Water droplet collision coefficient determination method, apparatus and terminal for icing of wind turbine blades, and medium

Abstract

A water droplet collision coefficient determination method for icing of wind turbine blades. The method comprises: calculating influence coefficients and disturbance potential data of wind turbine blade boundaries on the basis of a coordinate set of the wind turbine blade boundaries in combination with a boundary element algorithm; calculating an airflow speed of a boundary outfield area point; on the basis of an initialized water droplet and the airflow speed and by means of a Lagrange algorithm, determining the stress state of the water droplet; tracking a motion trajectory of the water droplet, and when the water droplet collides with the surface of a wind turbine blade, determining the collision position and collision speed of the water droplet; and obtaining a local collision coefficient of the collision position of the water droplet on the basis of the collision speed, a normal vector of the collision position, and the airflow speed.

Description

Method, device, terminal and medium for determining collision coefficient of ice droplets on wind turbine blades

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on July 21, 2023, with application number 202310906033.1 and invention name “Method, device, terminal and medium for determining the collision coefficient of ice droplets on wind turbine blades”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the technical field of wind power generation simulation, and in particular to a method, device, terminal and medium for determining the collision coefficient of ice droplets on wind turbine blades. Background Art

[0003] As a clean, renewable energy source, wind energy is gradually being accepted and widely used in more and more countries. As wind power technology matures, many developed countries have increased their investment in the wind energy industry, and my country's wind power industry is also growing rapidly.

[0004] In recent years, the wind power industry in Sichuan, Chongqing, Yunnan and other regions of my country has also been increasing year by year. These regions are located in the southwest of my country, with a humid climate, prominent plateau and mountainous terrain features, and winter temperatures around 0℃, which provides environmental conditions for icing. The problem of icing on wind turbine blades has gradually become prominent, and the annual average power generation loss caused by icing on wind turbine blades can be as high as 30%; secondly, icing on wind turbine blades can change the structure of wind turbines, making wind turbine technical components brittle and reducing the service life of wind turbines. Furthermore, when the temperature rises, the ice on wind turbine blades falls off and is thrown out under the action of centrifugal force, seriously endangering the personal safety of wind farm workers.

[0005] Wind turbines operate under special conditions, and the monitoring and early warning mechanism for blade icing is imperfect. Simulating its growth form and rate based on environmental conditions is an important method. Currently, the most widely used method is to use CFD fluid mechanics simulation software to simulate the flow field analysis, water droplet collision and freezing involved in wind turbine icing. The calculation process of this method is relatively complicated, and the wind turbine is large in size, has a large number of grids, and has low calculation efficiency. To a certain extent, this restricts the application of this technology to icing prediction and early warning in wind turbine projects.

[0006] Summary of the Invention

[0007] The present application provides a method, device, terminal and medium for determining the collision coefficient of ice droplets on wind turbine blades, which are used to solve the technical problem of low computational efficiency of existing wind turbine blade ice simulation technology.

[0008] To solve the above technical problems, the first aspect of the present application provides a method for determining the collision coefficient of ice droplets on wind turbine blades, comprising:

[0009] Calculate the influence coefficient and disturbance potential data of the fan blade boundary according to the coordinate set of the fan blade boundary in combination with the boundary element algorithm;

[0010] Calculating the airflow velocity at a point in the boundary outer field region according to the influence coefficient and the disturbance potential data;

[0011] Determining the force state of the water droplet by using a Lagrangian algorithm based on the initialized water droplet and the airflow velocity;

[0012] tracking the motion trajectory of the water droplet according to the force state of the water droplet, and determining the collision position and collision speed of the water droplet when the water droplet collides with the surface of the fan blade;

[0013] The local collision coefficient of the water droplet collision position is obtained according to the collision speed, the normal vector of the collision position and the airflow speed in combination with a calculation formula for the local collision coefficient of the water droplet.

[0014] Preferably, the water droplet local collision coefficient calculation formula is specifically:

[0015] Where, β1 P is the local collision coefficient of the water droplet P, V x is the x-axis component of the collision velocity, V y is the y-axis component of the collision velocity, U is the airflow velocity, n jx is the x-axis component of the normal vector of the blade surface that the water droplet hits, n jy is the y-axis component of the normal vector of the blade surface that the water droplet hits.

[0016] Preferably, calculating the airflow velocity at a point in the boundary outer field region according to the influence coefficient and the disturbance potential data specifically includes:

[0017] Calculating the flow field disturbance potential data of the flow field region outside the boundary according to the influence coefficient and the disturbance potential data and combining the parameter relationship between the influence coefficient and the disturbance potential data;

[0018] According to the parameter relationship between the flow field disturbance potential data and the airflow velocity, the airflow velocity at the point in the boundary outer field area is calculated.

[0019] Preferably, before calculating the influence coefficient of the fan blade boundary and the disturbance potential data by combining the boundary element algorithm, the method further includes:

[0020] According to the coordinate set of the boundary of the wind blade, the coordinate points of the boundary of the wind blade are interpolated by a linear interpolation method to obtain the coordinate set of the boundary of the wind blade after interpolation.

[0021] Preferably, tracking the motion trajectory of the water droplet according to the force state of the water droplet, and determining the collision position and collision speed of the water droplet when the water droplet collides with the surface of the fan blade specifically includes:

[0022] Calculate the real-time position of the water drop after the time step according to the initial position, initial velocity and force state of the water drop and a preset time step;

[0023] According to the position of the water droplet, the collision state of the water droplet and the surface of the fan blade is determined by the vector judgment method. When the water droplet collides with the surface of the fan blade, the collision position and collision speed of the water droplet are determined. If no collision occurs, based on the current position, the preset time step is continued to be combined to calculate the real-time position of the water droplet after the time step.

[0024] Preferably, the process of tracking the motion trajectory of the water droplet further includes:

[0025] According to the motion trajectory of the water droplet and in combination with a preset motion trajectory smoothness value, when the smoothness of the motion trajectory is lower than the condition of the motion trajectory smoothness value, the time step is reduced until the smoothness of the motion trajectory is not lower than the motion trajectory smoothness value.

[0026] Preferably, the process of tracking the motion trajectory of the water droplet further includes:

[0027] According to the distance between the current position of the water droplet and the surface of the wind turbine blade, when the distance is greater than a preset distance threshold and the smoothness of the motion trajectory is not less than the motion trajectory smoothness value, the time step is increased.

[0028] At the same time, the second aspect of the present application provides a device for determining the collision coefficient of ice droplets on wind turbine blades, comprising:

[0029] A boundary metadata calculation unit, configured to calculate the influence coefficient and disturbance potential data of the wind blade boundary according to a coordinate set of the wind blade boundary in combination with a boundary element algorithm;

[0030] A flow field airflow velocity calculation unit, configured to calculate the airflow velocity at a point in the boundary outer field area according to the influence coefficient and the disturbance potential data;

[0031] a water drop force analysis unit, configured to determine the force state of the water drop by using a Lagrangian algorithm based on the initialized water drop and the airflow velocity;

[0032] a motion trajectory tracking unit, configured to track the motion trajectory of the water droplet according to the force state of the water droplet, and determine the collision position and collision speed of the water droplet when the water droplet collides with the surface of the fan blade;

[0033] The local collision coefficient calculation unit is used to obtain the local collision coefficient of the water droplet collision position according to the collision speed, the normal vector of the collision position and the airflow speed in combination with the water droplet local collision coefficient calculation formula.

[0034] A third aspect of the present application provides a terminal for determining a collision coefficient of ice droplets on wind turbine blades, comprising: a memory and a processor;

[0035] The memory stores a computer program that can be executed on the processor;

[0036] When the processor executes the computer program, the method for determining the collision coefficient of ice droplets on wind turbine blades provided in the first aspect of the present application is implemented.

[0037] The fourth aspect of the present application provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are executed by a control processor, the method for determining the collision coefficient of ice droplets on wind turbine blades provided in the first aspect of the present application is implemented.

[0038] It can be seen from the above technical solutions that this application has the following advantages:

[0039] The solution provided in the present application obtains the airflow velocity at the boundary outer field point through the boundary element method, combines the Lagrangian algorithm to track and calculate the force state and motion trajectory of the water droplet, and then judges the collision situation of the water droplet. When the water droplet collides with the surface of the wind turbine blade, the coordinates of the water droplet collision point and the collision velocity are quickly calculated based on the force state and motion trajectory of the water droplet. Finally, according to the collision velocity, the normal vector of the collision position and the airflow velocity, combined with the calculation formula of the water droplet local collision coefficient, the necessary data for analyzing the icing of the wind turbine generator - the local collision coefficient can be obtained. There is no need to establish a complex flow field grid model, the calculation efficiency is higher, and the technical problem of low calculation efficiency of the existing wind turbine blade icing simulation technology can be solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0041] FIG1 is a flow chart of an embodiment of a method for determining the collision coefficient of ice droplets on wind turbine blades provided by the present application;

[0042] FIG2 is a flow chart of another embodiment of a method for determining the collision coefficient of ice droplets on wind turbine blades provided by the present application;

[0043] FIG3 is a schematic diagram of the calculation of the trajectory tracking of water droplets on the outside of a wind blade in a method for determining the collision coefficient of ice droplets on a wind blade provided by this application;

[0044] FIG4 is a schematic diagram of a water droplet collision vector on a wind blade surface in a method for determining a collision coefficient of ice droplets on a wind blade provided by this application;

[0045] FIG5 is a comparison diagram of the local water droplet collision coefficient on the surface of a wind blade provided by a method for determining the ice droplet collision coefficient of a wind blade provided by the present application and a traditional CFD method;

[0046] FIG6 is a schematic diagram of the trajectory of water droplets on the outside of a wind blade at different time steps in a method for determining the collision coefficient of ice droplets on wind blades provided by this application;

[0047] FIG7 is a schematic structural diagram of an embodiment of a device for determining the collision coefficient of ice droplets on wind turbine blades provided by the present application;

[0048] FIG8 is a schematic structural diagram of an embodiment of a terminal for determining the collision coefficient of ice droplets on wind turbine blades provided in the present application. DETAILED DESCRIPTION

[0049] The embodiments of the present application provide a method, device, terminal and medium for determining the collision coefficient of ice droplets on wind turbine blades, which are used to solve the technical problem of low computational efficiency of existing wind turbine blade ice simulation technology.

[0050] In order to make the purpose, features, and advantages of the invention of this application more obvious and easy to understand, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the embodiments described below are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0051] First, a detailed description of a basic embodiment of a method for determining the collision coefficient of ice droplets on wind turbine blades provided by this application is as follows:

[0052] Referring to FIG1 , a method for determining the collision coefficient of ice droplets on wind turbine blades provided in the first embodiment of the present application includes:

[0053] Step 101: Calculate the influence coefficient and disturbance potential data of the fan blade boundary based on the coordinate set of the fan blade boundary and the boundary element algorithm;

[0054] Step 102: Calculate the airflow velocity at the boundary outer field area point based on the influence coefficient and the disturbance potential data;

[0055] Step 103: Based on the initialized water droplet and airflow velocity, determine the force state of the water droplet using the Lagrangian algorithm;

[0056] Step 104: Track the motion trajectory of the water droplet according to the force state of the water droplet, and determine the collision position and collision speed of the water droplet when the water droplet collides with the surface of the fan blade;

[0057] Step 105 : According to the collision velocity, the normal vector at the collision position, and the airflow velocity, the local collision coefficient of the water droplet is obtained in combination with a calculation formula for the local collision coefficient of the water droplet.

[0058] It should be noted that, first, according to the fan blade structure to be simulated, a two-dimensional point coordinate set A of the fan blade boundary Γ is obtained, and then based on the two-dimensional point coordinate set A, the influence coefficients G, H and disturbance potential data corresponding to the fan blade boundary Γ are solved. The disturbance potential data mentioned in this application generally include: disturbance velocity potential and the perturbation velocity potential The derivative Q along the blade normal is used, and then the airflow velocity at the point outside the boundary field is calculated based on the influence coefficient and the disturbance potential data. The solution method for the influence coefficients G and H can refer to the conventional boundary element theory. The disturbance potential data can be solved based on the influence coefficient, combined with the relationship between the influence coefficient and the potential function and its derivative along the blade normal. The relationship between the influence coefficient and the potential function and its derivative along the blade normal is shown in the following formula:

[0059] Next, initialize the water drop object. The initialized parameters include but are not limited to: initial position coordinates and initial velocity. Based on the airflow velocity in the external flow field area obtained in the above steps, combined with the Lagrangian algorithm, perform force analysis on the water drop, solve the force of the airflow on the water drop, and calculate the motion trajectory and velocity of the water drop under the force. When the water drop collides with the surface of the fan blade, determine the collision position and collision velocity of the water drop. When the collision point position and collision point velocity are known, the local collision coefficient of the water drop collision position can be obtained based on the collision velocity, the normal vector of the collision position and the airflow velocity obtained in the previous steps, combined with the water drop local collision coefficient calculation formula.

[0060] The method for determining the collision coefficient of ice droplets on wind turbine blades provided in this embodiment obtains the airflow velocity at the points in the boundary field area through the boundary element method, and combines the Lagrangian algorithm to track and calculate the force state and motion trajectory of the water droplets, and then judges the collision situation of the water droplets. When the water droplets collide with the surface of the wind turbine blade, the coordinates of the water droplet collision point and the collision velocity are quickly calculated based on the force state and motion trajectory of the water droplets. Finally, according to the collision velocity, the normal vector of the collision position and the airflow velocity, combined with the calculation formula of the local collision coefficient of the water droplets, the necessary data for analyzing the icing of the wind turbine generator - the local collision coefficient can be obtained. Since the collision coefficient determination process of the present application avoids the grid division and finite element calculation steps, there is no need to construct a complex flow field grid model, thereby improving the calculation efficiency.

[0061] The above is a detailed description of a basic embodiment of a method for determining the collision coefficient of ice droplets on wind blades provided by this application. The following is a detailed description of a further embodiment of a method for determining the collision coefficient of ice droplets on wind blades provided by this application based on the above basic embodiment.

[0062] Referring to FIG. 2 , the second embodiment of the present application provides a method for determining the collision coefficient of ice droplets on wind turbine blades based on the previous embodiment, as follows:

[0063] Furthermore, before calculating the influence coefficient of the fan blade boundary and the disturbance potential data by combining the boundary element algorithm in step 101, the following steps may be further included:

[0064] Step 1001: interpolate the coordinate points of the fan blade boundary using a linear interpolation method according to the coordinate set of the fan blade boundary to obtain the interpolated coordinate set of the fan blade boundary.

[0065] It should be noted that the solution provided in this embodiment can also be based on the two-dimensional point coordinate set A of the wind blade boundary Γ, and can also use the set A to perform linear interpolation to obtain a boundary point coordinate set B with denser coordinates, so that the processed coordinate set B can replace the original set A to perform subsequent steps, further improving the calculation accuracy.

[0066] Furthermore, the step 102 mentioned in calculating the airflow velocity at the boundary outer field area point according to the influence coefficient and the disturbance potential data specifically includes the following steps:

[0067] Step 1021: Calculate the flow field disturbance potential data of the flow field region outside the boundary according to the influence coefficient and the disturbance potential data, combined with the parameter relationship between the influence coefficient and the disturbance potential data;

[0068] Step 1022: Calculate the airflow velocity at the boundary outer field area point based on the parameter relationship between the flow field disturbance potential data and the airflow velocity.

[0069] It should be noted that the perturbation potential flow value on the known boundary Then, we can know that the disturbance potential flow value of any point in the flow field outside the boundary is:

[0070] Using the potential function φ and air velocity u(u x ,u y ) to solve the airflow velocity at any point in the external flow field; the potential function φ and the disturbance potential flow and air flow velocity u(u x ,u y ) is shown in the following formula:

[0071] in is the potential function value at an infinite distance away from the boundary of the wind turbine blade, specifically:

[0072] Furthermore, in step 104, the motion trajectory of the water droplet is tracked according to the force state of the water droplet, and when the water droplet collides with the surface of the wind turbine blade, the collision position and collision speed of the water droplet are determined. The steps may specifically include:

[0073] Step 1041: Calculate the real-time position of the water drop after the time step according to the initial position, initial velocity, and force state of the water drop and a preset time step;

[0074] Step 1042: Based on the position of the water droplet, the collision state of the water droplet and the surface of the fan blade is determined by the vector judgment method. When the water droplet collides with the surface of the fan blade, the collision position and collision speed of the water droplet are determined. If no collision occurs, based on the current position, the preset time step is continued to be combined to calculate the real-time position of the water droplet after the time step.

[0075] It should be noted that based on the force analysis of the water droplet, the drag force of the airflow on the water droplet and the water droplet velocity are solved, as shown in Figure 3, and the position reached by the water droplet after time dt is calculated; the viscous resistance (airflow drag) of the water droplet can be expressed as:

[0076] Where mw is the mass of the water droplet (kg); Sw is the maximum cross-sectional area of ​​the water droplet, m2; u and v are the two-dimensional velocity vectors of the airflow and water droplet, respectively (m / s); ρa is the air density (kg / m3).

[0077] Track and calculate the trajectory of water droplets. Reduce the time step dt when the water droplets approach the fan blades. Use the vector judgment method to determine whether the water droplet movement collides with the blade surface. When the water droplet collides with the surface of the fan blade, determine the collision position and collision speed of the water droplet. If no collision occurs, based on the current position, continue to combine the preset time step to calculate the real-time position of the water droplet after the time step.

[0078] To determine the collision position and collision speed of the water droplet, as shown in Figure 4, the distance that the water droplet P moves forward for each time step is solved. i ,y i ) point is the nearest line unit O(x j ,y j ), the normal vector of line element O is n j (n jx ,n jy ), then the state of water droplet P colliding with the fan blade is:

[0079] When the coordinates and velocity of the collision point are known, the algorithm proposed in this invention is used to calculate the distribution of the local collision coefficient β1 of the water droplet; assuming that the air flow velocity is U and the collision velocity of the water droplet P on the line unit O of the fan blade is V p (V x ,V y ), then the local water droplet collision coefficient value at this position can be obtained according to the following formula:

[0080] As shown in FIG5 , by comparing the calculated values ​​of the local water drop coefficient calculated by traditional CFD, it can be found that the results obtained by the present invention are more accurate and the error is within an acceptable range. However, the method of the present invention avoids the meshing and finite element calculation steps, thereby improving the calculation efficiency.

[0081] Furthermore, the process of tracking the motion trajectory of the water droplets also includes:

[0082] According to the motion trajectory of the water droplet and the preset motion trajectory smoothness value, when the smoothness of the motion trajectory is lower than the motion trajectory smoothness value condition, the time step is reduced until the smoothness of the motion trajectory is not lower than the motion trajectory smoothness value.

[0083] Furthermore, the process of tracking the motion trajectory of the water droplets also includes:

[0084] According to the distance between the current position of the water droplet and the surface of the wind turbine blade, when the distance is greater than a preset distance threshold and the smoothness of the motion trajectory is not less than the motion trajectory smoothness value, the time step is increased.

[0085] It should be noted that, in order to further improve the calculation effect, the dynamic control strategy adopted by the time step dt mentioned in this embodiment can be adjusted according to the smoothness of the water droplet motion trajectory. If the water droplet motion trajectory curve is distorted, it means that the value of the time step dt is too large and the time step needs to be reduced. As shown in Figure 6, when the time step dt is adjusted from 1 to 1 / 32, the water droplet trajectory gradually becomes smooth. In addition, if the smoothness is good and the water droplet is far away from the fan blade, the time step can be appropriately increased to shorten the calculation time.

[0086] The above is a detailed description of a further embodiment of a method for determining the collision coefficient of ice droplets on wind turbine blades provided by the present application. The following is a detailed description of an embodiment of a device for determining the collision coefficient of ice droplets on wind turbine blades provided by the present application, specifically as follows:

[0087] Referring to FIG. 7 , this embodiment provides a device for determining the collision coefficient of ice droplets on wind turbine blades, comprising:

[0088] The boundary metadata calculation unit 201 is used to calculate the influence coefficient and disturbance potential data of the wind blade boundary according to the coordinate set of the wind blade boundary in combination with the boundary element algorithm;

[0089] The flow field airflow velocity calculation unit 202 is used to calculate the airflow velocity of the boundary outer field area point according to the influence coefficient and the disturbance potential data;

[0090] The water drop force analysis unit 203 is used to determine the force state of the water drop by using the Lagrangian algorithm based on the initialized water drop and air flow velocity;

[0091] The motion trajectory tracking unit 204 is used to track the motion trajectory of the water droplet according to the force state of the water droplet, and determine the collision position and collision speed of the water droplet when the water droplet collides with the surface of the wind turbine blade;

[0092] The local collision coefficient calculation unit 205 is used to obtain the local collision coefficient of the water droplet collision position according to the collision speed, the normal vector of the collision position and the airflow speed, combined with the water droplet local collision coefficient calculation formula.

[0093] The above is a detailed description of an embodiment of a wind turbine blade icing morphology simulation device provided by the present application. The following is a detailed description of an embodiment of a wind turbine blade icing morphology simulation terminal and a computer-readable storage medium provided by the present application.

[0094] Referring to FIG8 , a fourth embodiment of the present application provides an embodiment of a wind turbine blade ice morphology simulation terminal. Terminal types include, but are not limited to, personal computers, industrial computers, servers, and embedded intelligent devices. The wind turbine blade ice morphology simulation terminal provided in this embodiment includes: a memory 33 and a processor 31 , and the memory and processor may be connected via a bus 34 .

[0095] The memory 33 stores a computer program that can be run on the processor 31;

[0096] When the processor 31 executes the computer program, the method for determining the collision coefficient of ice droplets on wind turbine blades provided in the first embodiment or the second embodiment of the present application is implemented.

[0097] The fifth embodiment of the present application provides a computer-readable storage medium, which stores computer-executable instructions. When the computer-executable instructions are executed by a control processor, the method for determining the collision coefficient of ice droplets on wind turbine blades provided in the first or second embodiment of the present application is implemented.

[0098] Those skilled in the art will clearly understand that, for the convenience and brevity of description, the specific working processes of the terminals, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0099] In the several embodiments provided in this application, it should be understood that the disclosed terminals, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interface, device or unit, which can be electrical, mechanical or other forms.

[0100] The terms "first", "second", "third", "fourth", etc. (if any) in the specification of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0101] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0102] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected to achieve the purpose of this embodiment according to actual needs.

[0103] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0104] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0105] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for determining the collision coefficient of ice droplets on wind turbine blades, characterized in that: include: According to the coordinate set of the fan blade boundary, combined with the boundary element algorithm, the influence coefficient and disturbance potential data of the fan blade boundary are calculated; Calculating the airflow velocity at a point in the boundary outer field region according to the influence coefficient and the disturbance potential data; Based on the initialized water droplets and the air flow velocity, determining the force state of the water droplets by using a Lagrangian algorithm; According to the force state of the water drop, the movement trajectory of the water drop is tracked, and when the water drop collides with the surface of the fan blade, the collision position and collision speed of the water drop are determined; The local collision coefficient of the water drop collision position is obtained according to the collision speed, the normal vector of the collision position and the airflow speed in combination with a calculation formula for the local collision coefficient of the water drop.

2. A method for determining the collision coefficient of ice droplets on wind turbine blades according to claim 1, characterized in that: The calculation formula for the local collision coefficient of water droplets is specifically: In the formula, β1 P is the local collision coefficient of the water droplet P, V x is the x-axis component of the collision velocity, V y is the y-axis component of the collision velocity, U is the airflow velocity, n jx is the x-axis component of the normal vector of the blade surface that the water drop hits, n jy is the y-axis component of the normal vector of the blade surface that the water drop hits.

3. A method for determining the collision coefficient of ice droplets on wind turbine blades according to claim 1, characterized in that: The step of calculating the airflow velocity at a point in the boundary outer field region according to the influence coefficient and the disturbance potential data specifically includes: According to the influence coefficient and the disturbance potential data, combined with the parameter relationship between the influence coefficient and the disturbance potential data, the flow field disturbance potential data of the flow field area outside the boundary is calculated; According to the parameter relationship between the flow field disturbance potential data and the airflow velocity, the airflow velocity at the point in the boundary outer field area is calculated.

4. The method for determining the collision coefficient of ice droplets on wind turbine blades according to claim 1, characterized in that: Before calculating the influence coefficient of the fan blade boundary and the disturbance potential data in combination with the boundary element algorithm, the method further includes: According to the coordinate set of the boundary of the fan blade, the coordinate points of the boundary of the fan blade are interpolated by a linear interpolation method to obtain the coordinate set of the boundary of the fan blade after interpolation processing.

5. The method for determining the collision coefficient of ice droplets on wind turbine blades according to claim 1, characterized in that: Tracking the motion trajectory of the water droplet according to the stress state of the water droplet, and determining the collision position and collision speed of the water droplet when the water droplet collides with the surface of the fan blade specifically includes: According to the initial position, initial velocity and force state of the water drop, combined with a preset time step, calculate the real-time position of the water drop after the time step; According to the position of the water drop, the collision state of the water drop with the surface of the fan blade is determined by the vector judgment method. When the water drop collides with the surface of the fan blade, the collision position and collision speed of the water drop are determined. If no collision occurs, based on the current position, the preset time step is continued to be combined to calculate the real-time position of the water drop after the time step.

6. A method for determining the collision coefficient of ice droplets on wind turbine blades according to claim 5, characterized in that: The process of tracking the motion trajectory of the water droplet also includes: According to the motion trajectory of the water droplet and in combination with a preset motion trajectory smoothness value, when the smoothness of the motion trajectory is lower than the condition of the motion trajectory smoothness value, the time step is reduced until the smoothness of the motion trajectory is not lower than the motion trajectory smoothness value.

7. A method for determining the collision coefficient of ice droplets on wind turbine blades according to claim 6, characterized in that: The process of tracking the motion trajectory of the water droplet also includes: According to the distance between the current position of the water droplet and the surface of the wind turbine blade, when the distance is greater than a preset distance threshold and the smoothness of the motion trajectory is not less than the motion trajectory smoothness value, the time step is increased.

8. A device for determining the collision coefficient of ice droplets on wind turbine blades, characterized in that: include: A boundary metadata calculation unit, used to calculate the influence coefficient and disturbance potential data of the fan blade boundary according to the coordinate set of the fan blade boundary in combination with the boundary element algorithm; A flow field airflow velocity calculation unit, used to calculate the airflow velocity of a point in the boundary outer field area according to the influence coefficient and the disturbance potential data; A water drop force analysis unit, used to determine the force state of the water drop by using a Lagrangian algorithm based on the initialized water drop and the airflow velocity; A motion trajectory tracking unit, used to track the motion trajectory of the water droplet according to the force state of the water droplet, and determine the collision position and collision speed of the water droplet when the water droplet collides with the surface of the fan blade; The local collision coefficient calculation unit is used to obtain the local collision coefficient of the water drop collision position according to the collision speed, the normal vector of the collision position and the airflow speed in combination with the water drop local collision coefficient calculation formula.

9. A terminal for determining the collision coefficient of ice droplets on wind turbine blades, characterized in that: include: Memory and processor; The memory stores a computer program executable on the processor; When the processor executes the computer program, the method for determining the collision coefficient of ice droplets on wind turbine blades according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium storing computer-executable instructions, characterized in that: When the computer executable instructions are executed by the control processor, the method for determining the collision coefficient of ice droplets on wind turbine blades according to any one of claims 1 to 7 is implemented.

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