follows:

[0007] This invention provides a method for rapid calculation of rotor induced velocity based on an improved vortex wake model, the method comprising:

[0008] Obtain the first coordinate transformation relationship between the local coordinate system of the vortex grid element and the local coordinate system of the vortex ring element; the vortex grid element is used to characterize the simplified wake structure element, and the vortex grid element includes four straight vortex segments tangent to the vortex ring element.

[0009] Based on the high similarity between the vertical induced velocities of the grid vortex unit and the vortex ring unit at spatial points along the Z-axis, a mapping relationship between the grid vortex unit and the vortex ring unit is constructed.

[0010] When the length of the straight vortex section dominates the induced velocity distribution characteristics of the grid vortex, the mapping law of the length of the straight vortex section is determined according to the mapping relationship.

[0011] Based on the second coordinate transformation relationship between the local coordinate system of the vortex ring and the planar coordinate system of the propeller disk, calculate the vortex ring coordinates of the spatial point P in the local coordinate system of the vortex ring at the radial vector.

[0012] Based on the first coordinate transformation relationship and the vortex ring coordinates, calculate the vortex coordinates of the spatial point in the local coordinate system of the vortex grid.

[0013] Calculate the vortex-induced velocity of the spatial point based on the vortex coordinates.

[0014] Based on the mapping rule, the second coordinate transformation relationship, and the vortex-induced velocity, the propeller disk-induced velocity of the spatial point is calculated.

[0015] This invention provides a device for rapid calculation of rotor induced velocity based on an improved vortex wake model, the device comprising:

[0016] The module is used to obtain the first coordinate transformation relationship between the local coordinate system of the vortex grid element and the local coordinate system of the vortex ring element; the vortex grid element is used to characterize the simplified wake structure element, and the vortex grid element includes four straight vortex segments tangent to the vortex ring element.

[0017] A construction module is used to construct a mapping relationship between the grid vortex unit and the vortex ring unit based on the high similarity characteristics of the vertical induced velocities along the Z-axis at spatial points.

[0018] The determination module is used to determine the mapping law of the straight vortex section length based on the mapping relationship when the length of the straight vortex section is the dominant characteristic of the induced velocity distribution of the grid vortex.

[0019] The calculation module is used to calculate the vortex ring coordinates of the spatial point P in the vortex ring local coordinate system at the radial direction, based on the second coordinate transformation relationship between the vortex ring local coordinate system and the propeller disk plane coordinate system.

[0020] The calculation module is also used to calculate the grid coordinates of the spatial point in the local coordinate system of the grid vortex based on the first coordinate transformation relationship and the vortex ring coordinates;

[0021] The calculation module is also used to calculate the vortex-induced velocity of the spatial point based on the vortex coordinates.

[0022] The calculation module is also used to calculate the propeller disk induced velocity of the spatial point based on the mapping law, the second coordinate transformation relationship, and the vortex induced velocity.

[0023] In some embodiments, the calculation module is further configured to calculate the rotation angle between the grid-like vortex local coordinate system and the vortex local coordinate system based on the vortex ring coordinates; the rotation angle ψ is expressed as:

[0024]

[0025] Where, x VR Let y be the distance of point P in space along the x-axis of the local parallel coordinate system of the vortex ring. VR Let P be the distance of spatial point P along the y-axis of the local parallel coordinate system of the vortex ring.

[0026] In some embodiments, the obtaining module is further configured to determine the local coordinate system O of the tic-tac-toe grid. VL X VL Y VL Z VL and the local coordinate system O of the vortex ring VR X VR Y VR Z VR Located at the center of the vortex ring unit; the vortex ring unit and the grid vortex unit are located in the same plane; the grid vortex is rotated through the central axis of the vortex ring, and the coordinate system X of the grid vortex body is determined. VL Y VL Z VL ZhongX VL The axis and the vertical plane passing through the spatial point and the local X VR -Y VR The intersection lines of the planes coincide, resulting in a rotation angle; based on the rotation angle, the first coordinate transformation relationship is determined; the first coordinate transformation relationship is:

[0027]

[0028] In some embodiments, the second coordinate transformation relationship is expressed as:

[0029]

[0030] Among them, X o With X W Y W The angle between them is the pitch angle θ. y X o The bottom is positive, X o Z o With Z W The angle between them is the side tilt angle θ. x The vortex ring element tilted to the left is positive, X o With X W Z W The included angle is the yaw angle θ. z A leftward deviation is considered positive.

[0031] In some embodiments, the propeller disk plane coordinate system X W Y W Z W With the local coordinate system X of the vortex ring o Y o Z o The propeller disk induced velocity is calculated in the following manner:

[0032]

[0033] in, The transpose represents the coordinate transformation relationship between the local coordinate system of the vortex ring and the plane coordinate system of the propeller disk. This indicates a mapping relationship.

[0034] This invention provides a device for rapidly calculating rotor induced velocity based on an improved vortex wake model, comprising: a memory for storing executable instructions; and a processor for executing the executable instructions stored in the memory to implement the aforementioned method for rapidly calculating rotor induced velocity based on the improved vortex wake model.

[0035] This invention provides a computer-readable storage medium storing executable instructions, which, when executed by a processor, enable the aforementioned method for rapid calculation of rotor induced velocity based on an improved vortex wake model.

[0036] The rotor-induced velocity calculation method based on an improved vortex wake model provided in this invention offers higher computational efficiency compared to numerical calculation models such as free wakes and viscous vortex particles, meeting the needs of real-time simulation. Compared to existing technologies, this invention significantly improves the calculation efficiency of rotor disk-induced inflow by simplifying the wake structure description and employing a fast calculation method. When using a 1° azimuth angle to divide and superimpose the calculation of induced velocities at spatial points in the vortex ring, it not only reduces the calculation time by approximately 40 times but also avoids a significant decrease in calculation accuracy. Furthermore, compared to dynamic inflow models, this invention not only offers slightly better calculation accuracy but can also calculate the induced velocity at any point in space, thereby assisting in the calculation of aerodynamic interference between the rotor and other components, demonstrating high application value. Simultaneously, this calculation method is applicable to various aircraft configurations, requiring no manual selection of model parameters, and exhibits strong versatility. Attached Figure Description

[0037] Figure 1 This is a flowchart illustrating a method for rapid calculation of rotor induced velocity based on an improved vortex wake model, provided by an embodiment of the present invention.

[0038] Figure 2 This is a schematic diagram of the vortex ring unit and the grid vortex unit provided in the embodiments of the present invention;

[0039] Figure 3 This is a schematic diagram of the local coordinate system of the vortex ring and the coordinate system of the vortex body provided in an embodiment of the present invention;

[0040] Figure 4 This is a schematic diagram comparing the shapes of two types of unit wake structures provided in an embodiment of the present invention, where μ = 0.05 is the stable pitch velocity q / Ω = 0.012 during forward flight.

[0041] Figure 5 This is a schematic diagram of the vortex wake model provided in an embodiment of the present invention;

[0042] Figure 6 A schematic diagram of the composition structure of the rotor induced velocity rapid calculation device based on the improved vortex wake model provided in an embodiment of the present invention;

[0043] Figure 7 This is a schematic diagram of the composition of a rotor-induced velocity rapid calculation device based on an improved vortex wake model, provided in an embodiment of the present invention. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. The described embodiments should not be regarded as limitations on the present invention. All other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] In the following description, references to "some embodiments" refer to a subset of all possible embodiments; however, it is understood that "some embodiments" may be the same or different subsets of all possible embodiments and may be combined with each other without conflict. Unless otherwise defined, all technical and scientific terms used in the embodiments of the invention have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiments of the invention pertain. The terminology used in the embodiments of the invention is for the purpose of describing the embodiments of the invention only and is not intended to limit the invention.

[0046] The following describes an exemplary application of the rotor-induced velocity rapid calculation device based on the improved vortex wake model according to embodiments of the present invention. This device can be implemented as a terminal or a server. In one implementation, the device can be implemented as a laptop, tablet, desktop computer, mobile device, or other types of terminal. In another implementation, it can also be implemented as a server. The server can be an independent physical server, a server cluster or distributed system composed of multiple physical servers, or a cloud server providing basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communication, middleware services, domain name services, security services, content delivery networks (CDNs), and big data and artificial intelligence platforms. The terminal and server can be directly or indirectly connected via wired or wireless communication, which is not limited in the embodiments of the present invention. The following describes an exemplary application of the rotor-induced velocity rapid calculation device based on the improved vortex wake model when implemented as a server.

[0047] This invention provides a method for rapid calculation of rotor induced velocity based on an improved vortex wake model. See [link to relevant documentation]. Figure 1 , Figure 1 This is a flowchart illustrating a rapid calculation method for rotor induced velocity based on an improved vortex wake model provided by an embodiment of the present invention. Figure 1 The steps shown are explained.

[0048] Step S210: Obtain the first coordinate transformation relationship between the local coordinate system of the grid vortex element and the local coordinate system of the vortex ring element.

[0049] Here, the grid vortex unit is used to characterize the simplified wake structure unit, which includes four straight vortex segments tangent to the vortex ring unit.

[0050] In some embodiments, four straight vortex segments tangent to the circular vortex ring are used to simulate or simplify the wake structure or description method of the circular vortex ring unit. Each straight vortex segment is perpendicular to the others, forming a grid-shaped grid vortex unit (e.g., Figure 2 As shown in the figure, it has a centrally symmetric structure. For ease of description, the simplified wake structure element will be referred to as the grid vortex element in this paper.

[0051] To facilitate the description of the wake structure geometry and the rapid calculation method for spatial point-induced velocities introduced in this paper, the local coordinate system O of the grid vortex will be used first. VL X VL Y VL Z VL With the local coordinate system O of the vortex ring VR X VR Y VR Z VR The coordinate transformation relationship between them. Figure 3 Local coordinate system O of the middle vortex ring VR X VR Y VR Z VR and the local coordinate system O of the grid vortex VL X VL Y VL Z VL The origin of each vortex is located at the center of the vortex ring, and the vortex ring and the grid vortex lie in the same plane. When calculating the induced velocity of a spatial point P in the local vortex ring coordinate system, it is necessary to rotate the grid vortex around the central axis of the vortex ring until the grid vortex body coordinate system X... VL Y VL Z VL X in VL The axis and the vertical plane passing through point P and the local X VR -Y VR When the lines of intersection of the planes coincide, the angle of rotation can be represented by ψ. This coordinate transformation relationship can be expressed as:

[0052]

[0053] Step S220: Based on the high similarity between the vertical induced velocities of the grid vortex unit and the vortex ring unit at spatial points along the Z-axis, a mapping relationship is constructed between the grid vortex unit and the vortex ring unit.

[0054] In some embodiments, the grid vortex element is a simplified replacement for the vortex ring element. The requirement is that when calculating the induced velocity at a specified spatial point, the induced velocity results calculated by the grid vortex element and the vortex ring element are infinitely close, in order to simulate the effect of the vortex ring element. The vertical induced velocity distribution along the Z-axis at the computational node is highly similar between a grid vortex composed of infinitely long straight vortex segments and a vortex ring of unit radius. Based on this property, a mapping relationship between the grid vortex element and the vortex ring element is constructed at the numerical level.

[0055] Step S230: When the length of the straight vortex section dominates the induced velocity distribution characteristics of the grid vortex, determine the mapping law of the length of the straight vortex section according to the mapping relationship.

[0056] In some embodiments, the variable parameters for the straight vortex segment are the straight vortex segment length L and the circulation intensity Γ. To simplify the calculation of the structural model, the variable parameters of the grid vortex element are set to use the same circulation intensity Γ and length L for the four straight vortex segments. As the height H increases, the straight vortex segment length L will dominate the grid vortex-induced velocity distribution characteristics as a parameter. Figure 4 This demonstrates the mapping relationship between the length L of the straight vortex section and the height.

[0057] In some embodiments, the mapping curve can be fitted using methods such as surrogate models. In this invention, the Dirichlet function from the family of auxiliary functions of the delta function is selected for fitting. Then, as the height H of the computational space point from the vortex ring plane increases, the mapping law of the straight vortex segment length L can be characterized as follows:

[0058]

[0059] Step S240: Calculate the vortex ring coordinates of spatial point P in the vortex ring local coordinate system at the radial distance, based on the second coordinate transformation relationship between the vortex ring local coordinate system and the propeller disk plane coordinate system.

[0060] In some embodiments, the induced flow fields of the grid vortex element and the vortex ring element exhibit good consistency within the symmetry plane. Although this is a local property, it can be extended to the entire space by leveraging the symmetry of the spatially induced flow field of the equal-circulation vortex ring element. The key point is that the grid vortex element needs to be rotated around the axis of the vortex ring element when calculating the induced velocity. In the propeller disk plane coordinate system O... W X W Y W Z W Fast calculation of spatial point P(x) p ,y p ,z p The method is as follows:

[0061] In some embodiments, the coordinates of point P are transferred from the propeller plane coordinate system O. W XW Y W Z W The description is transformed to the origin in the radius vector R. VR The vector from the origin of the propeller disk plane coordinate system to the center point of the vortex ring coordinate system in the local coordinate system O of the vortex ring. VR X VR Y VR Z VR The description requires moving the origin of the coordinate system and rotating the coordinate system. The coordinates of the above spatial point in the local coordinate system of the vortex ring can be expressed as:

[0062]

[0063] Among them, R VR It is the vector from the origin of the propeller disk plane coordinate system to the center point of the vortex ring coordinate system.

[0064] In some embodiments, the calculation may also include the rotation angle ψ between the vortex ring local coordinate system and the grid vortex local coordinate system:

[0065]

[0066] Where, x VR Let y be the distance of point P in space along the x-axis of the local parallel coordinate system of the vortex ring. VR Let P be the distance of spatial point P along the y-axis of the local parallel coordinate system of the vortex ring.

[0067] Step S250: Based on the first coordinate transformation relationship and the vortex ring coordinates, calculate the vortex coordinates of the spatial point in the local coordinate system of the vortex.

[0068] In some embodiments, the grid vortex is rotated around the central axis of the vortex ring until the grid vortex body coordinate system X... VL Y VL Z VL X in VL The axis and the vertical plane passing through point P and the local X VR Y VR The lines of intersection of the planes coincide. Calculate the coordinates P(x) of the vortex in the local coordinate system. VL ,y VL ,z VL The vortex coordinate system of this grid is represented as follows:

[0069]

[0070] Step S260: Calculate the vortex-induced velocity of the spatial point based on the vortex coordinates.

[0071] In some embodiments, the induced velocity of the vortex element is calculated based on the vortex coordinates.

[0072] Among them, T VR2VL This indicates the coordinate transformation relationship between the local coordinate system of the vortex ring and the local coordinate system of the grid vortex.

[0073] Step S270: Calculate the propeller disk induced velocity of the spatial point based on the mapping rule, the second coordinate transformation relationship, and the vortex induced velocity.

[0074] In some embodiments, the induced velocity in the local coordinate system of the vortex pattern is transformed to the propeller disk plane coordinate system to obtain the propeller disk induced velocity:

[0075]

[0076] In some embodiments, step S210 can be determined in the following ways:

[0077] First, determine the local coordinate system O of the grid vortex. VL X VL Y VL Z VL and the local coordinate system O of the vortex ring VR X VR Y VR Z VR Located at the center of the vortex ring unit; the vortex ring unit and the grid vortex unit are located in the same plane. Next, the grid vortex is rotated through the central axis of the vortex ring, and the coordinate system X of the grid vortex body is... VL Y VL Z VL ZhongX VL The axis and the vertical plane passing through the spatial point and the local X VR -Y VR The intersection lines of the planes coincide, resulting in a rotation angle. Finally, based on the rotation angle, the first coordinate transformation relationship is determined; the first coordinate transformation relationship is:

[0078]

[0079] In some embodiments, the second coordinate transformation relationship is expressed as:

[0080]

[0081] Among them, X o With X W Y W The angle between them is the pitch angle θ. y X o The bottom is positive, X o Z o With Z W The angle between them is the side tilt angle θ. x The vortex ring element tilted to the left is positive, X oWith X W Z W The included angle is the yaw angle θ. z A leftward deviation is considered positive.

[0082] The rotor-induced velocity calculation method based on an improved vortex wake model provided in this invention offers higher computational efficiency compared to numerical calculation models such as free wakes and viscous vortex particles, meeting the needs of real-time simulation. Compared to existing technologies, this invention significantly improves the calculation efficiency of rotor disk-induced inflow by simplifying the wake structure description and employing a fast calculation method. When using a 1° azimuth angle to divide and superimpose the calculation of induced velocities at spatial points in the vortex ring, it not only reduces the calculation time by approximately 40 times but also avoids a significant decrease in calculation accuracy. Furthermore, compared to dynamic inflow models, this invention not only offers slightly better calculation accuracy but can also calculate the induced velocity at any point in space, thereby assisting in the calculation of aerodynamic interference between the rotor and other components, demonstrating high application value. Simultaneously, this calculation method is applicable to various aircraft configurations, requiring no manual selection of model parameters, and exhibits strong versatility.

[0083] The following will describe an exemplary application of the embodiments of the present invention in a practical application scenario.

[0084] vortex wake model (e.g.) Figure 5 The image shown is a classic wake model. The vorticity generated by the rotor forms a continuous tubular vortex tube that extends backward, constituting the outer surface of the rotor wake. The vortex tube model is suitable for analyzing various flight conditions. The calculation of the induced velocity in space using the vortex tube wake structure generally employs numerical methods. This involves discretizing the vortex tube along its centerline into multiple vortex ring elements perpendicular to the centerline, calculating the induced velocity at each spatial point using the Biot-Savart law, and finally superimposing the results. Further simplification of the vortex ring elements can effectively improve the solution speed of the vortex tube wake model, or other wake models described by vortex ring elements.

[0085] The purpose of this invention is to provide a new simplified description method and a fast calculation method for wake structures, so as to solve the problem of low calculation efficiency of rotor-induced inflow solution in the existing vortex ring unit-described vortex tube wake model, and to meet the requirements of fast and real-time calculation efficiency for real-time flight simulation.

[0086] This invention uses four straight vortex segments 1.1, 1.2, 1.3, and 1.4, tangent to a circular vortex ring, to simulate and simplify the wake structure or description method based on a circular vortex ring unit. Each straight vortex segment is perpendicular to the others, forming a grid-shaped "grid-vortex" unit (e.g., ...). Figure 2 As shown, it has a centrally symmetric structure. The grid vortex, as a method for describing the wake structure, can replace vortex ring element 2 in describing the wake structure; changes in the size of the grid vortex will simulate the distortion of vortex ring element 2.

[0087] This invention proposes a simplified description method for the wake structure under C T =0.005, μ=0.05, stable pitch velocity q / Ω=0.012 during forward flight. Comparison of the wake geometry of the vortex tube wake model described by the vortex ring element and the "grid vortex" element.

[0088] To demonstrate the computational efficiency of the proposed rapid rotor induced velocity calculation method based on the improved vortex wake model, the following calculations will compare the proposed simplified wake structure description and rapid calculation method with the conventional calculation method for circular vortex wake structures under classic vortex wakes with wake inclination angles χ of 0°, 30°, 45°, and 60°. The wake inclination angle is calculated using the following formula:

[0089] χ=arctan(μλ) (9).

[0090] In some embodiments, the method for calculating the induced velocity in space by the circular vortex ring element is to use a 1° azimuth angle as the discretization step size, use 360 ​​straight vortex segments to discretize the circular vortex ring element into polygonal elements, then use the Biot-Savart law to calculate the induced velocity at the midpoint in space for each straight vortex segment, and then superimpose the calculation results of all straight vortex segments to obtain the final induced velocity result.

[0091] In this example, 360 computational nodes are evenly distributed on the rotor disk. The induced velocity at each point is calculated to obtain the induced velocity distribution at the rotor disk. The induced inflow distribution characteristics of the rotor, i.e., the inflow coefficients λ0 and λ, are obtained using existing mature methods. 1c ,λ 1s The non-uniform inflow to the propeller disk can be expressed by the above coefficients as follows:

[0092]

[0093] in, Let denot be the dimensionless radius of the blade, and ψ represent the azimuth angle. Table 1 shows the relative errors of different description methods and calculation methods under different wake inclination angles:

[0094] Table 1 Comparison of Inflow Coefficient Identification Results under Stable Flight Conditions

[0095]

[0096] Continued from Table 1: Comparison of Inflow Coefficient Identification Results under Stable Flight Conditions

[0097]

[0098] Table 2 Comparison of propeller disk inflow calculation time under stable flight conditions

[0099]

[0100] The inflow coefficient identification results show that the disc-induced inflow identification results of the vortex ring unit and the grid vortex unit under stable flight conditions have relatively small deviations, not exceeding 5% in the test, and the calculation results have good consistency. However, the calculation time on a personal laptop equipped with an AMD Ryzen 7 4800-H CPU shows that the new simplified description method and fast calculation method of the wake structure proposed in this invention reduces the calculation time by about 40 times compared with the vortex tube model described by the vortex ring, fully meeting the real-time simulation calculation efficiency requirements of engineering, with high computational efficiency and significant application value.

[0101] The rotor-induced velocity calculation method based on an improved vortex wake model provided in this invention offers higher computational efficiency compared to numerical calculation models such as free wakes and viscous vortex particles, meeting the needs of real-time simulation. Compared to existing technologies, this invention significantly improves the calculation efficiency of rotor disk-induced inflow by simplifying the wake structure description and employing a fast calculation method. When using a 1° azimuth angle to divide and superimpose the calculation of induced velocities at spatial points in the vortex ring, it not only reduces the calculation time by approximately 40 times but also avoids a significant decrease in calculation accuracy. Furthermore, compared to dynamic inflow models, this invention not only offers slightly better calculation accuracy but can also calculate the induced velocity at any point in space, thereby assisting in the calculation of aerodynamic interference between the rotor and other components, demonstrating high application value. Simultaneously, this calculation method is applicable to various aircraft configurations, requiring no manual selection of model parameters, and exhibits strong versatility.

[0102] Figure 6 This is a schematic diagram of the composition structure of the rotor-induced velocity rapid calculation device based on the improved vortex wake model provided in an embodiment of the present invention, as shown below. Figure 6As shown, the rotor induced velocity rapid calculation device 600 based on the improved vortex wake model includes: an acquisition module 601, used to obtain the first coordinate transformation relationship between the local coordinate system of the vortex array of the vortex array unit and the local coordinate system of the vortex ring unit; the vortex array unit is used to characterize the simplified wake structure unit, and the vortex array unit includes four straight vortex segments tangent to the vortex ring unit; a construction module 602, used to construct the mapping relationship between the vortex array unit and the vortex ring unit based on the high similarity characteristics of the vertical induced velocities along the Z-axis at spatial points of the vortex array unit and the vortex ring unit; and a determination module 603, used to determine the vortex induced velocity distribution characteristics when the length of the straight vortex segment dominates, based on the... The mapping relationship determines the mapping law for the length of the straight vortex section; the calculation module 604 is used to calculate the vortex ring coordinates of the spatial point P in the vortex ring local coordinate system at the radial direction according to the second coordinate transformation relationship between the vortex ring local coordinate system and the propeller disk plane coordinate system; the calculation module 604 is also used to calculate the grid vortex coordinates of the spatial point in the grid vortex local coordinate system based on the first coordinate transformation relationship and the vortex ring coordinates; the calculation module 604 is also used to calculate the grid vortex induced velocity of the spatial point according to the grid vortex coordinates; the calculation module 604 is also used to calculate the propeller disk induced velocity of the spatial point based on the mapping law, the second coordinate transformation relationship and the grid vortex induced velocity.

[0103] In some embodiments, the calculation module 604 is further configured to calculate the rotation angle between the grid-like vortex local coordinate system and the vortex local coordinate system based on the vortex ring coordinates; the rotation angle ψ is expressed as:

[0104]

[0105] Where, x VR Let y be the distance of point P in space along the x-axis of the local parallel coordinate system of the vortex ring. VR Let P be the distance of spatial point P along the y-axis of the local parallel coordinate system of the vortex ring.

[0106] In some embodiments, the obtaining module 601 is further configured to determine the local coordinate system O of the grid vortex. VL X VL Y VL Z VL and the local coordinate system O of the vortex ring VR X VR Y VR Z VR Located at the center of the vortex ring unit; the vortex ring unit and the grid vortex unit are located in the same plane; the grid vortex is rotated through the central axis of the vortex ring, and the coordinate system X of the grid vortex body is determined. VL Y VL ZVL ZhongX VL The axis and the vertical plane passing through the spatial point and the local X VR -Y VR The intersection lines of the planes coincide, resulting in a rotation angle; based on the rotation angle, the first coordinate transformation relationship is determined; the first coordinate transformation relationship is:

[0107]

[0108] In some embodiments, the second coordinate transformation relationship is expressed as:

[0109]

[0110] Among them, X o With X W Y W The angle between them is the pitch angle θ. y X o The bottom is positive, X o Z o With Z W The angle between them is the side tilt angle θ. x The vortex ring element tilted to the left is positive, X o With X W Z W The included angle is the yaw angle θ. z A leftward deviation is considered positive.

[0111] In some embodiments, the propeller disk plane coordinate system X W Y W Z W With the local coordinate system X of the vortex ring o Y o Z o The propeller disk induced velocity is calculated in the following manner:

[0112]

[0113] in, The transpose represents the coordinate transformation relationship between the local coordinate system of the vortex ring and the plane coordinate system of the propeller disk. This indicates a mapping relationship.

[0114] It should be noted that the description of the apparatus in this embodiment is similar to that of the method embodiment described above, and has similar beneficial effects, therefore it will not be repeated. For technical details not disclosed in this apparatus embodiment, please refer to the description of the method embodiment of this invention for understanding.

[0115] It should be noted that, in the embodiments of the present invention, if the above-described method for rapid calculation of rotor induced velocity based on the improved vortex wake model is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the embodiments of the present invention, or the part that contributes to related technologies, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a terminal to execute all or part of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a magnetic disk, or an optical disk. Thus, the embodiments of the present invention are not limited to any specific hardware and software combination.

[0116] Correspondingly, embodiments of the present invention provide a rapid calculation device for rotor induced velocity based on an improved vortex wake model. Figure 7 This is a schematic diagram of the composition structure of the rotor-induced velocity rapid calculation device based on the improved vortex wake model provided in an embodiment of the present invention, as shown below. Figure 7 As shown, the rotor-induced velocity rapid calculation device 700 based on the improved vortex wake model includes at least: a processor 701 and a computer-readable storage medium 702 configured to store executable instructions, wherein the processor 701 generally controls the overall operation of the rotor-induced velocity rapid calculation device 700 based on the improved vortex wake model. The computer-readable storage medium 702 is configured to store instructions and applications executable by the processor 701, and can also cache data to be processed or processed by various modules in the processor 701 and the rotor-induced velocity rapid calculation device 700 based on the improved vortex wake model, which can be implemented by flash memory or random access memory (RAM).

[0117] This invention provides a storage medium storing executable instructions. When these executable instructions are executed by a processor, they cause the processor to perform the method provided in this invention, for example... Figure 1 The method shown.

[0118] In some embodiments, the storage medium may be a computer-readable storage medium, such as a ferromagnetic random access memory (FRAM), a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), flash memory, magnetic surface memory, optical disc, or a compact disk-read-only memory (CD-ROM); or it may be a device that includes one or any combination of the above-mentioned memories.

[0119] In some embodiments, executable instructions may take the form of a program, software, software module, script, or code, written in any form of programming language (including compiled or interpreted languages, or declarative or procedural languages), and may be deployed in any form, including as a standalone program or as a module, component, subroutine, or other unit suitable for use in a computing environment.

[0120] As an example, executable instructions may, but do not necessarily, correspond to files in a file system. They may be stored as part of a file containing other programs or data, for example, in one or more scripts within a Hyper Text Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple co-located files (e.g., files storing one or more modules, subroutines, or code sections). As an example, executable instructions may be deployed to execute on a single electronic device, or on multiple electronic devices located in one location, or on multiple electronic devices distributed across multiple locations and interconnected via a communication network.

[0121] The above description is merely an embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and scope of the present invention are included within the scope of protection of the present invention.

[0122] It should be understood that the phrase "one embodiment" or "an embodiment" throughout the specification means that a specific feature, structure, or characteristic related to the embodiment is included in at least one embodiment of the invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It should be understood that in the various embodiments of the invention, the sequence numbers of the above-described processes do not imply a sequential order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the invention. The sequence numbers of the above-described embodiments of the invention are merely descriptive and do not represent the superiority or inferiority of the embodiments.

[0123] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. In the several embodiments provided by this invention, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods, such as: multiple units or components may be combined, or integrated into another system, or some features may be ignored or not performed.

[0124] The above description is merely an embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for rapid calculation of rotor induced velocity based on an improved vortex wake model, characterized in that, The method includes: Obtain the first coordinate transformation relationship between the local coordinate system of the vortex grid element and the local coordinate system of the vortex ring element; the vortex grid element is used to characterize the simplified wake structure element, and the vortex grid element includes four straight vortex segments tangent to the vortex ring element. Based on the high similarity between the vertical induced velocities of the grid vortex unit and the vortex ring unit at spatial points along the Z-axis, a mapping relationship between the grid vortex unit and the vortex ring unit is constructed. When the length of the straight vortex section dominates the induced velocity distribution characteristics of the grid vortex, the mapping law of the length of the straight vortex section is determined according to the mapping relationship. Based on the second coordinate transformation relationship between the local coordinate system of the vortex ring and the planar coordinate system of the propeller disk, calculate the vortex ring coordinates of the spatial point P in the local coordinate system of the vortex ring at the radial vector. Based on the first coordinate transformation relationship and the vortex ring coordinates, calculate the vortex coordinates of the spatial point in the local coordinate system of the vortex grid. Calculate the vortex-induced velocity of the spatial point based on the vortex coordinates. Based on the mapping rule, the second coordinate transformation relationship, and the vortex-induced velocity, the propeller disk-induced velocity of the spatial point is calculated.

2. The method according to claim 1, characterized in that, The method further includes: Based on the vortex ring coordinates, calculate the rotation angle between the local coordinate system of the grid vortex and the local coordinate system of the vortex ring; the rotation angle ψ is expressed as: Where, x VR Let y be the distance of point P in space along the x-axis of the local parallel coordinate system of the vortex ring. VR Let P be the distance of spatial point P along the y-axis of the local parallel coordinate system of the vortex ring.

3. The method according to claim 2, characterized in that, The first coordinate transformation relationship between the local coordinate system of the grid vortex element and the local coordinate system of the vortex ring element includes: Determine the local coordinate system O of the grid vortex. VL X VL Y VL Z VL and the local coordinate system O of the vortex ring VR X VR Y VR Z VR Located at the center of the vortex ring unit; the vortex ring unit and the grid vortex unit are located in the same plane; Rotate the grid-like vortex along the central axis of the vortex ring, and set the X coordinate system of the grid-like vortex body. VL Y VL Z VL ZhongX VL The axis and the vertical plane passing through the spatial point and the local X VR -Y VR When the lines of intersection of the planes coincide, the rotation angle is obtained; Based on the rotation angle, the first coordinate transformation relationship is determined; the first coordinate transformation relationship is:

4. The method according to claim 1, characterized in that, The second coordinate transformation relationship is expressed as follows: Among them, X o With X W Y W The angle between them is the pitch angle θ. y X o The bottom is positive, X o Z o With Z W The angle between them is the side tilt angle θ. x The vortex ring element tilted to the left is positive, X o With X W Z W The included angle is the yaw angle θ. z A leftward deviation is considered positive.

5. The method according to claim 1, characterized in that, The propeller disk plane coordinate system X W Y W Z W With the local coordinate system X of the vortex ring o Y o Z o The propeller disk induced velocity is calculated in the following manner: in, The transpose represents the coordinate transformation relationship between the local coordinate system of the vortex ring and the plane coordinate system of the propeller disk. This indicates a mapping relationship.

6. A rapid calculation device for rotor induced velocity based on an improved vortex wake model, characterized in that, The device includes: The module is used to obtain the first coordinate transformation relationship between the local coordinate system of the vortex grid element and the local coordinate system of the vortex ring element; the vortex grid element is used to characterize the simplified wake structure element, and the vortex grid element includes four straight vortex segments tangent to the vortex ring element. A construction module is used to construct a mapping relationship between the grid vortex unit and the vortex ring unit based on the high similarity characteristics of the vertical induced velocities along the Z-axis at spatial points. The determination module is used to determine the mapping law of the straight vortex section length based on the mapping relationship when the length of the straight vortex section is the dominant characteristic of the induced velocity distribution of the grid vortex. The calculation module is used to calculate the vortex ring coordinates of the spatial point P in the vortex ring local coordinate system at the radial direction, based on the second coordinate transformation relationship between the vortex ring local coordinate system and the propeller disk plane coordinate system. The calculation module is also used to calculate the grid coordinates of the spatial point in the local coordinate system of the grid vortex based on the first coordinate transformation relationship and the vortex ring coordinates; The calculation module is also used to calculate the vortex-induced velocity of the spatial point based on the vortex coordinates. The calculation module is also used to calculate the propeller disk induced velocity of the spatial point based on the mapping law, the second coordinate transformation relationship, and the vortex induced velocity.

7. A rapid calculation device for rotor induced velocity based on an improved vortex wake model, characterized in that, include: Memory, used to store executable instructions; The processor, when executing executable instructions stored in the memory, implements the method for rapid calculation of rotor induced velocity based on the improved vortex wake model as described in any one of claims 1 to 5.

8. A computer-readable storage medium storing executable instructions for causing a processor to execute the executable instructions to implement the rotor induced velocity rapid calculation method based on the improved vortex wake model as described in any one of claims 1 to 5.

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