External flow field analysis method and device for insulator cleaning through laser carried by unmanned aerial vehicle

Abstract

The invention provides an external flow field analysis method and device for insulator cleaning of a laser carried by an unmanned aerial vehicle. The method comprises the following steps: importing a pre-established three-dimensional geometric model of the laser carried by the unmanned aerial vehicle into a fluid-thermal transient analysis system; determining a fluid domain of the three-dimensional geometric model based on a fluid-thermal transient analysis system; performing grid division on the fluid domain to obtain a grid fluid domain; determining material attributes of the unmanned aerial vehicle and the laser and boundary parameters and initial parameters of a fluid domain; based on a fluid-thermal transient analysis system, determining a simulation scene in which the unmanned aerial vehicle carries the laser to clean the insulator; and determining an external flow field of the gridding fluid domain based on the simulation scene, the boundary parameters, the initial parameters and the material attributes so as to ensure the attitude stability of the unmanned aerial vehicle, thereby improving the insulator cleaning efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of computational fluid dynamics, and in particular to an external flow field analysis method and device for cleaning insulators using a laser mounted on an unmanned aerial vehicle. Background Art

[0002] Insulators are important components in the power system. In order to maintain the working performance of the insulators, they need to be cleaned frequently to remove dirt on the surface of the insulators.

[0003] At present, in order to reduce the amount of manual labor when cleaning insulators in power systems, drones equipped with lasers are generally used to clean insulators. However, when drones are equipped with lasers to clean insulators, the drones will be affected by airflow disturbances, resulting in unstable flight posture of the drones, which reduces the efficiency of drones equipped with lasers to clean insulators. Summary of the invention

[0004] The present invention provides an external flow field analysis method and device for cleaning insulators with a laser mounted on an unmanned aerial vehicle, so as to solve the technical problem in the prior art that the attitude stability of the unmanned aerial vehicle cannot be maintained during the process of cleaning insulators with a laser mounted on the unmanned aerial vehicle.

[0005] On the one hand, the present invention provides an external flow field analysis method for cleaning insulators using a laser mounted on an unmanned aerial vehicle, comprising: Import the pre-established 3D geometric model of the laser onboard the UAV into the fluid-thermal transient analysis system; Determining a fluid domain of the three-dimensional geometric model based on the fluid-thermal transient analysis system; Meshing the fluid domain to obtain a gridded fluid domain; Determining material properties of the drone and the laser and boundary parameters and initial parameters of the fluid domain; Determine a simulation scenario of the UAV carrying a laser to clean insulators based on the fluid-thermal transient analysis system; The external flow field of the gridded fluid domain is determined based on the simulation scenario, the boundary parameters, the initial parameters and the material properties.

[0006] According to an external flow field analysis method for cleaning insulators using a laser mounted on a drone provided by the present invention, the method imports a pre-established three-dimensional geometric model of the laser mounted on a drone into a fluid-thermal transient analysis system, comprising: Based on the size parameters of the pre-established three-dimensional geometric model of the laser carried by the UAV, an overall flow field is divided in the fluid-thermal transient analysis system; The three-dimensional geometric model is imported into the overall flow field domain.

[0007] According to an external flow field analysis method for cleaning insulators using a laser mounted on an unmanned aerial vehicle provided by the present invention, the fluid domain of the three-dimensional geometric model is determined based on the fluid-thermal transient analysis system, including: Based on the fluid-thermal transient analysis system, determining the rotor fluid domain corresponding to each rotor of the UAV; Separating the base wall shape of the drone base, the laser wall shape of the laser, and the rotor wall shape of the sliding area of ​​each rotor from the overall flow field; Determining a solid domain of the three-dimensional geometric model based on the base wall shape, the laser wall shape and the rotor wall shape; The solid domain is subtracted from the overall flow field domain to obtain the fluid domain of the three-dimensional geometric model.

[0008] According to the external flow field analysis method for cleaning insulators by a laser mounted on an unmanned aerial vehicle provided by the present invention, the meshing of the fluid domain to obtain a meshed fluid domain includes: Determine the UAV rotor rotation domain and the laser beam emitting region of the laser in the fluid domain; The fluid domain is meshed based on tetrahedral meshes and a patch conformal method, and the meshes of the UAV rotor rotation domain and the laser beam emitting region of the laser are refined to obtain a meshed fluid domain.

[0009] According to an external flow field analysis method for cleaning insulators with a laser mounted on a drone provided by the present invention, the simulation scenario of cleaning insulators with a laser mounted on a drone based on the fluid-thermal transient analysis system includes at least one of the following: Based on the fluid-thermal transient analysis system, a k-ε turbulence model is selected; wherein the k-ε turbulence model is used to analyze the external flow field of the UAV carrying a laser to clean the insulator; Based on the fluid-heat transient analysis system, defining the heat source characteristics of the laser; Based on the fluid-thermal transient analysis system, activating the energy equation in the solver; Based on the fluid-thermal transient analysis system, a laser heat source of a laser is set; Based on the fluid-thermal transient analysis system, the parameters of the laser beam emitted by the laser are defined.

[0010] According to the external flow field analysis method for cleaning insulators by a laser mounted on an unmanned aerial vehicle provided by the present invention, the k-ε turbulence model is expressed by the following formula:

[0011]

[0012] in, k represents the turbulent kinetic energy, represents the operator, d Indicates the distance from the center of the light spot, ρ represents the fluid density, u represents the molecular viscosity, u t represents the turbulent viscosity, P k represents the term of turbulent kinetic energy generation, P b represents the buoyancy generation term, represents the turbulent kinetic energy dissipation rate, represents the correction term in the turbulence model, represents the turbulent energy term, Indicates i The spatial coordinates in the direction, represents the turbulent viscosity, represents the turbulent kinetic energy number, t Indicates time.

[0013] According to the external flow field analysis method for cleaning insulators by a laser carried by an unmanned aerial vehicle provided by the present invention, based on the fluid-thermal transient analysis system, a laser heat source of the laser is set, including: Introducing Gaussian distribution laser heat source; Define the heat flux density distribution of the laser heat source; Set the laser power density of the laser heat source and the spatial distribution of the laser heat source.

[0014] According to the external flow field analysis method for cleaning insulators by a laser mounted on an unmanned aerial vehicle provided by the present invention, the Gaussian distribution laser heat source is expressed by the following formula:

[0015] in, P(ρ) Indicates that the radius from the center of the heat source is ρ The power density at P e is the power density at the center of the laser heat source, is the heat source distribution width parameter, which represents the distance from the center of the heat source to any point.

[0016] According to the external flow field analysis method for cleaning insulators using a laser mounted on an unmanned aerial vehicle provided by the present invention, the shape of the overall flow field is a cylindrical shape.

[0017] On the other hand, the present invention also provides an external flow field analysis device for cleaning insulators using a laser mounted on an unmanned aerial vehicle, comprising: Model import module, used to import the pre-established 3D geometric model of the laser onboard the UAV into the fluid-thermal transient analysis system; A fluid domain determination module, used for determining the fluid domain of the three-dimensional geometric model based on the fluid-thermal transient analysis system; A grid division module, used for performing grid division on the fluid domain to obtain a gridded fluid domain; A parameter determination module, used to determine the material properties of the UAV and the laser and the boundary parameters and initial parameters of the fluid domain; A simulation scenario determination module, used to determine a simulation scenario of the UAV carrying a laser to clean insulators based on the fluid-thermal transient analysis system; The external flow field analysis module is used to determine the external flow field of the gridded fluid domain based on the simulation scenario, the boundary parameters, the initial parameters and the material properties.

[0018] On the other hand, the present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, an external flow field analysis method for cleaning insulators using a laser mounted on an unmanned aerial vehicle as described in any one of the above methods is implemented.

[0019] The external flow field analysis method and device for cleaning insulators with a laser mounted on a drone provided by the present invention determines the fluid domain of a three-dimensional geometric model based on a fluid-thermal transient analysis system, meshes the fluid domain, and obtains a gridded fluid domain, which is beneficial to improving the calculation efficiency of subsequent steps and the accuracy and reliability of the calculation results. The material properties of the drone and the laser, as well as the boundary parameters and initial parameters of the fluid domain, are determined, and the simulation scenario of the drone carrying a laser to clean insulators is determined based on the fluid-thermal transient analysis system. The external flow field of the gridded fluid domain is determined based on the simulation scenario, boundary parameters, initial parameters, and material properties, so that the disturbance effect of the laser on the external flow field of the drone when emitting the laser can be evaluated, and data support is provided for the development of a control strategy for adjusting the flight attitude of the drone to maintain the stable state of the drone flight, thereby improving the accuracy and efficiency of the laser cleaning of insulators. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present invention or 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 some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1It is a flow chart of an external flow field analysis method for cleaning insulators using a laser carried by an unmanned aerial vehicle provided by an embodiment of the present invention; Figure 2 is a schematic diagram of fluid domain mesh division provided by an embodiment of the present invention; Figure 3 is a structural schematic diagram of an external flow field analysis device for cleaning insulators using a laser mounted on an unmanned aerial vehicle provided in an embodiment of the present invention; Figure 4 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Figure 1 The figure is a flow chart of an external flow field analysis method for cleaning insulators by using a laser mounted on a drone provided by an embodiment of the present invention. The execution subject of the method can be a computer, a mobile phone or a smart wearable device.

[0024] Specifically, the method may include the following steps 101 to 106 .

[0025] 101. Import the pre-established three-dimensional geometric model of the laser mounted on the UAV into the fluid-thermal transient analysis system.

[0026] In this step, the fluid-thermal transient analysis system, namely the ANSYS (finite element analysis) fluid flow and transient thermal analysis system. The ANSYS fluid flow and transient thermal analysis system can be connected in advance through Data Transfer to ensure that the model and data can be transferred between the two. The number of rotors of the drone is not specifically limited, for example, it can generally be a quad-rotor, a hexacopter, an octacopter, etc.

[0027] 102. Based on the fluid-thermal transient analysis system, determine the fluid domain of the three-dimensional geometric model.

[0028] In this step, the fluid domain of the three-dimensional geometric model is determined based on the fluid-thermal transient analysis system. The main purpose is to more accurately simulate and analyze the aerodynamic performance and heat transfer characteristics of the UAV in the external flow field.

[0029] 103. Grid the fluid domain to obtain a gridded fluid domain.

[0030] In this step, the fluid domain is meshed to obtain a meshed fluid domain, which is beneficial to improving the calculation efficiency of subsequent steps and the accuracy and reliability of the calculation results.

[0031] 104. Determine the material properties of the drone and laser as well as the boundary parameters and initial parameters of the fluid domain.

[0032] In this step, material properties may include not only the material properties of the drone and the laser, but also the material properties of the air. Material properties may specifically include density, viscosity, thermal conductivity, etc. Boundary parameters may include flow parameters of the inlet, outlet, and wall. Initial parameters may include the initial position and initial velocity of the drone, etc. Specifically, the wall of the fluid domain divided by each rotor of the drone is set as a moving wall, which rotates relative to the adjacent boundary; the surface of the drone is set as a no-slip wall to simulate the viscosity effect; the pressure outlet is set to the ambient pressure (such as atmospheric pressure) to ensure that the fluid flows out of the calculation domain smoothly; when determining the inlet velocity, the wind speed in the actual flight environment (for example, 4m / s) is usually used.

[0033] 105. Based on the fluid-thermal transient analysis system, the simulation scenario of using a UAV equipped with a laser to clean insulators is determined.

[0034] This step 105 may include at least one of the following: Based on the fluid-thermal transient analysis system, the k-ε turbulence model is selected; among them, the k-ε turbulence model is used to analyze the external flow field of the laser cleaning insulator carried by the drone; Based on the fluid-heat transient analysis system, define the heat source characteristics of the laser; Based on the fluid-thermal transient analysis system, activate the energy equation in the solver; Based on the fluid-thermal transient analysis system, the laser heat source of the laser is set; Based on the fluid-thermal transient analysis system, the laser beam parameters emitted by the laser are defined.

[0035] 106. Determine the external flow field of the gridded fluid domain based on the simulation scenario, boundary parameters, initial parameters and material properties.

[0036] In this step, in the process of determining the external flow field, calculations can be performed according to a preset number of iterative calculations. In the process of iterative calculations, the residuals can be monitored, and whether the calculations have converged can be determined by monitoring the changes in the residuals. Generally, when the residuals are reduced to a certain level, it can be considered that the simulation calculation of the external flow field has converged. This step can be achieved by setting up a transient solver, for example, setting the time list of the transient solver, debugging a suitable calculation output time step, monitoring the residual graph, and determining the convergence conditions; defining the time step and total simulation time of the transient analysis to ensure that the dynamic external flow field changes of the drone are captured during the laser cleaning process.

[0037] In this embodiment, based on the fluid-thermal transient analysis system, the fluid domain of the three-dimensional geometric model is determined, and the fluid domain is meshed to obtain a meshed fluid domain, which is conducive to improving the calculation efficiency of subsequent steps and the accuracy and reliability of the calculation results. The material properties of the drone and the laser, as well as the boundary parameters and initial parameters of the fluid domain are determined, and the simulation scenario of the drone equipped with a laser to clean insulators is determined based on the fluid-thermal transient analysis system. The external flow field of the meshed fluid domain is determined based on the simulation scenario, boundary parameters, initial parameters and material properties, so that the disturbance effect of the laser on the external flow field of the drone when emitting the laser can be evaluated, and data support is provided for the development of a control strategy for adjusting the flight attitude of the drone to maintain the stable state of the drone flight, thereby improving the accuracy and efficiency of the laser cleaning insulator operation.

[0038] In one embodiment of the present specification, importing a pre-established three-dimensional geometric model of a laser mounted on a drone into a fluid-thermal transient analysis system may include: Based on the size parameters of the pre-established three-dimensional geometric model of the laser carried by the UAV, an overall flow field is divided in the fluid-thermal transient analysis system; Import the 3D geometry model into the global flow field domain.

[0039] In this embodiment, the size of the overall flow field needs to be larger than the size of the three-dimensional geometric model, that is, the size of the overall flow field needs to be large enough to ensure the accuracy of the boundary conditions. In addition, the shape of the overall flow field can be a cylindrical shape. The cylindrical shape provides a relatively simple geometric shape, which is convenient for setting boundary conditions and meshing, thereby simplifying the calculation process. Compared with other shapes, the cylinder can reduce the complexity of calculation in fluid dynamics simulation, so that computing resources and time are more effectively utilized. The size parameters of the three-dimensional geometric model may include a main body length (for example, 0.8m), a main body width (for example, 0.8m), a main body height (for example, 0.3m) and a propeller diameter (for example, 0.4m), etc.

[0040] In one embodiment of the present specification, determining the fluid domain of the three-dimensional geometric model based on the fluid-thermal transient analysis system may include: Based on the fluid-thermal transient analysis system, determine the rotor fluid domain corresponding to each rotor of the UAV; The base wall shape of the drone base, the laser wall shape of the laser, and the rotor wall shape of the sliding area of ​​each rotor are separated from the overall flow field; Determine the solid domain of the three-dimensional geometric model based on the base wall shape, the laser wall shape and the rotor wall shape; The solid domain is subtracted from the global flow domain to obtain the fluid domain of the 3D geometry model.

[0041] In this embodiment, determining the rotor fluid domain corresponding to each rotor of the drone can more accurately simulate the interaction between the rotor and the surrounding air, thereby improving the accuracy of the flight stability analysis. Determining the solid domain can simulate the interaction between the fluid and the solid, which helps to more clearly define the scope of the fluid domain and provide accurate boundary conditions for fluid mechanics analysis. The determination of the fluid domain is based on the shape of the solid domain, which can more realistically simulate the flight state of the drone in the actual environment and improve the accuracy of the simulation.

[0042] In general, the fluid domain corresponding to each rotor can be defined through the Design Modeler in the fluid-thermal transient analysis system. The base wall shape of the drone base, the laser wall shape of the laser, and the rotor wall shape of the slip zone of each rotor can be separated from the overall flow field through Boolean operations and selection extraction operations.

[0043] After subtracting the solid domain from the overall flow field to obtain the fluid domain of the 3D geometric model, the boundaries of the fluid domain can be defined, such as the inlet, outlet, and wall boundary conditions. Inlet boundary conditions are usually used to define the velocity or flow rate of the fluid entering the computational domain. Define the velocity vector of the fluid entering the computational domain. For example, the wind speed in the actual UAV flight environment can be simulated by setting the inlet velocity. The fluid temperature at the inlet is defined as room temperature (e.g. 22°C).

[0044] Outlet boundary conditions are used to define the conditions for fluid to leave the computational domain. For example, setting the pressure outlet to the ambient atmospheric pressure ensures that the fluid can flow out of the computational domain smoothly. This is to simulate an open boundary, so that the fluid in the computational domain can flow out freely without restriction.

[0045] Wall boundary conditions are used to define the interaction between the fluid and the solid surface. The wall boundary conditions may include at least one of no-slip conditions, moving walls, heat flux, etc. The way to define a no-slip condition includes: setting the surface of the drone to a no-slip wall to simulate the viscous effect, which means that the velocity of the fluid is zero when it contacts the solid surface, reflecting the actual physical situation. The way to define a moving wall includes: setting the wall of the fluid domain divided by each rotor of the drone to a moving wall, so that the moving wall rotates relative to the adjacent boundary to simulate the movement of the rotor and affect the surrounding flow field. In addition, the reason for defining the heat flux or temperature condition is that the heat emitted by the laser will cause the temperature of the surrounding air to rise, and this heat transfer can be quantified by the heat flux.

[0046] In one embodiment of the present specification, meshing the fluid domain to obtain a meshed fluid domain may include: Determine the UAV rotor rotation domain and the laser beam emitting area in the fluid domain; The fluid domain is meshed based on tetrahedral mesh and patch conformal method, and the meshes of the UAV rotor rotation domain and the laser beam emitting area are refined to obtain a meshed fluid domain.

[0047] In this embodiment, the meshing results of the fluid domain based on tetrahedral mesh and patch conformal method can be seen in Figure 2 . Tetrahedral mesh is used as the shape of the mesh. The patch conformal method is used to define the size of the mesh. Tetrahedral mesh has strong flexibility and adaptability to complex geometric shapes, which allows for more detailed discretization of the fluid domain while maintaining the quality of the mesh. Mesh refinement (which can also be understood as mesh encryption) of the UAV rotor rotation domain and the laser beam area can better capture the flow characteristics and interactions of these areas, more accurately simulate the flow behavior of these complex areas, and improve the accuracy of external flow field analysis. In addition, the overall geometric dimensions of the three-dimensional geometric model can be constrained to ensure the accuracy of the mesh division, so that the simulation results are closer to the actual situation. In the external flow field analysis of UAVs, an accurate geometric model is the basis for obtaining reliable simulation results.

[0048] In one embodiment of the present specification, the k-ε turbulence model can be expressed by the following formula (1), and the heat source characteristics of the laser can be expressed by the following formula (2): Formula (1).

[0049] Formula (2).

[0050] in, k represents the turbulent kinetic energy, represents the operator,d Indicates the distance from the center of the light spot, ρ represents the fluid density, u represents the molecular viscosity, u t represents the turbulent viscosity, P k represents the term of turbulent kinetic energy generation, P b represents the buoyancy generation term, represents the turbulent kinetic energy dissipation rate, represents the correction term in the turbulence model, represents the turbulent energy term, Indicates i The spatial coordinates in the direction, represents the turbulent viscosity, represents the turbulent kinetic energy number, t Indicates time.

[0051] In this embodiment, formula (1) represents the transmission equation of turbulent kinetic energy of the k−ϵ turbulence model, and formula (2) represents the transmission equation of turbulent kinetic energy dissipation rate. Formula (1) and formula (2) describe the turbulent characteristics, and are used to establish and solve the discretization equations of the fluid domain in computational fluid dynamics (CFD) simulation, which is conducive to converting continuous fluid dynamics problems into discrete numerical problems, and can ensure the accuracy and efficiency of the analysis. In other words, formula (1) and formula (2) are also equivalent to discretization equations. In this embodiment, the heat transfer field can also be defined. For example, the laser power density (e.g., 18 W), laser spot radius (e.g., 2.5 mm), specific heat (e.g., 1200 J / (kgK)), sublimation heat (e.g., 500 KJ / kg), etc. can be set. In addition, the operational equation of the turbulence model can be expressed by formula (3).

[0052] (3) Among them, in formula (3) , , is expressed as the turbulence model constant, Expressed as the source term of turbulent kinetic energy dissipation rate, v i Expressed as i Furthermore, the unit area can be set for each rotor rotation of the drone, for example, selecting grid motion, setting the origin coordinates of the rotor rotation axis, etc.

[0053] In one embodiment of the present specification, based on the fluid-thermal transient analysis system, setting a laser heat source of a laser may include: Introducing Gaussian distribution laser heat source; Use UDF (user defined function) to define the heat flux density distribution of the laser heat source; Set the laser power density of the laser heat source and the spatial distribution of the laser heat source.

[0054] In this embodiment, when analyzing the external flow field of the UAV, a Gaussian distribution laser heat source is introduced, which can simulate the distribution characteristics of the laser beam in space. Generally, a Gaussian distribution laser heat source can be described by a mathematical expression, such as using a Gaussian function to represent the change of laser power density with spatial position. By introducing a Gaussian distribution laser heat source, the thermal effect in the laser cleaning process can be simulated more accurately, thereby improving the accuracy of the analysis.

[0055] User-defined functions (UDFs) are a feature in CFD software such as ANSYS Fluent that allows users to customize physical processes according to specific needs. The heat flux density distribution of the laser heat source is defined by writing a UDF. UDFs can contain parameters such as laser power, wavelength, divergence angle, and a physical model of the interaction between the laser and the material, thereby achieving precise control of the characteristics of the laser heat source. User-defined functions (UDFs) can flexibly define the heat flux density distribution of the laser heat source to meet the needs of different insulator cleaning and enhance the controllability of the cleaning process.

[0056] When setting the laser power density and spatial distribution of the laser heat source, it usually involves determining the laser power, spot size, focal length and other parameters of the laser, as well as the distribution of the laser beam on the surface of the UAV. By adjusting these parameters, the effect of the laser heat source on the external flow field of the UAV can be simulated, including changes in heat transfer and aerodynamic performance. By setting the power density and spatial distribution of the laser heat source, the cleaning effect can be optimized to ensure the uniformity and efficiency of the cleaning process while reducing potential damage to the insulator. The above steps together improve the accuracy and efficiency of the external flow field analysis of insulator cleaning using UAV-mounted lasers, which helps to achieve higher quality cleaning operations. In specific implementation, it may be necessary to combine the geometric model and material properties of the UAV and use CFD software for numerical simulation to obtain detailed data on the effect of the laser heat source on the external flow field of the UAV.

[0057] In one embodiment of the present specification, the Gaussian distribution laser heat source can be expressed by the following formula (4): Formula (4).

[0058] Among them, in formula (4) P(ρ) Indicates that the radius from the center of the heat source is ρ The power density at P e is the power density at the center of the laser heat source, is the heat source distribution width parameter, which represents the distance from the center of the heat source to any point. The Gaussian distribution laser heat source can describe the distribution of laser power density in space and is used to define how the intensity of the laser heat source changes with distance.

[0059] In some other embodiments of the present invention, determining the simulation scenario of the UAV carrying the laser to clean the insulator based on the fluid-thermal transient analysis system may also include: Establish heat conduction and convection equations to simulate the temperature change in the air fluid during laser heating; The heat conduction and convection equations can be expressed by the following formula (5): Formula (5).

[0060] Among them, in formula (5) is the density of the fluid, is the specific heat capacity of air, is the temperature field, is the air velocity vector, is the thermal conductivity of air, is the laser heat source term, t Considering the influence of heat conduction, convection and laser heat source on the temperature field, the temperature change in the air fluid during the laser heating process is simulated by heat conduction and convection equations.

[0061] In some other embodiments of the present invention, determining the simulation scenario of the UAV carrying the laser to clean the insulator based on the fluid-thermal transient analysis system may also include: Establish the laser heat source equation to simulate the energy attenuation of the laser when it propagates in the air; The laser heat source term equation that simulates the energy attenuation of laser when propagating in air can be expressed by formula (6): Formula (6).

[0062] in, is the absorption coefficient of laser in fluid, is the incident laser intensity, is the depth of laser propagation in the fluid. The laser heat source term equation that simulates the energy attenuation of laser propagation in the air can be used to calculate the energy absorption of the laser at different depths.

[0063] In one embodiment of the present invention, based on the fluid-thermal transient analysis system, defining the laser beam parameters emitted by the laser may include: The initial position of the laser beam (x-, y- and z-coordinates of the center of the laser beam), heat flux density, beam radius, etc.

[0064] In some other embodiments of the present invention, determining the simulation scenario of the UAV carrying the laser to clean the insulator based on the fluid-thermal transient analysis system may also include: Establish the equation of heat transfer of laser in air fluid, simulate and analyze the overall process of heat transfer of laser in air fluid; Formula (7).

[0065] In this embodiment, the above formulas (4) to (7) can be used to accurately predict and analyze the thermal interaction effect between the laser and the fluid in simulation.

[0066] In some other embodiments of the present specification, based on the fluid-thermal transient analysis system, the energy equation in the solver is activated. Specifically, it can be set in the "Solution" panel to ensure that the "Energy" equation is turned on.

[0067] In some other embodiments of this specification, the external flow field analysis method for cleaning insulators using a laser mounted on an unmanned aerial vehicle may also include: The heat transfer module defines the laser heat source through heat flux definition or using the "Volume Heat Source" model: through ANSYS custom UDF function, use the DEFINE_SOURCE function in the UDF to define the volume heat source, and set parameters according to the characteristics of the laser, such as laser power, action time, and spatial distribution.

[0068] In some other embodiments of the present specification, selecting a k-ε turbulence model based on a fluid-thermal transient analysis system, and defining heat source characteristics of a laser based on the fluid-thermal transient analysis system may both belong to setting a physical model.

[0069] Setting the physical model (selecting the k-ε turbulence model based on the fluid-thermal transient analysis system; defining the heat source characteristics of the laser based on the fluid-thermal transient analysis system) may specifically include: Step 1: Select the physical model and set the relevant parameters. Select the commonly used k−ϵ turbulence model.

[0070] Set the relevant parameters of the turbulence model, such as turbulent kinetic energy and turbulent kinetic energy dissipation rate.

[0071] Define the heat transfer field: Enable the energy equation and define the heat transfer properties for the fluid and solid domains. Set the heat source properties for the laser, including heat flux or volume heat source, to simulate the heating effect of the laser.

[0072] Step 2: Set the rotor's mesh motion and rotation axis: Set the unit area for each rotor: Identify and segment the rotor region in the geometric model to ensure the independence and mesh quality of the rotor region.

[0073] Select the mesh motion: Set the mesh motion in the rotor area to ensure that the rotor can correctly simulate the rotational motion during simulation.

[0074] Select the appropriate mesh motion type to simulate the actual motion state of the rotor.

[0075] Set the rotor rotation axis origin coordinates: Define the rotor's rotation axis and origin coordinates so that the rotor rotates according to the predetermined axis and position during the simulation.

[0076] The connection between step one and step two is the relationship between the physical model and the mesh motion.

[0077] The viscosity model selected in step 1 determines the physical properties of the fluid and solid domains. These physical properties need to be taken into account when setting the mesh motion in step 2. For example, the parameter settings of the turbulence model affect the fluid flow characteristics in the rotor area, while the heat transfer field settings affect the temperature distribution and heat conduction in the rotor area.

[0078] Coordination of rotor area division and physical model: In step 2, the unit area of ​​the rotor is set to ensure that the physical model parameters defined in step 2 can be accurately applied in the rotor area. The independence and mesh quality of the rotor area directly affect the calculation accuracy of the turbulence model and the heat transfer model.

[0079] The mesh motion setting of the rotor area needs to take into account the fluid and heat transfer characteristics defined in step 1 to ensure that the impact of the rotor on the flow field and temperature field during movement can be accurately simulated.

[0080] Rotation axis setting and flow field characteristics: In step 2, the origin coordinates of the rotor's rotation axis are set to ensure that the rotor can accurately simulate the rotational motion during the simulation process.

[0081] In summary, the present invention mainly simulates the impact of the laser heat source on the external flow field of the drone when the laser emits, and predicts the possible flow field disturbance during the laser cleaning operation. When the drone does not start the laser, the flow field distribution is relatively uniform, the surrounding air flows smoothly, and the pressure and velocity field distribution is stable. After the laser emits the laser, the laser beam heats the surrounding air, resulting in a decrease in local air density, forming an updraft, and a significant disturbance in the flow field, and a vortex disturbance is generated under the drone. The air velocity in front and on the side of the drone increases, and the pressure distribution changes. Due to the flow field disturbance, the pitch angle and yaw angle of the drone have changed slightly, resulting in a change in attitude. Subsequently, by applying the PID control algorithm, the attitude of the drone can be quickly adjusted and restored to stability after the flow field disturbance occurs. By analyzing the external flow field of the drone, data support is provided for the development of a strategy to adjust the attitude stability of the drone to accurately control the position and direction of the laser beam, ensure the cleaning uniformity of the insulator surface, reduce the cleaning time, and improve the work efficiency. In addition, the corresponding flight path and strategy are formulated to establish a foundation.

[0082] Based on the same general inventive concept, the present invention also protects an external flow field analysis device for cleaning insulators using a laser mounted on an unmanned aerial vehicle, such as Figure 3 As shown. The external flow field analysis device for cleaning insulators by laser mounted on a drone provided by the present invention is described below. The external flow field analysis device for cleaning insulators by laser mounted on a drone described below and the external flow field analysis method for cleaning insulators by laser mounted on a drone described above can be referred to each other. The device may include a model import module 201, a fluid domain determination module 202, a grid division module 203, a parameter determination module 204, a simulation scene determination module 205 and an external flow field analysis module 206.

[0083] The model import module 201 is used to import the pre-established three-dimensional geometric model of the laser carried by the UAV into the fluid-thermal transient analysis system; The fluid domain determination module 202 is used to determine the fluid domain of the three-dimensional geometric model based on the fluid-thermal transient analysis system; The grid division module 203 is used to perform grid division on the fluid domain to obtain a gridded fluid domain; The parameter determination module 204 is used to determine the material properties of the UAV and the laser and the boundary parameters and initial parameters of the fluid domain; The simulation scenario determination module 205 is used to determine the simulation scenario of the UAV carrying the laser to clean the insulator based on the fluid-thermal transient analysis system; The external flow field analysis module 206 is used to determine the external flow field of the gridded fluid domain based on the simulation scenario, the boundary parameters, the initial parameters and the material properties.

[0084] Figure 4 It is a schematic diagram of the structure of an electronic device provided by an embodiment of the present invention.

[0085] like Figure 4 As shown, the electronic device may include: a processor 610, a communication interface 620, a memory 630 and a communication bus 640, wherein the processor 610, the communication interface 620 and the memory 630 communicate with each other through the communication bus 640. The processor 610 may call the logic instructions in the memory 630 to execute the external flow field analysis method of cleaning insulators by a laser mounted on a drone.

[0086] In addition, the logic instructions in the above-mentioned memory 630 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied 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 computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0087] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the external flow field analysis method for cleaning insulators using a laser mounted on a drone provided by the above-mentioned methods.

[0088] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to execute the external flow field analysis method for cleaning insulators using a laser mounted on an unmanned aerial vehicle provided by the above-mentioned methods.

[0089] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0090] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned 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 invention.

Claims

1. An external flow field analysis method for cleaning insulators using a laser mounted on an unmanned aerial vehicle, characterized in that: include: Import the pre-established 3D geometric model of the laser onboard the UAV into the fluid-thermal transient analysis system; Determining a fluid domain of the three-dimensional geometric model based on the fluid-thermal transient analysis system; Meshing the fluid domain to obtain a gridded fluid domain; Determining material properties of the drone and the laser and boundary parameters and initial parameters of the fluid domain; Determine a simulation scenario of the UAV carrying a laser to clean insulators based on the fluid-thermal transient analysis system; The external flow field of the gridded fluid domain is determined based on the simulation scenario, the boundary parameters, the initial parameters and the material properties.

2. The external flow field analysis method for cleaning insulators by a laser mounted on an unmanned aerial vehicle according to claim 1 is characterized in that: The method of importing the pre-established three-dimensional geometric model of the laser carried by the UAV into the fluid-thermal transient analysis system includes: Based on the dimension parameters of the pre-established three-dimensional geometric model of the laser mounted on the UAV, an overall flow field is divided in the fluid-thermal transient analysis system; The three-dimensional geometric model is imported into the overall flow field domain.

3. The external flow field analysis method for cleaning insulators by a laser mounted on an unmanned aerial vehicle according to claim 2 is characterized in that: The step of determining the fluid domain of the three-dimensional geometric model based on the fluid-thermal transient analysis system comprises: Based on the fluid-thermal transient analysis system, determining the rotor fluid domain corresponding to each rotor of the UAV; Separating the base wall shape of the drone base, the laser wall shape of the laser, and the rotor wall shape of the sliding area of ​​each rotor from the overall flow field; Determining a solid domain of the three-dimensional geometric model based on the base wall shape, the laser wall shape and the rotor wall shape; The solid domain is subtracted from the overall flow field domain to obtain the fluid domain of the three-dimensional geometric model.

4. The external flow field analysis method for cleaning insulators by a laser mounted on an unmanned aerial vehicle according to claim 1, characterized in that: The step of meshing the fluid domain to obtain a meshed fluid domain comprises: Determine the UAV rotor rotation domain and the laser beam emitting region of the laser in the fluid domain; The fluid domain is meshed based on tetrahedral meshes and a patch conformal method, and the meshes of the UAV rotor rotation domain and the laser beam emitting region of the laser are refined to obtain a meshed fluid domain.

5. The external flow field analysis method for cleaning insulators by a laser mounted on an unmanned aerial vehicle according to claim 1, characterized in that: The method of determining the simulation scenario of the UAV carrying a laser to clean the insulator based on the fluid-thermal transient analysis system includes at least one of the following: Based on the fluid-thermal transient analysis system, a k-ε turbulence model is selected; wherein the k-ε turbulence model is used to analyze the external flow field of the UAV carrying a laser to clean the insulator; Based on the fluid-heat transient analysis system, defining the heat source characteristics of the laser; Based on the fluid-thermal transient analysis system, activating the energy equation in the solver; Based on the fluid-thermal transient analysis system, a laser heat source of a laser is set; Based on the fluid-thermal transient analysis system, the parameters of the laser beam emitted by the laser are defined.

6. The external flow field analysis method for cleaning insulators by a laser mounted on an unmanned aerial vehicle according to claim 5, characterized in that: The k-ε turbulence model is expressed by the following formula: ； ； in, k represents the turbulent kinetic energy, represents the operator, d Indicates the distance from the center of the light spot, ρ represents the fluid density, u represents the molecular viscosity, u t represents the turbulent viscosity, P k represents the term of turbulent kinetic energy generation, P b represents the buoyancy generation term, represents the turbulent kinetic energy dissipation rate, represents the correction term in the turbulence model, represents the turbulent energy term, Indicates i The spatial coordinates in the direction, represents the turbulent viscosity, represents the turbulent kinetic energy number, t Indicates time.

7. The external flow field analysis method for cleaning insulators by a laser mounted on an unmanned aerial vehicle according to claim 5, characterized in that: Based on the fluid-thermal transient analysis system, a laser heat source of a laser is set, including: Introducing Gaussian distribution laser heat source; Define the heat flux density distribution of the laser heat source; Set the laser power density of the laser heat source and the spatial distribution of the laser heat source.

8. The external flow field analysis method for cleaning insulators using a laser mounted on an unmanned aerial vehicle according to claim 7, characterized in that: The Gaussian distribution laser heat source is expressed by the following formula: ； in, P(ρ) Indicates that the radius from the center of the heat source is ρ The power density at P e is the power density at the center of the laser heat source, is the heat source distribution width parameter, which represents the distance from the center of the heat source to any point.

9. The external flow field analysis method for cleaning insulators by a laser mounted on an unmanned aerial vehicle according to claim 2, characterized in that: The overall flow field is in the shape of a cylinder.

10. An external flow field analysis device for cleaning insulators using a laser mounted on an unmanned aerial vehicle, characterized in that: include: Model import module, used to import the pre-established 3D geometric model of the laser onboard the UAV into the fluid-thermal transient analysis system; A fluid domain determination module, used for determining the fluid domain of the three-dimensional geometric model based on the fluid-thermal transient analysis system; A grid division module, used for performing grid division on the fluid domain to obtain a gridded fluid domain; A parameter determination module, used to determine the material properties of the UAV and the laser and the boundary parameters and initial parameters of the fluid domain; A simulation scenario determination module, used to determine a simulation scenario of the UAV carrying a laser to clean insulators based on the fluid-thermal transient analysis system; The external flow field analysis module is used to determine the external flow field of the gridded fluid domain based on the simulation scenario, the boundary parameters, the initial parameters and the material properties.

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