Rotor induced velocity rapid calculation method, device and equipment based on improved vortex tube wake model and storage medium

Abstract

The embodiment of the invention provides a rotor induced velocity rapid calculation method and device based on an improved vortex tube wake model, equipment and a storage medium, and the method comprises the steps: obtaining a first coordinate conversion relation between a #-shaped vortex local coordinate system of a #-shaped vortex unit and a vortex ring local coordinate system of a vortex ring unit; constructing a mapping relation between the #-shaped vortex units and the vortex ring units; determining a mapping rule of the length of the straight vortex section; calculating a vortex ring coordinate of the space point P on the local coordinate system of the vortex ring at the vector radial vector; calculating a #-shaped vortex coordinate of the space point in a #-shaped vortex local coordinate system; calculating the #-shaped vortex induced velocity of the spatial point; and based on the mapping rule, the second coordinate conversion relation and the #-shaped vortex induced velocity, calculating the disc induced velocity of the spatial point. According to the method, the calculation time can be shortened by about 40 times, and the calculation precision can be prevented from being greatly reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of aviation technology, and relate to but are not limited to a method, device, equipment and storage medium for quickly calculating rotor induced speed based on an improved vortex tube wake model. Background Art

[0002] As a key component of the flight dynamics model, the rotor wake model takes up most of the time required to solve the entire model and consumes the limited computing 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. The description method of the wake structure has an important influence on the solution of the rotor induced inflow. Its complexity directly determines the amount of calculation required to solve the model. Further simplification of the wake structure is an important way to further improve the efficiency of the wake model solution.

[0003] The commonly used wake models in the current helicopter maneuver flight dynamics modeling mainly include the augmented dynamic inflow model considering wake distortion, the free wake model, the viscous vortex particle model, and the vorticity transport model. The Pitt-Peters dynamic inflow model with augmented wake distortion is widely used because of its simplicity, ease of use, and high computational efficiency. However, due to the introduction of the disc inflow gradient induced by the wake distortion and the wake curvature coefficient related to the ratio of the stable pitch angular velocity of the fuselage, both of which are different under different flight conditions and there is no unified selection standard, resulting in doubts about the universality of the model. In addition, the model is only used to solve the induced inflow at the disc, and cannot be used to solve the induced velocity of the space point outside the disc area, so the application scenario is limited. Although the free wake model and the viscous vortex particle model can better capture the characteristics of the wake distortion, their calculation amount is large and it is difficult to achieve real-time simulation.

[0004] The dynamic distortion vortex ring unit wake model in the related technology has a fast solution speed and basically meets the requirements of personal laptop simulation. Even though the vortex ring unit has simplified the wake, the calculation of the induced velocity still consumes a lot of computing resources and has high requirements for hardware. Although it basically meets the real-time simulation calculation requirements on a conventional personal PC, the real-time performance needs to be further improved. Summary of the invention

[0005] Based on the problems in the related art, an embodiment of the present invention provides a method, device, equipment and storage medium for quickly calculating the rotor induced velocity based on an improved vortex tube wake model, so as to solve the problem of low computational efficiency of solving the rotor induced inflow in the vortex tube wake model described by the existing vortex ring unit, thereby meeting the fast and real-time computational efficiency requirements of real-time flight simulation.

[0006] The technical solution of the embodiment of the present invention is achieved as follows:

[0007] An embodiment of the present invention provides a method for quickly calculating rotor induced speed based on an improved vortex tube wake model, the method comprising:

[0008] Obtaining a first coordinate conversion relationship between a local coordinate system of a tic-tac-toe vortex of a tic-tac-toe vortex unit and a local coordinate system of a vortex ring of a vortex ring unit; the tic-tac-toe vortex unit is used to characterize a simplified wake structure unit, and the tic-tac-toe vortex unit includes four straight vortex segments tangent to the vortex ring unit;

[0009] According to the high similarity characteristics of the Z-axis vertical induced velocity of the tic-tac-toe vortex unit and the vortex ring unit at the spatial point, a mapping relationship between the tic-tac-toe vortex unit and the vortex ring unit is constructed;

[0010] In the case where the length of the straight vortex section dominates the tic-tac-toe vortex induced velocity distribution characteristics, the mapping law of the length of the straight vortex section is determined according to the mapping relationship;

[0011] Calculating the vortex ring coordinates of the spatial point P on the vortex ring local coordinate system at the radial vector according to a second coordinate transformation relationship between the vortex ring local coordinate system and the disk plane coordinate system;

[0012] Based on the first coordinate transformation relationship and the vortex ring coordinates, calculating the tic-tac-toe vortex coordinates of the spatial point in the tic-tac-toe vortex local coordinate system;

[0013] Calculating the tic-tac-toe vortex induced velocity of the spatial point according to the tic-tac-toe vortex coordinates;

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

[0015] An embodiment of the present invention provides a device for quickly calculating rotor induced speed based on an improved vortex tube wake model, the device comprising:

[0016] An acquisition module is used to obtain a first coordinate conversion relationship between a local coordinate system of a tic-tac-toe vortex of a tic-tac-toe vortex unit and a local coordinate system of a vortex ring of a vortex ring unit; the tic-tac-toe vortex unit is used to characterize a simplified wake structure unit, and the tic-tac-toe vortex unit includes four straight vortex segments tangent to the vortex ring unit;

[0017] A construction module, for constructing a mapping relationship between the tic-tac-toe vortex unit and the vortex ring unit according to the high similarity characteristics of the Z-axis vertical induced velocities of the tic-tac-toe vortex unit and the vortex ring unit at a spatial point;

[0018] A determination module, for determining the mapping rule of the straight vortex section length according to the mapping relationship when the straight vortex section length is the dominant factor in the tic-tac-toe vortex induced velocity distribution characteristic;

[0019] A calculation module, used for calculating the vortex ring coordinates of the spatial point P on the vortex ring local coordinate system at the radial vector according to a second coordinate transformation relationship between the vortex ring local coordinate system and the disk plane coordinate system;

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

[0021] The calculation module is further used to calculate the tic-tac-toe vortex induced velocity of the spatial point according to the tic-tac-toe vortex coordinates;

[0022] The calculation module is further used to calculate the propeller disk induced velocity of the spatial point based on the mapping rule, the second coordinate transformation relationship and the tic-tac-toe vortex induced velocity.

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

[0024]

[0025] Among them, x VR is the distance of the spatial point P in the x-axis direction of the local parallel coordinate system of the vortex ring, y VR It is the distance of the spatial point P in the y-axis direction of the local parallel coordinate system of the vortex ring.

[0026] In some embodiments, the acquisition module is further used to determine the local coordinate system of the tic-tac-toe vortex. VL X VL Y VL Z VL and the vortex ring local coordinate system O VR X VR Y VR Z VR Located at the center of the vortex ring unit; the vortex ring unit and the well-shaped vortex unit are located in the same plane; the well-shaped vortex is rotated by the central axis of the vortex ring to change the well-shaped vortex body coordinate system X VL Y VL Z VL Medium X 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 to obtain 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 Positive below, X o Z o With Z W The angle between is the roll angle θ x , the left side of the vortex ring unit is positive, X o With X W Z W The angle between the two is the yaw angle θ z , deflection to the left is positive.

[0031] In some embodiments, the propeller disc plane coordinate system X W Y W Z W The local coordinate system X of the vortex ring o Y o Z o The propeller disc induced velocity is calculated by:

[0032]

[0033] in, represents the transposition of the coordinate transformation relationship between the vortex ring local coordinate system and the disk plane coordinate system, Indicates a mapping relationship.

[0034] An embodiment of the present invention provides a device for quickly calculating the rotor induced speed based on an improved vortex tube wake model, comprising: a memory for storing executable instructions; and a processor for implementing the above-mentioned method for quickly calculating the rotor induced speed based on the improved vortex tube wake model when executing the executable instructions stored in the memory.

[0035] An embodiment of the present invention provides a computer-readable storage medium storing executable instructions for causing a processor to execute the executable instructions to implement the above-mentioned method for quickly calculating rotor induced speed based on the improved vortex tube wake model.

[0036] The embodiment of the present invention provides a method for quickly calculating the rotor induced velocity based on the improved vortex tube wake model. Compared with numerical calculation models such as free wakes and viscous vortex particles, the method provided by the present invention has high calculation efficiency and can meet the needs of real-time simulation. Compared with the prior art, the present invention greatly improves the calculation efficiency of the induced inflow of the impeller disk after simplifying the description of the wake structure and applying a fast calculation method. When the vortex ring uses 1° azimuth angle division to superimpose the calculation of the induced velocity of the spatial point, it can not only shorten the calculation time by about 40 times, but also avoid a significant reduction in the calculation accuracy. In addition, compared with the dynamic inflow model, the present invention is not only slightly better in calculation accuracy, but also can calculate the induced velocity of any point in space, thereby assisting in the calculation of the aerodynamic interference between the rotor and other components, and has a high application value. At the same time, the calculation method is also applicable to various aircraft configurations, without the need to manually select model parameters, and has strong versatility. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a flow chart of a method for quickly calculating rotor induced speed based on an improved vortex tube wake model provided by an embodiment of the present invention;

[0038] Figure 2 Schematic diagram of a vortex ring unit and a tic-tac-toe vortex unit provided in an embodiment of the present invention;

[0039] Figure 3 The embodiment of the present invention provides a schematic diagram of the vortex ring local coordinate system and the tic-tac-toe vortex body coordinate system;

[0040] Figure 4 It is a schematic diagram comparing the shapes of two unit wake structures provided by an embodiment of the present invention when μ=0.05 and the stable pitch speed q / Ω=0.012 during forward flight;

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

[0042] Figure 6 A schematic diagram of the composition structure of a device for quickly calculating rotor induced speed based on an improved vortex tube wake model provided in an embodiment of the present invention;

[0043] Figure 7 A schematic diagram of the composition structure of a device for quickly calculating rotor induced speed based on an improved vortex tube wake model provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings. The described embodiments should not be regarded as limiting the present invention. All other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.

[0045] In the following description, reference is made to "some embodiments", which describe a subset of all possible embodiments, but it is understood that "some embodiments" may be the same subset 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 present invention have the same meaning as those commonly understood by those skilled in the art to which the embodiments of the present invention pertain. The terms used in the embodiments of the present invention are only for the purpose of describing the embodiments of the present invention and are not intended to limit the present invention.

[0046] The following describes an exemplary application of a device for rapidly calculating rotor induced speed based on an improved vortex tube wake model according to an embodiment of the present invention. The device for rapidly calculating rotor induced speed based on an improved vortex tube wake model provided by an embodiment of the present invention can be implemented as a terminal or a server. In one implementation, the device for rapidly calculating rotor induced speed based on an improved vortex tube wake model provided by an embodiment of the present invention can be implemented as various types of terminals such as a laptop computer, a tablet computer, a desktop computer, and a mobile device; in another implementation, the device for rapidly calculating rotor induced speed based on an improved vortex tube wake model provided by an embodiment of the present invention can also be implemented as a server, wherein the server can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, content distribution networks (CDN, Content Delivery Network), and big data and artificial intelligence platforms. The terminal and the server can be directly or indirectly connected by wired or wireless communication, which is not limited in the embodiment of the present invention. Next, an exemplary application of the device for quickly calculating rotor induced speed based on the improved vortex tube wake model when it is implemented as a server will be described.

[0047] The embodiment of the present invention provides a method for quickly calculating the rotor induced speed based on an improved vortex tube wake model. Figure 1 , Figure 1 is a flow chart of a method for quickly calculating rotor induced speed based on an improved vortex tube wake model provided by an embodiment of the present invention, which is combined with Figure 1 The steps shown are explained.

[0048] Step S210 , obtaining a first coordinate conversion relationship between the local coordinate system of the in-tick-tick vortex unit and the local coordinate system of the vortex ring unit.

[0049] Here, the tic-tac-toe vortex unit is used to characterize the simplified wake structure unit, and the tic-tac-toe vortex unit 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 and simplify the wake structure or description method of the circular vortex ring unit. Each straight vortex segment is perpendicular to each other to form a tic-tac-toe vortex unit (such as Figure 2 For the convenience of description, this paper will refer to the simplified wake structure unit as a tic-tac-toe vortex unit.

[0051] In order to facilitate the description of the geometric shape of the wake structure and the fast calculation method of the induced velocity at a spatial point introduced in this paper, the local coordinate system O of the tic-tac-toe vortex is introduced first. VL X VL Y VL Z VL The local coordinate system O of the vortex ring VR X VR Y VR Z VR The coordinate transformation relationship between them. Figure 3 The local coordinate system O of the central vortex ring VR X VR Y VR Z VR and the local coordinate system O VL X VL Y VL Z VL The origin of is located at the center of the vortex ring, and the vortex ring and the well-shaped vortex are located in the same plane. When calculating the induced velocity of the space point P in the local vortex ring coordinate system, it is necessary to rotate the well-shaped vortex around the central axis of the vortex ring until the well-shaped 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 intersection lines of the planes coincide, and the angle of rotation can be represented by ψ. The coordinate transformation relationship can be expressed as:

[0052]

[0053] Step S220 , constructing a mapping relationship between the tic-tac-toe vortex unit and the vortex ring unit according to the high similarity characteristics of the Z-axis vertical induced velocities of the tic-tac-toe vortex unit and the vortex ring unit at the spatial point.

[0054] In some embodiments, the tic-tac-toe vortex unit is a simplified replacement for the vortex ring unit. The requirement is that when calculating the induced velocity of a specified spatial point, the induced velocity results calculated by the tic-tac-toe vortex unit and the vortex ring unit are infinitely close to achieve the effect of simulating the vortex ring unit. The tic-tac-toe vortex composed of infinitely long straight vortex segments and the vortex ring of unit radius have a high degree of similarity in the Z-axis vertical induced velocity distribution at the calculation node. Based on this property, the mapping relationship between the tic-tac-toe vortex unit and the vortex ring unit is constructed at the numerical level.

[0055] Step S230, when the length of the straight vortex section dominates the tic-tac-toe vortex induced velocity distribution characteristics, determining the mapping rule of the length of the straight vortex section according to the mapping relationship.

[0056] In some embodiments, the variable parameters of the straight vortex section are the length L of the straight vortex section and the circulation intensity Γ. In order to simplify the simplicity of the structural model calculation, the variable parameters of the tic-tac-toe vortex unit are set to four straight vortex sections using the same circulation intensity Γ and length L. As the height H increases, the length L of the straight vortex section will be used as a parameter to dominate the velocity distribution characteristics induced by the tic-tac-toe vortex. Figure 4 The mapping law of the straight vortex section length L as the height increases is shown.

[0057] In some embodiments, the mapping relationship curve can be fitted using a proxy model or other methods. In the present invention, the Dirichlet function in the δ function auxiliary function family is selected for fitting. As the height H of the calculation 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, calculating the vortex ring coordinates of the spatial point P on the vortex ring local coordinate system at the radial vector according to a second coordinate conversion relationship between the vortex ring local coordinate system and the disk plane coordinate system.

[0060] In some embodiments, the induced flow fields of the tic-tac-toe vortex unit and the vortex ring unit in the symmetry plane have good consistency. Although this is a local property, the local property can be extended to the entire space by means of the symmetry of the induced flow field of the equal-circular vortex ring unit space. The key point is that the tic-tac-toe vortex unit needs to be rotated around the axis of the vortex ring unit when calculating the induced velocity. W X W Y W Z W Quickly calculate the space point P(x p ,y p ,z p ) method is as follows:

[0061] In some embodiments, the coordinates of point P are converted from the rotor disc plane coordinate system O W XW Y W Z W Describes the transformation to the origin on the radius vector R VR The vortex ring local coordinate system O is the vector from the origin of the disk plane coordinate system to the center point of the vortex ring coordinate system VR X VR Y VR Z VR To describe it, it is necessary to move the origin of the coordinate system and rotate the coordinate system. The coordinates of the above space points in the local coordinate system of the vortex ring can be expressed as:

[0062]

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

[0064] In some embodiments, the method may further include calculating a rotation angle ψ between the vortex ring local coordinate system and the tic-tac-toe vortex local coordinate system:

[0065]

[0066] Among them, x VR is the distance of the spatial point P in the x-axis direction of the local parallel coordinate system of the vortex ring, y VR It is the distance of the spatial point P in the y-axis direction of the local parallel coordinate system of the vortex ring.

[0067] Step S250, calculating the tic-tac-toe vortex coordinates of the spatial point in the tic-tac-toe vortex local coordinate system based on the first coordinate transformation relationship and the vortex ring coordinates.

[0068] In some embodiments, the vortex is rotated around the central axis of the vortex ring until the coordinate system X of the vortex body is 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 intersection lines of the planes coincide with each other, and the coordinates P(x VL ,y VL ,z VL ), the tic-tac-toe vortex coordinates are expressed as:

[0069]

[0070] Step S260, calculating the tic-tac-toe vortex induced velocity of the spatial point according to the tic-tac-toe vortex coordinates.

[0071] In some embodiments, the induced velocity of the tic-tac-toe vortex unit is calculated according to the tic-tac-toe vortex coordinates.

[0072] Among them, T VR2VL It represents the coordinate transformation relationship between the local coordinate system of the vortex ring and the local coordinate system of the tic-tac-toe vortex.

[0073] Step S270, calculating the propeller disk induced velocity of the spatial point based on the mapping rule, the second coordinate transformation relationship and the tic-tac-toe vortex induced velocity.

[0074] In some embodiments, the induced velocity in the local coordinate system of the tic-tac-toe vortex is converted to the propeller disc plane coordinate system to obtain the propeller disc induced velocity:

[0075]

[0076] In some embodiments, the above step S210 may be determined in the following manner:

[0077] First, determine the local coordinate system O of the tic-tac-toe vortex VL X VL Y VL Z VL and the vortex ring local coordinate system O VR X VR Y VR Z VR The vortex ring unit and the vortex unit are located in the same plane. VL Y VL Z VL Medium X 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 to obtain a rotation angle. Finally, based on the rotation angle, the first coordinate transformation relationship is determined; the first coordinate transformation relationship:

[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 Positive below, X o Z o With Z W The angle between is the roll angle θ x , the left side of the vortex ring unit is positive, X oWith X W Z W The angle between the two is the yaw angle θ z , deflection to the left is positive.

[0082] The embodiment of the present invention provides a method for quickly calculating the rotor induced velocity based on the improved vortex tube wake model. Compared with numerical calculation models such as free wakes and viscous vortex particles, the method provided by the present invention has high calculation efficiency and can meet the needs of real-time simulation. Compared with the prior art, the present invention greatly improves the calculation efficiency of the induced inflow of the impeller disk after simplifying the description of the wake structure and applying a fast calculation method. When the vortex ring uses 1° azimuth angle division to superimpose the calculation of the induced velocity of the spatial point, it can not only shorten the calculation time by about 40 times, but also avoid a significant reduction in the calculation accuracy. In addition, compared with the dynamic inflow model, the present invention is not only slightly better in calculation accuracy, but also can calculate the induced velocity of any point in space, thereby assisting in the calculation of the aerodynamic interference between the rotor and other components, and has a high application value. At the same time, the calculation method is also applicable to various aircraft configurations, without the need to manually select model parameters, and has strong versatility.

[0083] The following describes an exemplary application of an embodiment of the present invention in a practical application scenario.

[0084] Vortex tube wake model (such as Figure 5 The vortex generated by the rotor forms a continuous tubular vortex tube that is dragged backward, forming the outer surface of the rotor wake. The vortex tube model is suitable for the analysis of various flight states. The calculation of the spatial induced velocity of the vortex tube wake structure generally uses a numerical method. The vortex tube is discretized into multiple vortex ring units perpendicular to the center line along the center line. The Biot-Savart law is used to calculate the spatial point induced velocity of each unit one by one and finally superimposed to obtain the calculation result. Further simplification of the vortex ring unit will effectively improve the solution speed of the vortex tube wake model or other wake models described by vortex ring units.

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

[0086] The present invention uses four straight vortex segments 1.1, 1.2, 1.3, and 1.4 that are tangent to the circular vortex ring to simulate and simplify the wake structure or description method based on the circular vortex ring unit. Each straight vortex segment is perpendicular to each other to form a "tic-tac-toe" vortex unit (such as Figure 2 As a description method of the wake structure, the tic-tac-toe vortex can replace the vortex ring unit 2 to describe the wake structure. The change in the size of the tic-tac-toe vortex will simulate the distortion of the vortex ring unit 2.

[0087] In the present invention, a simplified description method of the tail structure is proposed. T =0.005, μ=0.05, stable pitch speed during forward flight, q / Ω=0.012, comparison of the wake geometry of the vortex tube wake model described by the vortex ring unit and the "tic-tac-toe vortex" unit.

[0088] In order to reflect the computational efficiency of the fast calculation method of the rotor induced speed based on the improved vortex tube wake model proposed in the present invention, the following will be calculated and compared with a new simplified description method and fast calculation method of the wake structure proposed in the present invention and a circular vortex tube wake structure description and conventional calculation method under the classic vortex tube wake with the wake inclination angle χ of 0°, 30°, 45°, and 60°, wherein the wake inclination angle has the following calculation formula:

[0089] χ=arctan(μ / λ) (9),

[0090] In some embodiments, the method for calculating the induced velocity of the circular vortex ring unit in space is to use 360 ​​straight vortex segments to discretely divide the circular vortex ring unit into polygonal units with a discrete step length of 1° azimuth, and then use the Biot-Savart law to calculate the induced velocity of the midpoint in space for each straight vortex segment, and superimpose the calculation results of all straight vortex segments to obtain the final induced velocity result.

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

[0092]

[0093] in, is the dimensionless radius of the blade, and ψ represents the azimuth angle. Table 1 gives the relative errors of different description methods and calculation methods under different wake inclination angles:

[0094] Table 1 Comparison of inflow coefficient identification results in stable flight state

[0095]

[0096]

[0097] Table 1 Comparison of identification results of inflow coefficients in stable flight state

[0098]

[0099] Table 2 Comparison of propeller disk inflow calculation time in stable flight state

[0100]

[0101] It can be seen from the identification results of the inflow coefficient that the relative deviation of the identification results of the propeller disc induced inflow of the vortex ring unit and the tic-tac-toe vortex unit in the stable flight state is small, not exceeding 5% in the test, and the calculation results have good consistency. However, the calculation time on a personal notebook equipped with a CPU model of AMD Ryzen 7 4800-H shows that the new simplified description method and fast calculation method of the wake structure proposed in the present invention is about 40 times shorter in calculation time than the vortex tube model described by the vortex ring, which fully meets the real-time simulation calculation efficiency requirements required in engineering, has high calculation efficiency, and has important application value.

[0102] The embodiment of the present invention provides a method for quickly calculating the rotor induced velocity based on the improved vortex tube wake model. Compared with numerical calculation models such as free wakes and viscous vortex particles, the method provided by the present invention has high calculation efficiency and can meet the needs of real-time simulation. Compared with the prior art, the present invention greatly improves the calculation efficiency of the induced inflow of the impeller disk after simplifying the description of the wake structure and applying a fast calculation method. When the vortex ring uses 1° azimuth angle division to superimpose the calculation of the induced velocity of the spatial point, it can not only shorten the calculation time by about 40 times, but also avoid a significant reduction in the calculation accuracy. In addition, compared with the dynamic inflow model, the present invention is not only slightly better in calculation accuracy, but also can calculate the induced velocity of any point in space, thereby assisting in the calculation of the aerodynamic interference between the rotor and other components, and has a high application value. At the same time, the calculation method is also applicable to various aircraft configurations, without the need to manually select model parameters, and has strong versatility.

[0103] Figure 6 FIG. 1 is a schematic diagram of the structure of a device for quickly calculating rotor induced speed based on an improved vortex tube wake model provided by an embodiment of the present invention. Figure 6As shown, a fast calculation device 600 for rotor induced velocity based on an improved vortex tube wake model includes: an acquisition module 601, used to obtain a first coordinate transformation relationship between the tic-tac-toe vortex local coordinate system of the tic-tac-toe vortex unit and the vortex ring local coordinate system of the vortex ring unit; the tic-tac-toe vortex unit is used to characterize a simplified wake structure unit, and the tic-tac-toe vortex unit includes four straight vortex segments tangent to the vortex ring unit; a construction module 602, used to construct a mapping relationship between the tic-tac-toe vortex unit and the vortex ring unit according to the high similarity characteristics of the Z-axis vertical induced velocity of the tic-tac-toe vortex unit and the vortex ring unit at a spatial point; a determination module 603, used to determine the mapping relationship between the tic-tac-toe vortex unit and the vortex ring unit according to ... The induced velocity distribution characteristics of the straight vortex segment length dominate the A mapping relationship is used to determine the mapping law of the length of the straight vortex section; a calculation module 604 is used to calculate the vortex ring coordinates of the spatial point P in the local coordinate system of the vortex ring at the radial vector according to the second coordinate transformation relationship between the local coordinate system of the vortex ring and the impeller disk plane coordinate system; the calculation module 604 is also used to calculate the tic-tac-toe vortex coordinates of the spatial point in the local coordinate system of the tic-tac-toe vortex based on the first coordinate transformation relationship and the vortex ring coordinates; the calculation module 604 is also used to calculate the tic-tac-toe vortex induced velocity of the spatial point according to the tic-tac-toe vortex coordinates; the calculation module 604 is also used to calculate the impeller disk induced velocity of the spatial point based on the mapping law, the second coordinate transformation relationship and the tic-tac-toe vortex induced velocity.

[0104] In some embodiments, the calculation module 604 is further used to calculate the rotation angle between the local coordinate system of the tic-tac-toe vortex and the local coordinate system of the vortex ring based on the vortex ring coordinates; the rotation angle ψ is expressed as:

[0105]

[0106] Among them, x VR is the distance of the spatial point P in the x-axis direction of the local parallel coordinate system of the vortex ring, y VR It is the distance of the spatial point P in the y-axis direction of the local parallel coordinate system of the vortex ring.

[0107] In some embodiments, the acquisition module 601 is further used to determine the local coordinate system of the tic-tac-toe vortex. VL X VL Y VL Z VL and the vortex ring local coordinate system O VR X VR Y VR Z VR Located at the center of the vortex ring unit; the vortex ring unit and the well-shaped vortex unit are located in the same plane; the well-shaped vortex is rotated by the central axis of the vortex ring to change the well-shaped vortex body coordinate system X VL Y VL ZVL Medium X 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 to obtain a rotation angle; based on the rotation angle, the first coordinate transformation relationship is determined; the first coordinate transformation relationship is:

[0108]

[0109] In some embodiments, the second coordinate transformation relationship is expressed as:

[0110]

[0111] Among them, X o With X W Y W The angle between them is the pitch angle θ y , X o Positive below, X o Z o With Z W The angle between is the roll angle θ x , the left side of the vortex ring unit is positive, X o With X W Z W The angle between the two is the yaw angle θ z , deflection to the left is positive.

[0112] In some embodiments, the propeller disc plane coordinate system X W Y W Z W The local coordinate system X of the vortex ring o Y o Z o The propeller disc induced velocity is calculated by:

[0113]

[0114] in, represents the transposition of the coordinate transformation relationship between the vortex ring local coordinate system and the disk plane coordinate system, Indicates a mapping relationship.

[0115] It should be noted that the description of the device of the embodiment of the present invention is similar to the description of the above method embodiment, and has similar beneficial effects as the method embodiment, so it is not repeated. For technical details not disclosed in the device embodiment, please refer to the description of the method embodiment of the present invention for understanding.

[0116] It should be noted that, in the embodiment of the present invention, if the above-mentioned method for rapid calculation of rotor induced speed based on the improved vortex tube wake model is implemented in the form of a software function 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 embodiment of the present invention can be essentially or partly reflected in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a terminal to execute all or part of the methods described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), disk or optical disk and other media that can store program codes. In this way, the embodiment of the present invention is not limited to any specific combination of hardware and software.

[0117] Correspondingly, an embodiment of the present invention provides a device for quickly calculating rotor induced speed based on an improved vortex tube wake model. Figure 7 is a schematic diagram of the composition structure of a device for quickly calculating rotor induced speed based on an improved vortex tube wake model provided by an embodiment of the present invention, such as Figure 7 As shown, the device 700 for quickly calculating rotor induced speed based on the improved vortex tube 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 device 700 for quickly calculating rotor induced speed based on the improved vortex tube 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 each module in the processor 701 and the device 700 for quickly calculating rotor induced speed based on the improved vortex tube wake model, which can be implemented by flash memory (FLASH) or random access memory (Random Access Memory, RAM).

[0118] An embodiment of the present invention provides a storage medium storing executable instructions, wherein the executable instructions are stored. When the executable instructions are executed by a processor, the processor will be caused to execute the method provided by the embodiment of the present invention, for example, Figure 1 The method shown.

[0119] In some embodiments, the storage medium can be a computer-readable storage medium, for example, a ferroelectric 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), a flash memory, a magnetic surface memory, an optical disk, or a compact disk read-only memory (CD-ROM), etc.; it can also be various devices including one or any combination of the above memories.

[0120] In some embodiments, executable instructions may be in 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 stand-alone program or as a module, component, subroutine or other unit suitable for use in a computing environment.

[0121] As an example, executable instructions may, but need not necessarily, correspond to a file in a file system, may be stored as part of a file storing other programs or data, for example, in one or more scripts in a Hyper Text Markup Language (HTML) document, in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files storing one or more modules, subroutines, or code portions). As an example, executable instructions may be deployed to be executed on one electronic device, or on multiple electronic devices located at one location, or on multiple electronic devices distributed at multiple locations and interconnected by a communication network.

[0122] The above description is only an embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement and improvement made within the spirit and scope of the present invention are included in the protection scope of the present invention.

[0123] It should be understood that "one embodiment" or "an embodiment" mentioned throughout the specification means that specific features, structures or characteristics related to the embodiment are included in at least one embodiment of the present invention. Therefore, "in one embodiment" or "in an embodiment" appearing throughout the specification does not necessarily refer to the same embodiment. In addition, these specific features, structures or characteristics can be combined in one or more embodiments in any suitable manner. It should be understood that in various embodiments of the present invention, the size of the serial number of the above-mentioned processes does not mean the 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 embodiment of the present invention. The serial numbers of the above-mentioned embodiments of the present invention are only for description and do not represent the advantages and disadvantages of the embodiments.

[0124] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method or device. In the absence of further restrictions, an element defined by the statement "comprises one..." does not exclude the presence of other identical elements in the process, method, article or device including the element. In several embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as: multiple units or components can be combined, or can be integrated into another system, or some features can be ignored, or not executed.

[0125] The above is only an embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for quickly calculating rotor induced speed based on an improved vortex tube wake model, characterized in that: The method comprises: Obtaining a first coordinate conversion relationship between a local coordinate system of a tic-tac-toe vortex of a tic-tac-toe vortex unit and a local coordinate system of a vortex ring of a vortex ring unit; the tic-tac-toe vortex unit is used to characterize a simplified wake structure unit, and the tic-tac-toe vortex unit includes four straight vortex segments tangent to the vortex ring unit; According to the high similarity characteristics of the Z-axis vertical induced velocity of the tic-tac-toe vortex unit and the vortex ring unit at the spatial point, a mapping relationship between the tic-tac-toe vortex unit and the vortex ring unit is constructed; In the case where the length of the straight vortex section dominates the tic-tac-toe vortex induced velocity distribution characteristics, the mapping law of the length of the straight vortex section is determined according to the mapping relationship; Calculating the vortex ring coordinates of the spatial point P on the vortex ring local coordinate system at the radial vector according to a second coordinate transformation relationship between the vortex ring local coordinate system and the disk plane coordinate system; Based on the first coordinate transformation relationship and the vortex ring coordinates, calculating the tic-tac-toe vortex coordinates of the spatial point in the tic-tac-toe vortex local coordinate system; Calculating the tic-tac-toe vortex induced velocity of the spatial point according to the tic-tac-toe vortex coordinates; Based on the mapping rule, the second coordinate transformation relationship and the tic-tac-toe vortex induced velocity, the impeller disk induced velocity of the spatial point is calculated.

2. The method according to claim 1, characterized in that The method further comprises: Based on the vortex ring coordinates, the rotation angle between the local coordinate system of the tic-tac-toe vortex and the local coordinate system of the vortex ring is calculated; the rotation angle ψ is expressed as: Among them, x VR is the distance of the spatial point P in the x-axis direction of the local parallel coordinate system of the vortex ring, y VR It is the distance of the spatial point P in the y-axis direction of the local parallel coordinate system of the vortex ring.

3. The method according to claim 2, characterized in that The obtaining of a first coordinate conversion relationship between the local coordinate system of the tic-tac-toe vortex of the tic-tac-toe vortex unit and the local coordinate system of the vortex ring of the vortex ring unit includes: Determine the local coordinate system O of the tic-tac-toe vortex VL X VL Y VL Z VL and the vortex ring local coordinate system O VR X VR Y VR Z VR Located at the center of the vortex ring unit; the vortex ring unit and the tic-tac-toe vortex unit are located in the same plane; The vortex body coordinate system X is rotated by rotating the vortex ring through the central axis of the vortex ring. VL Y VL Z VL Medium X 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, and the rotation angle is obtained; Based on the rotation angle, the first coordinate transformation relationship is determined; the first coordinate transformation relationship:

4. The method according to claim 1, characterized in that: The second coordinate transformation relationship is expressed as: Among them, X o With X W Y W The angle between them is the pitch angle θ y , X o Positive below, X o Z o With Z W The angle between is the roll angle θ x , the left side of the vortex ring unit is positive, X o With X W Z W The angle between the two is the yaw angle θ z , deflection to the left is positive.

5. The method according to claim 1, characterized in that The propeller disc plane coordinate system X W Y W Z W The local coordinate system X of the vortex ring o Y o Z o The propeller disc induced velocity is calculated by: in, represents the transposition of the coordinate transformation relationship between the vortex ring local coordinate system and the disk plane coordinate system, Indicates a mapping relationship.

6. A device for quickly calculating rotor induced speed based on an improved vortex tube wake model, characterized in that: The device comprises: An acquisition module is used to obtain a first coordinate conversion relationship between a local coordinate system of a tic-tac-toe vortex of a tic-tac-toe vortex unit and a local coordinate system of a vortex ring of a vortex ring unit; the tic-tac-toe vortex unit is used to characterize a simplified wake structure unit, and the tic-tac-toe vortex unit includes four straight vortex segments tangent to the vortex ring unit; A construction module, for constructing a mapping relationship between the tic-tac-toe vortex unit and the vortex ring unit according to the high similarity characteristics of the Z-axis vertical induced velocities of the tic-tac-toe vortex unit and the vortex ring unit at a spatial point; A determination module, for determining the mapping rule of the straight vortex section length according to the mapping relationship when the straight vortex section length is the dominant factor in the tic-tac-toe vortex induced velocity distribution characteristic; A calculation module, used for calculating the vortex ring coordinates of the spatial point P on the vortex ring local coordinate system at the radial vector according to a second coordinate transformation relationship between the vortex ring local coordinate system and the disk plane coordinate system; The calculation module is further used to calculate the tic-tac-toe vortex coordinates of the spatial point in the tic-tac-toe vortex local coordinate system based on the first coordinate transformation relationship and the vortex ring coordinates; The calculation module is further used to calculate the tic-tac-toe vortex induced velocity of the spatial point according to the tic-tac-toe vortex coordinates; The calculation module is further used to calculate the propeller disk induced velocity of the spatial point based on the mapping rule, the second coordinate transformation relationship and the tic-tac-toe vortex induced velocity.

7. A device for quickly calculating rotor induced speed based on an improved vortex tube wake model, characterized in that: include: A memory for storing executable instructions; The processor is used to implement the method for quickly calculating the rotor induced speed based on the improved vortex tube wake model as described in any one of claims 1 to 5 when executing the executable instructions stored in the memory.

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

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