A method for simulating the dynamic opening and closing characteristics of a flexible umbrella structure with bidirectional fluid-structure coupling

Abstract

The present disclosure relates to a method for simulating the dynamic opening and closing characteristics of a flexible umbrella structure with bidirectional fluid-solid coupling, which is applied to the dynamic simulation of a working umbrella in an umbrella ladder high-altitude wind power generation system. The method comprises: establishing a working umbrella model and a flow field model around the working umbrella; wherein the working umbrella model is constructed based on the lumped mass method; the flow field model is constructed based on the smoothed particle fluid dynamics method; based on the working umbrella model and the flow field model, a bidirectional fluid-solid coupling system is constructed; wherein, in the bidirectional fluid-solid coupling system, there is interaction between the partial components corresponding to the working umbrella model and the partial components corresponding to the flow field model; simulation is performed based on the bidirectional fluid-solid coupling system to solve the dynamic information of the working umbrella model and the dynamic information of the flow field model corresponding to each time step to determine the characteristics of the working umbrella during the dynamic opening and closing process. Through the present disclosure, the dynamic behavior of the working umbrella in a highly dynamic and complex flow field can be simulated efficiently.

Description

Technical Field

[0001] The present disclosure relates to the field of high-altitude wind energy technology, and in particular to a method for simulating the dynamic opening and closing characteristics of a flexible umbrella structure with bidirectional fluid-solid coupling. Background Art

[0002] The parachute-ladder high-altitude power generation system is one of the technological implementation paths in the field of high-altitude wind power generation. As the core load-bearing structure of the parachute-ladder high-altitude power generation system, the dynamic behavior of the working parachute in a strong and complex wind field directly affects the parachute-ladder high-altitude power generation system's ability to generate stable power in high-altitude environments.

[0003] Currently, there is a lack of simulation solutions for the dynamic characteristics of the working parachute in the parachute ladder type high altitude wind energy development system. Summary of the Invention

[0004] In view of this, the present disclosure proposes a method, device, electronic device and storage medium for simulating the dynamic opening and closing characteristics of a flexible umbrella structure with bidirectional fluid-solid coupling.

[0005] According to one aspect of the present disclosure, a method for simulating the dynamic opening and closing characteristics of a flexible umbrella structure with bidirectional fluid-structure coupling is provided, which is applied to the dynamic simulation of a working umbrella in an umbrella ladder high-altitude wind power generation system. The method comprises:

[0006] Establishing a work-doing parachute model and a flow field model around the work-doing parachute; wherein the work-doing parachute model is constructed based on the lumped mass method; and the flow field model is constructed based on the smoothed particle fluid dynamics method;

[0007] Based on the work-doing umbrella model and the flow field model, a bidirectional fluid-solid coupling system is constructed; wherein, in the bidirectional fluid-solid coupling system, there is interaction between some component units corresponding to the work-doing umbrella model and some component units corresponding to the flow field model;

[0008] A simulation is performed based on the bidirectional fluid-solid coupling system to solve the dynamic information of the working umbrella model and the dynamic information of the flow field model corresponding to each time step to determine the characteristics of the working umbrella during the dynamic opening and closing process.

[0009] In a possible implementation, the component unit of the work-doing parachute model includes a plurality of mass points;

[0010] The step of establishing the work-performing umbrella model comprises:

[0011] The work-doing parachute is described using the lumped mass method to obtain the plurality of mass points;

[0012] For any mass point among the plurality of mass points, determining a mechanical unit corresponding to the mass point, wherein the mechanical unit is used to connect the mass point to at least one other mass point among the plurality of mass points; the mechanical unit includes one or more of a bending spring, a shear spring, and a tension spring;

[0013] The work-doing parachute model is established based on the multiple mass points and the mechanical units corresponding to each of the multiple mass points.

[0014] In a possible implementation, the component unit of the flow field model includes a plurality of fluid particles;

[0015] The step of establishing a flow field model around the working parachute comprises:

[0016] determining a target flow field based on the work-doing parachute model, so that the work-doing parachute model is immersed in the target flow field;

[0017] Using the smoothed particle hydrodynamics method, determining a plurality of fluid particles within the target flow field;

[0018] The flow field model is established based on the multiple fluid particles.

[0019] In a possible implementation, performing simulation based on the bidirectional fluid-structure coupling system to solve the dynamic information of the work-doing parachute model and the dynamic information of the flow field model corresponding to each time step includes:

[0020] At any time step, performing penetration detection between each fluid particle in the flow field model and each surface element in the work-doing umbrella model, and between different surface elements in the work-doing umbrella model, wherein any surface element is composed of multiple particles in the work-doing umbrella model;

[0021] Based on the mold penetration detection results, determining the fluid particles and particles that interact with each other in the bidirectional fluid-solid coupling system, as well as the different particles that interact with each other;

[0022] Calculating the force between the interacting fluid particles and the mass points, and the force between the interacting different mass points, by using a penalty function;

[0023] Determining the dynamic information of the flow field model corresponding to the time step based on the interaction forces between the interacting fluid particles and the mass points and the interaction forces between the fluid particles in the flow field model;

[0024] Based on the forces between the interacting fluid particles and the mass points, the forces between the interacting different mass points, and the forces of the mechanical units corresponding to the mass points in the work-doing umbrella model, the dynamic information of the work-doing umbrella model corresponding to the time step is determined.

[0025] In one possible implementation, determining the dynamic information of the flow field model corresponding to the time step based on the forces between the interacting fluid particles and the mass points and the forces between the fluid particles in the flow field model includes:

[0026] Performing a neighborhood search for each fluid particle in the flow field model, and updating a density attribute of the fluid particle according to the neighborhood search result;

[0027] Update the pressure attribute of the fluid particle according to the density attribute of the fluid particle;

[0028] Determining the force between the fluid particle and other fluid particles based on the current velocity of the fluid particle, the density attribute, the pressure attribute, and the viscosity attribute;

[0029] Based on the interaction force between the fluid particle and other fluid particles and the interaction force between the fluid particle and the mass point in the work-doing umbrella model, the dynamic information of the fluid particle corresponding to the time step is determined.

[0030] In one possible implementation, determining the dynamic information of the work-doing umbrella model corresponding to the time step based on the forces between the interacting fluid particles and the mass points, the forces between the interacting different mass points, and the forces of the mechanical units corresponding to the mass points in the work-doing umbrella model includes:

[0031] For each mass point in the work-doing parachute model, determine the force of the mechanical unit corresponding to the mass point based on the force of the tension spring, the force of the shear spring, and the force of the bending spring borne by the mass point;

[0032] Determining the force between the particle and the fluid particles in the flow field model, and the force between the particle and the particle in the work-doing umbrella model;

[0033] Based on the force of the mechanical unit corresponding to the particle, the force between the particle and the fluid particles in the flow field model, and the force between the particle and the particles in the work umbrella model, the dynamic information of the particle corresponding to the time step is determined.

[0034] In a possible implementation, the step size corresponding to each time step is determined by the density of fluid particles in the target flow field.

[0035] According to another aspect of the present disclosure, a device for simulating the dynamic opening and closing characteristics of a flexible umbrella structure with bidirectional fluid-solid coupling is provided, which is applied to the dynamic simulation of a working umbrella in an umbrella ladder-type high-altitude wind power generation system. The device comprises:

[0036] A modeling module, for establishing a work-doing parachute model and a flow field model around the work-doing parachute; wherein the work-doing parachute model is constructed based on the lumped mass method; and the flow field model is constructed based on the smoothed particle hydrodynamics method;

[0037] The modeling module is further configured to construct a bidirectional fluid-solid coupling system based on the work-doing umbrella model and the flow field model; wherein, in the bidirectional fluid-solid coupling system, there is interaction between some component units corresponding to the work-doing umbrella model and some component units corresponding to the flow field model;

[0038] A simulation module is used to perform simulation based on the bidirectional fluid-solid coupling system to solve the dynamic information of the working umbrella model and the dynamic information of the flow field model corresponding to each time step, so as to determine the characteristics of the working umbrella during the dynamic opening and closing process.

[0039] According to another aspect of the present disclosure, an electronic device is provided, comprising: a processor; and a memory for storing processor-executable instructions; wherein the processor is configured to implement the above method when executing the instructions stored in the memory.

[0040] According to another aspect of the present disclosure, a non-volatile computer-readable storage medium is provided, on which computer program instructions are stored, wherein the computer program instructions implement the above method when executed by a processor.

[0041] According to another aspect of the present disclosure, a computer program product is provided, including a computer-readable code, or a non-volatile computer-readable storage medium carrying the computer-readable code. When the computer-readable code runs in a processor of an electronic device, the processor in the electronic device executes the above method.

[0042] Through various aspects of the present disclosure, a work-operating parachute model and a flow field model surrounding the work-operating parachute are established; wherein the work-operating parachute model is constructed based on the lumped mass method; the flow field model is constructed based on the smoothed particle fluid dynamics method; based on the work-operating parachute model and the flow field model, a bidirectional fluid-structure coupling system is constructed; wherein, in the bidirectional fluid-structure coupling system, there is interaction between the components corresponding to the work-operating parachute model and the components corresponding to the flow field model; based on the bidirectional fluid-structure coupling system, a simulation is performed to solve the dynamic information of the work-operating parachute model and the dynamic information of the flow field model corresponding to each time step to determine the characteristics of the work-operating parachute during the dynamic opening and closing process. This thereby realizes the dynamic simulation of the work-operating parachute in the parachute ladder high-altitude wind power generation system. In this way, a power parachute model is constructed based on the lumped mass method, and a flow field model around the power parachute is constructed based on the smoothed particle fluid dynamics method, achieving Lagrangian particle modeling of both the parachute body and the surrounding fluid in the bidirectional fluid-solid coupling system. Furthermore, a multiple time-stepping strategy is employed to couple and solve the bidirectional fluid-solid coupling system, solving the dynamic information of the power parachute model and the dynamic information of the flow field model corresponding to each time step, thereby determining the characteristics of the power parachute during the dynamic opening and closing process. Compared to traditional simulation methods, the method in the disclosed embodiment can complete a highly accurate simulation of the dynamic behavior of the power parachute in a highly dynamic and complex wind field in a shorter time. Furthermore, the flow field changes around the power parachute can be obtained. This method can be applied to the analysis and prediction of power parachute operating conditions in actual engineering projects, thereby better assisting the design and operation optimization of land-based high-altitude wind power generation systems and promoting the development of new energy and other fields.

[0043] Further features and aspects of the present disclosure will become apparent from the following detailed description of exemplary embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments, features, and aspects of the disclosure and, together with the description, serve to explain the principles of the disclosure.

[0045] Figure 1 A schematic structural diagram of a land-based high-altitude wind power generation system according to an embodiment of the present disclosure is shown.

[0046] Figure 2 A flowchart of a method for simulating the dynamic opening and closing characteristics of a flexible umbrella structure with bidirectional fluid-solid coupling according to an embodiment of the present disclosure is shown.

[0047] Figure 3 A schematic structural diagram of a working umbrella in a folded state according to an embodiment of the present disclosure is shown.

[0048] Figure 4A schematic structural diagram of a power-producing parachute in a fully opened state according to an embodiment of the present disclosure is shown.

[0049] Figure 5 A structural diagram of a bidirectional fluid-structure coupling system according to an embodiment of the present disclosure is shown.

[0050] Figure 6 A schematic diagram illustrating simulation results of a dynamic change process of a power parachute according to an embodiment of the present disclosure is shown.

[0051] Figure 7 A flow chart of a method for performing simulation based on a bidirectional fluid-structure coupling system according to an embodiment of the present disclosure is shown.

[0052] Figure 8 Schematic diagram showing a working umbrella in a closed state and an open state according to an embodiment of the present disclosure.

[0053] Figure 9 A flowchart of a simulation according to an embodiment of the present disclosure is shown.

[0054] Figure 10 A structural diagram of a device for simulating the dynamic opening and closing characteristics of a flexible umbrella structure with bidirectional fluid-solid coupling according to an embodiment of the present disclosure is shown.

[0055] Figure 11 A block diagram of an electronic device 1900 according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0056] Various exemplary embodiments, features, and aspects of the present disclosure will be described in detail below with reference to the accompanying drawings. The same reference numerals in the accompanying drawings represent elements with the same or similar functions. Although various aspects of the embodiments are shown in the accompanying drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0057] References to "one embodiment" or "some embodiments" in this specification mean that a particular feature, structure, or characteristic described in conjunction with that embodiment is included in one or more embodiments of the present disclosure. Thus, phrases such as "exemplary," "in one embodiment," "in some other embodiments," and "in other embodiments" appearing in various places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized.

[0058] In the present disclosure, "at least one" means one or more, and "more than one" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can mean: including the existence of A alone, the existence of A and B at the same time, and the existence of B alone, 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, ab, ac, bc, or abc, where a, b, c can be single or multiple.

[0059] In addition, numerous specific details are provided in the following detailed description to better illustrate the present disclosure. Those skilled in the art will appreciate that the present disclosure can be practiced without certain specific details. In some instances, methods, means, components, and circuits well known to those skilled in the art are not described in detail in order to highlight the main points of the present disclosure.

[0060] First, possible application scenarios of the power umbrella simulation method according to the embodiment of the present disclosure are exemplarily described below.

[0061] Figure 1 FIG. 1 shows a schematic structural diagram of a land-based high-altitude wind power generation system according to an embodiment of the present disclosure. Figure 1 As shown, the land-based high-altitude wind energy power generation system may include: an aerial device and a ground device;

[0062] For example, aerial devices may include helium balloons, powered parachutes, and cables. The helium balloons provide lift for the powered parachutes, allowing them to ascend to a desired altitude. The powered parachutes capture wind energy at high altitudes and convert it into mechanical energy, which in turn drives ground-based generators to generate electricity. The cables connect the powered parachutes, helium balloons, and other aerial devices to ground-based devices. The aerial devices of land-based high-altitude wind power generation systems offer advantages such as light weight, low safety risks, and large-scale scalability. For example, several powered parachutes can be placed on a cable to form a parachute-ladder high-altitude wind power generation system.

[0063] Exemplarily, the ground device may include a universal wheel, a tensioning device, a winch, and a generator, among which the universal wheel is used to adapt to changes in wind direction at high altitudes, ensuring that the direction of the cable can be adjusted with changes in wind direction, thereby maximizing the capture of wind energy; the tensioning device is used to maintain the tension of the cable, ensuring that the cable is stable and effectively converts the wind force at high altitudes into mechanical energy; the winch is connected to the working parachute through a cable; the generator generates electrical energy under the drive of the winch, and can transmit and distribute the electrical energy through the transmission network.

[0064] The power generation principle of the land-based high-altitude wind power generation system is as follows: the generator is placed on the ground, and at the same time, like "flying and retracting a kite", the parachute moves up and down in a circular motion, so that the power generation can be achieved in the air and on the ground. Specifically, a helium balloon can be used to provide the initial lift for the parachute, which is opened after rising to a certain height. The parachute is tied to a cable and, under the action of wind, drives the cable to reciprocate and pull the ground generator turntable to rotate, converting mechanical energy into electrical energy to achieve power generation.

[0065] It should be noted that the structure of the above-mentioned land-based high-altitude wind power generation system is only an example and may include more or fewer devices, without limitation.

[0066] Among them, the working parachute, also known as a flexible parachute, is a flexible, highly deformable structure that needs to be dynamically opened and closed repeatedly during operation. Its movement in the wind is complex. Simulating its dynamic opening and closing process is a key step in the design and optimization of high-altitude wind power generation systems. Compared with traditional experimental methods, simulation has the advantages of high efficiency, short time consumption, resource conservation, no restrictions on experimental sites and data, and easy explanation of mechanical mechanisms. Currently, there is a lack of simulation solutions for the dynamic characteristics of working parachutes in parachute ladder-type high-altitude wind power development systems. The closest to the simulation of working parachutes is the research on parachutes, but parachutes generally open once and fall vertically, which is completely different from the dynamic process of the working parachute described in this disclosure. The typical simulation method for the most similar parachute is mainly based on the grid-based computational fluid dynamics method coupled with solid motion. For example, the CFD (Computational Fluid Dynamics) method is coupled with the MSD (Mass Spring Damper) model to complete the simulation of the dynamic behavior characteristics of the canopy structure during the parachute opening process, taking into account the deformation characteristics and energy dissipation of the canopy structure. For another example, the improved modeling technology based on the FSI (Fluid-Structure Interaction) method is used to describe the falling and gliding performance of a conceptual parachute design with geometric complexity. The core of this modeling method is to construct a deformable airspace / stable time-space domain to simulate the movable boundary and fluid-solid interface to characterize more complex fluid-solid coupling phenomena. At the same time, this method provides a more precise grid movement method, reduces the number of grid re-divisions, reduces the difficulty of describing geometrically complex canopies, and improves the convergence level of iterative solution results. For another example, the SSTFSI (Stabilized Space-Time Fluid-Structure Interaction) method is used to describe the falling and gliding performance of a conceptual parachute design with geometric complexity. The SSTFSI technology is an improvement on the grid-based fluid-structure interaction modeling method FSI, and is suitable for situations where the fluid and structural grids at the interface are incompatible. For another example, the ALE (Arbitrary Lagrangian Euler) method and grid adaptation technology are used to simulate the finite mass parachute opening process.

[0067] However, the above-mentioned research methods for parachutes are all based on flow field grid generation. Such methods have great limitations when dealing with large deformation problems, and will generate huge computational consumption in the motion state calculation of the parachute system.

[0068] The disclosed embodiments provide a method for simulating the dynamic opening and closing characteristics of a flexible umbrella structure with bidirectional fluid-solid coupling (described below in detail). This method is based on the lumped mass method-smoothed particle hydrodynamics (SPH) coupling to simulate an aerial working parachute in a land-based high-altitude wind power generation system. It can efficiently simulate the dynamic behavior of the working parachute in a highly dynamic and complex flow field.

[0069] Among them, the concentrated mass method replaces the continuous structure with discrete particles, and represents the corresponding properties of the original structure by describing the properties of the particle group (i.e., a mechanical system composed of many particles that interact with each other), such as displacement and acceleration; this method can be applied to simplify the dynamic simulation of complex continuous structures. The smooth particle fluid dynamics method is a gridless fluid dynamic analysis method, which avoids problems such as grid distortion that may occur in the calculation process of traditional grid models, and is not affected by the randomness of actual particle distribution, and the free boundary of the generated model will not have numerical divergence. Therefore, compared with traditional methods, the concentrated mass method-SPH coupling mode in the embodiment of the present disclosure is more suitable for simulating the situation where a flexible working umbrella violently moves and undergoes significant deformation in a highly dynamic and complex flow field.

[0070] The following is a detailed description of the work-performing parachute simulation method provided by the embodiment of the present disclosure.

[0071] Figure 2 A flow chart showing a method for simulating the dynamic opening and closing characteristics of a flexible umbrella structure with bidirectional fluid-solid coupling according to an embodiment of the present disclosure is shown. The method is applied to the dynamic simulation of a working umbrella in an umbrella ladder type high altitude wind power generation system. For example, Figure 1 For example, the method can be performed by a processing device with data processing capabilities, such as a computer, a processor, a server, etc. Figure 2 As shown, the method may include the following steps:

[0072] Step 201: Establish a work-doing parachute model and a flow field model around the work-doing parachute; wherein the work-doing parachute model is constructed based on a lumped mass method; and the flow field model is constructed based on a smoothed particle fluid dynamics method.

[0073] For example, before establishing a power parachute model, parameters such as the power parachute's components, dimensions, and shape can be pre-set as needed. For example, the power parachute's components may include a parachute body and parachute lines, where the parachute body may include parachute reinforcement ribs and a canopy. The power parachute's dimensions may include, for example, the diameter of the parachute head. The power parachute's shape may include square, circular, airfoil, bi-conical, striped, guide-surface, and rotary. It will be appreciated that during the power parachute's operation, its state will continuously change, and accordingly, its shape will also change. Furthermore, since the power parachute dynamically opens and closes repeatedly during operation, the parameters of the power parachute in its fully opened state can be used to simulate the parameters of the power parachute in its collapsed state through a natural descent process, based on the parameters of the power parachute in its fully opened state. Figure 3 A schematic structural diagram of a working umbrella in a folded state according to an embodiment of the present disclosure is shown.

[0074] Furthermore, a work-doing parachute model is constructed based on the lumped mass method. For example, the component units of the work-doing parachute model include multiple mass points. The number, density, distribution, and other conditions of the mass points included in the work-doing parachute model can be set according to needs and are not limited thereto. It can be understood that as the simulation proceeds, the state of the work-doing parachute will continue to change, and the speed and position of each mass point in the work-doing parachute model will also continue to change. For example, the initial speed of each mass point in the work-doing parachute model can be set to zero, and the initial position of each mass point in the work-doing parachute model can be the coordinates of each mass point in a preset coordinate system when the work-doing parachute is in a fully opened state.

[0075] In one possible implementation, establishing the work-doing umbrella model includes: using the lumped mass method to describe the work-doing umbrella to obtain the plurality of mass points; for any mass point among the plurality of mass points, determining a mechanical unit corresponding to the mass point, wherein the mechanical unit is used to connect the mass point to at least one other mass point among the plurality of mass points; the mechanical unit includes one or more of a bending spring, a shear spring, and a tension spring; and establishing the work-doing umbrella model based on the plurality of mass points and the mechanical units corresponding to each of the plurality of mass points. For example, the lumped mass method can be used to describe the work-doing umbrella in a fully opened state, thereby using the plurality of mass points to represent the work-doing umbrella and implementing Lagrangian particle modeling of the work-doing umbrella body; for each mass point, the mechanical unit corresponding to the mass point includes a bending spring, a shear spring, and a tension spring, and the mass point is connected to other different mass points via different springs, thereby establishing a mass-spring model, i.e., the work-doing umbrella model. Figure 4 FIG. 1 is a structural diagram showing a working parachute in a fully opened state according to an embodiment of the present disclosure. Figure 4As shown, the finite mass method (i.e., the lumped mass method) is used to describe the parachute body of the power-working parachute using mass points, and each mass point is a component unit of the power-working parachute model, wherein the bending spring, shear spring, and tension spring are the mechanical units corresponding to each mass point; in this way, based on the lumped mass method, the description of the parachute body reinforcement ribs and the canopy fabric of the power-working parachute is realized by combining different mechanical units such as bending springs, shear springs, and tension springs.

[0076] Furthermore, a flow field model around the working parachute can be established based on the smooth particle fluid dynamics method. For example, the component units of the flow field model include multiple fluid particles (also referred to as particles, SPH particles, and fluid particle elements); wherein the number, density, distribution, and other conditions of the fluid particles contained in the flow field model can be set according to needs, and there is no limitation on this; it can be understood that as the simulation proceeds, due to the interaction between the working parachute and the air, the position and velocity of the fluid particles in the flow field model will continue to change. For example, the initial velocity of the fluid particles in the flow field model can be the wind speed to be simulated, and the initial position of the fluid particles can be the coordinates of each fluid particle in a preset coordinate system.

[0077] In one possible implementation, establishing a flow field model around the work-making parachute includes: determining a target flow field based on the work-making parachute model, so that the work-making parachute model is immersed in the target flow field; using the smoothed particle fluid dynamics method to determine multiple fluid particles within the target flow field; and establishing the flow field model based on the multiple fluid particles. The shape, range, and boundary conditions of the target flow field can be set as needed, while ensuring that the work-making parachute model can be immersed in the target flow field. Furthermore, all fluid particles in the target flow field can be used as fluid particles in the flow field model around the work-making parachute, with each fluid particle carrying a portion of the mass of the fluid and having velocity, density, pressure, and viscosity properties, thereby establishing a flow field model around the work-making parachute within the target flow field. Taking into account that as the simulation progresses, the relative positions of the fluid particles in the flow field model and the particles in the work-doing umbrella model are constantly changing, the work-doing umbrella model may overflow the target flow field. Therefore, during the simulation process, the target flow field can be updated regularly. For example, some fluid particles that exceed the range can be deleted in the current flow field according to the latest positions of the particles in the work-doing umbrella model, and some new fluid particles can be added at the entrance position of the target flow field to maintain the macroscopic continuity of the fluid. The properties of the new fluid particles can be determined based on the properties or initial properties of the fluid particles in the previous time step, thereby ensuring that the work-doing umbrella model can always be immersed in the updated target flow field. Correspondingly, as the target flow field is updated, the fluid particles in the flow field model will also increase and decrease accordingly, thereby synchronously updating the flow field model. Figure 5 FIG. 1 shows a structural diagram of a bidirectional fluid-solid coupling system according to an embodiment of the present disclosure. Figure 5 As shown, the target flow field is a rectangular space, the inlet plane and the outlet plane of the target flow field are perpendicular to the movement direction of the power-working parachute, and the four side surfaces of the target flow field are parallel to the movement direction of the power-working parachute; illustratively, the average distance between the inlet plane of the target flow field and the canopy of the power-working parachute is not less than the canopy head diameter of the power-working parachute, the average distance between the outlet plane of the target flow field and the canopy of the power-working parachute is not less than five times the canopy head diameter of the power-working parachute, and the average distance between the side surface of the target flow field and the outer edge of the canopy of the power-working parachute is not less than the canopy head diameter of the power-working parachute, thereby ensuring that the power-working parachute model is immersed in the target flow field; wherein, the average distance between a certain plane of the target flow field (such as the inlet plane, the outlet plane, and the side surface) and the canopy of the power-working parachute can be the average value of the distance between each particle in the power-working parachute model and the plane of the target flow field.

[0078] Step 202: construct a bidirectional fluid-structure coupling system based on the work-doing umbrella model and the flow field model; wherein, in the bidirectional fluid-structure coupling system, there are interactions between some component units corresponding to the work-doing umbrella model and some component units corresponding to the flow field model.

[0079] Among them, bidirectional fluid-solid coupling refers to the interaction between fluid and solid structure; when the fluid flow contacts the solid structure, the fluid will exert pressure and viscous force on the solid structure, causing the structure to deform; at the same time, the deformation of the solid structure will in turn affect the flow pattern of the fluid. In the scenario of the dynamic simulation of the working umbrella in this embodiment, the fluid is air and the solid structure is the working umbrella. In this step 202, based on the above-established working umbrella model and flow field model, a bidirectional fluid-solid coupling system is constructed to achieve bidirectional fluid-solid coupling between the working umbrella and the fluid. For example, the above Figure 5 There is interaction between some fluid particles in the flow field model constructed in the target flow field and some particles of the work-making umbrella. These two models constitute a bidirectional fluid-solid coupling system.

[0080] It can be understood that as the simulation progresses, the state of the work umbrella changes continuously, the speed and position of the particles in the work umbrella model also change continuously, and the speed and position of the fluid particles in the flow field model also change continuously. At the same time, as the target flow field is updated, some fluid particles in the flow field model will also change; accordingly, the particles and fluid particles in the work umbrella model that interact with those in the flow field model will also change, that is, during the simulation process, the particles and fluid particles that interact with each other in the bidirectional fluid-solid coupling system will change.

[0081] Step 203 : Perform simulation based on the bidirectional fluid-structure coupling system to solve the dynamic information of the working umbrella model and the dynamic information of the flow field model corresponding to each time step to determine the characteristics of the working umbrella during the dynamic opening and closing process.

[0082] Here, a time step represents the division of the dynamic opening and closing process of the active parachute to be simulated into multiple consecutive time periods. Each time period is a time step, and the duration of the time period is the time step length. For example, the process of the active parachute from fully opened to fully collapsed can be divided into multiple time steps; another example is that a certain number of time steps can be pre-set; another example is that the process from the start of the simulation to the time the model enters a stable state can be divided into multiple time steps. The length of the time step is the time step, which can be set as needed. The time steps corresponding to different time steps can be the same or different. In one possible implementation method, the step size corresponding to each time step is determined by the fluid particle density in the target flow field. As the simulation progresses, the fluid particle density in the target flow field will continue to change, that is, the fluid particle density in the target flow field may be different at different stages of the simulation. The step size corresponding to the time step in the stage can be determined according to the fluid particle density in the target flow field at different stages, so that different time steps are used to solve the dynamic information of the work-doing parachute model and the dynamic information of the flow field model, thereby achieving a refined characterization of the dynamic changes of the parachute structure of the work-doing parachute.

[0083] For example, during the simulation process, as the time step continues to advance, the target flow field can be updated every preset number of time steps, so that the work-doing umbrella model is immersed in the target flow field through dynamic adjustment of the target flow field; wherein, during each update, the fluid particles to be deleted and added can be determined according to the position of each particle in the work-doing umbrella model in the current time step, thereby updating the target flow field, and accordingly, the above steps 201 and 202 are repeated to update the flow field model and the bidirectional fluid-solid coupling system based on the updated target flow field.

[0084] For example, dynamic information can include force, position, velocity, and acceleration. Accordingly, the dynamic information of a power-operating parachute model includes the force, velocity, and position of each particle in the parachute model; the dynamic information of a flow field model includes the force, velocity, and position of each fluid particle in the flow field model. When solving the dynamic information of the work-doing umbrella model and the dynamic information of the flow field model corresponding to each time step, a force analysis can be performed on each particle in the work-doing umbrella model, that is, each fluid particle in the flow field model, at each time step to achieve force coupling between different component units; furthermore, for any time step, a numerical integration method can be used to solve the acceleration of each particle in the work-doing umbrella model and the acceleration of each fluid particle in the flow field model based on the force analysis results; furthermore, the velocity and position of each particle in the work-doing umbrella model and the velocity and position of each fluid particle in the flow field model at the previous time step are combined to determine the velocity and position of each particle in the work-doing umbrella model and the velocity and position of each fluid particle in the flow field model at this time step; thereby achieving the coupled solution of fluid particles and particles in the bidirectional fluid-solid coupling system, and accurately updating the velocity and position of each particle in the work-doing umbrella model and the velocity and position of each fluid particle in the flow field model at each time step. Figure 6 A schematic diagram showing the simulation results of the dynamic change process of the parachute of a power-operated parachute according to an embodiment of the present disclosure is shown as follows: Figure 6 As shown, the states of the working parachute corresponding to five different time steps (i.e., t=0.0s, t=1.0s, t=2.0s, t=10.0s, and t=11.5s) are shown. At different time steps, the position and velocity of each particle in the working parachute model change.

[0085] In this step, the dynamic opening and closing process of the power parachute is simulated based on the bidirectional fluid-structure coupling system established above. During the simulation process, a multiple time stepping strategy is adopted to perform a coupled solution at each time step, thereby obtaining the dynamic information of the power parachute model and the dynamic information of the flow field model corresponding to each time step. Based on the dynamic information of the power parachute model corresponding to each time step, the dynamic behavior of the power parachute can be analyzed to determine the characteristics of the power parachute during the dynamic opening and closing process. In addition, the flow field changes around the power parachute can also be determined based on the dynamic information of the flow field model corresponding to each time step. Among them, the initial velocity of each fluid particle in the flow field model can be set as required to simulate different wind speed conditions and realize the simulation of the power parachute under different wind speed conditions. The force state of the power parachute during the opening and closing process under different wind speed conditions can be effectively given, thereby better assisting the design and operation optimization of land-based high-altitude wind power generation systems and promoting the development of new energy and other fields. Compared with traditional simulation methods, the dynamic behavior of the power parachute in a strong dynamic and complex wind field can be simulated with high accuracy in a shorter time.

[0086] In the disclosed embodiment, a work-operating parachute model and a flow field model around the work-operating parachute are established; wherein the work-operating parachute model is constructed based on the lumped mass method; the flow field model is constructed based on the smoothed particle fluid dynamics method; based on the work-operating parachute model and the flow field model, a bidirectional fluid-structure coupling system is constructed; wherein, in the bidirectional fluid-structure coupling system, there is interaction between the component units corresponding to the work-operating parachute model and the component units corresponding to the flow field model; based on the bidirectional fluid-structure coupling system, a simulation is performed to solve the dynamic information of the work-operating parachute model and the dynamic information of the flow field model corresponding to each time step to determine the characteristics of the work-operating parachute during the dynamic opening and closing process. This achieves the dynamic simulation of the work-operating parachute in the parachute ladder high-altitude wind power generation system. In this way, a power parachute model is constructed based on the lumped mass method, and a flow field model around the power parachute is constructed based on the smoothed particle fluid dynamics method, achieving Lagrangian particle modeling of both the parachute body and the surrounding fluid in the bidirectional fluid-solid coupling system. Furthermore, a multiple time-stepping strategy is employed to couple and solve the bidirectional fluid-solid coupling system, solving the dynamic information of the power parachute model and the dynamic information of the flow field model corresponding to each time step, thereby determining the characteristics of the power parachute during the dynamic opening and closing process. Compared to traditional simulation methods, the method in the disclosed embodiment can complete a highly accurate simulation of the dynamic behavior of the power parachute in a highly dynamic and complex wind field in a shorter time. Furthermore, the flow field changes around the power parachute can be obtained. This method can be applied to the analysis and prediction of power parachute operating conditions in actual engineering projects, thereby better assisting the design and operation optimization of land-based high-altitude wind power generation systems and promoting the development of new energy and other fields.

[0087] The specific process of solving the dynamic information of the work-doing parachute model and the dynamic information of the flow field model corresponding to each time step based on the multiple time-stepping strategy in step 203 is exemplarily described below.

[0088] Figure 7 A flow chart of a method for simulation based on a bidirectional fluid-solid coupling system according to an embodiment of the present disclosure is shown. The flow chart can be used as the above Figure 2 A possible implementation of step 203 is as follows: Figure 7 As shown, the following steps are included:

[0089] Step 701: At any time step, perform a penetration test between each fluid particle in the flow field model and each surface element in the work-doing umbrella model, and between different surface elements in the work-doing umbrella model.

[0090] Among them, any surface element (also called unit surface element or structural surface element) is composed of multiple particles in the work parachute model. Figure 4As shown in , a rectangular area composed of four mass points is a surface element. At any time step, the position of each surface element can be determined based on the positions of the multiple mass points that make up the surface element.

[0091] Exemplarily, at any time step, a penetration test is performed between each fluid particle in the flow field model and each surface element in the work-working umbrella model. This may include: for each fluid particle, detecting the position of the fluid particle in the previous time step, the estimated position of the fluid particle in the current time step, and the estimated position of the surface element in the work-working umbrella model closest to the fluid particle in the current time step, to determine whether there is a penetration depth between the fluid particle and the closest surface element in the work-working umbrella model. In other words, detecting whether the position of the fluid particle in the previous time step and the position of the fluid particle in the current time step are located on both sides of the estimated position of the closest surface element in the current time step. If they are located on both sides, it indicates that the fluid particle will penetrate the surface element to a certain depth after the time step; if they are located on the same side, it indicates that the fluid particle will still not penetrate the surface element after the time step. The estimated position of the fluid particle in the current time step can be determined based on the position, velocity, and acceleration of the fluid particle in the previous time step, and the estimated position of the surface element in the current time step can be determined based on the position, velocity, and acceleration of the particles constituting the surface element in the previous time step.

[0092] Illustratively, at any time step, performing penetration detection between different facets in the working parachute model may include: for any facet, detecting the facet's position at the previous time step, the facet's estimated position at the current time step, and the estimated positions of the facets closest to the facet in the working parachute model at the current time step, to determine whether there is a penetration depth between the facet and the facet. Specifically, detecting whether the facet's position at the previous time step and the facet's position at the current time step are located on either side of the estimated position of the facet at the current time step. If so, this indicates that the facet will penetrate the facet to a certain depth after the time step. If so, this indicates that the facet will not penetrate the facet after the time step.

[0093] Step 702: Based on the mold penetration detection result, determine the fluid particles and particles that interact with each other, and the different particles that interact with each other in the bidirectional fluid-solid coupling system.

[0094] As the simulation progresses, the interacting fluid particles and particles, as well as the different interacting particles, in the bidirectional fluid-solid coupling system may change. In step 702, at any time step, the interacting fluid particles and particles, as well as the different interacting particles, in the bidirectional fluid-solid coupling system are determined based on the penetration detection result of the current time step.

[0095] The mold penetration detection results include whether there is a penetration depth or not. Through the above step 701, each fluid particle in the flow field model is traversed, and for each fluid particle, a check is made to see whether there is a penetration depth between it and the nearest surface element in the work-making umbrella model. If so, the fluid particle and the particles constituting the surface element are determined to be fluid particles and particles that interact with each other in the bidirectional fluid-solid coupling system. Correspondingly, each surface element in the work-making umbrella model is traversed, and for each surface element, a check is made to see whether there is a penetration depth between it and the nearest other surface elements in the work-making umbrella model. If so, the particles constituting the surface element and the particles constituting the other surface elements are determined to be different particles that interact with each other in the bidirectional fluid-solid coupling system.

[0096] Step 703: Calculate the force between the interacting fluid particles and the mass points, and the force between the interacting different mass points, using a penalty function.

[0097] For example, at any time step, the force between the interacting fluid particles and the mass points in the bidirectional fluid-solid coupling system is calculated by the penalty function, and then the force can be introduced as a penalty force term, i.e., an external force term, when performing force analysis on the interacting fluid particles and the mass points.

[0098] For example, at any time step, the force between different interacting particles in a bidirectional fluid-solid coupling system is calculated using a penalty function, and then this force can be introduced as a penalty force term, i.e., an external force term, when performing force analysis on different interacting particles.

[0099] Among them, the penalty function Generally has the following form:

[0100]

[0101] Where: k penalty is the penalty coefficient, which is also the stiffness coefficient of the work parachute element. The value of this coefficient can be set as required. l is the penetration depth of the fluid particles on the element or the penetration depth of one element on another element. The penetration depth can be determined based on the positions of the two elements. is the outward normal unit vector of the penetrated surface element.

[0102] In this way, through the above steps 701-703, at any time step, the mode penetration detection combined with the penalty function is used to realize the modeling of the interaction contact force between the two. Specifically, the fluid-solid coupling calculation of the fluid and the work-making parachute (i.e., the mode penetration detection of the fluid particles and the work-making parachute surface elements and the force between the fluid particles and the particles) and the self-contact analysis of the work-making parachute canopy (i.e., the mode penetration detection between different surface elements of the work-making parachute and the force between the particles constituting different surface elements) are both performed in this way.

[0103] Step 704: Determine the dynamic information of the flow field model corresponding to the time step based on the interaction forces between the interacting fluid particles and the mass points and the interaction forces between the fluid particles in the flow field model.

[0104] In this step, a force analysis is performed on each fluid particle in the bidirectional fluid-solid coupling system at any time step. For any fluid particle, if there is a penetration depth between the fluid particle and the surface element, that is, the above step calculates the force between the fluid particle and the particle through the penalty function, then the force is used as an external force term, and the surface force and volume force of the fluid particle are calculated, which includes the force between the fluid particle and other fluid particles, thereby completing the force analysis of the fluid particle; for any fluid particle, if there is no penetration depth between the fluid particle and the surface element, that is, the above step does not calculate the force between the fluid particle and the particle through the penalty function, then the surface force and volume force of the fluid particle are calculated, that is, the force between the fluid particle and other fluid particles, thereby completing the force analysis of the fluid particle. Furthermore, after completing the force analysis of each fluid particle in the flow field model, a numerical integration is performed to determine the dynamic information of the flow field model corresponding to the time step, that is, the position and velocity of each fluid particle in the flow field model at the time step can be determined. For example, the Velocity-Verlet integral can be used to calculate Newton's second law, and the position and velocity of each fluid particle in the flow field model can be updated at each time step; the basic idea of ​​the Velocity-Verlet method is to approximate the motion of particles through Taylor series expansion.

[0105] In one possible implementation, determining the dynamic information of the flow field model corresponding to the time step based on the interaction forces between the interacting fluid particles and the mass points and the interaction forces between the fluid particles in the flow field model includes: performing a neighborhood search for each fluid particle in the flow field model and updating the density attribute of the fluid particle based on the neighborhood search result; updating the pressure attribute of the fluid particle based on the density attribute of the fluid particle; determining the interaction forces between the fluid particle and other fluid particles based on the current velocity of the fluid particle, the density attribute, the pressure attribute, and the viscosity attribute; and determining the dynamic information of the fluid particle corresponding to the time step based on the interaction forces between the fluid particle and other fluid particles and the interaction forces between the fluid particle and the mass points in the work-doing umbrella model. Exemplarily, performing a neighborhood search for each fluid particle in the flow field model to search for other fluid particles within its neighborhood, the neighborhood search result being the other fluid particle, and then updating the density attribute of the fluid particle; exemplarily, the pressure attribute of the fluid particle can be updated based on the density attribute of the fluid particle and the distribution of other fluid particles in its neighborhood.

[0106] As an example, at any time step, for each fluid particle (unit mass) in the flow field model, the force equation of the fluid particle can be expressed as:

[0107]

[0108] Where: is the acceleration of the fluid particles; is the external force term of the fluid particle's acceleration, that is, the acceleration term generated by the gravitational acceleration of the fluid particle and the force between the fluid particle and the particle calculated by the penalty function; p is the pressure of the fluid particle, that is, the pressure property of the fluid particle; ρ is the equivalent density of the fluid particle, that is, the density property of the fluid particle; μ is the viscosity coefficient of the fluid, that is, the viscosity property of the fluid particle; is the current velocity of the fluid particles. The pressure term that constitutes the acceleration, The viscous term that constitutes the acceleration, and both are the surface forces on the fluid particles.

[0109] The position of the fluid particle can be expressed as:

[0110]

[0111] Among them, v n ″ represents the velocity of the fluid particle at the nth time step, x′ n ′ represents the position of the fluid particle at the nth time step, x′ n ' +1 represents the position of the fluid particle at the n+1th time step, and Δt represents a time step.

[0112] The velocity of the fluid particles can be expressed as:

[0113]

[0114] Among them, v n ″ represents the velocity of the fluid particle at the nth time step, a′ n ′ represents the acceleration of the fluid particle at the nth time step, a′ n ' +1 represents the acceleration of the fluid particle at the n+1th time step, v′ n ' +1 represents the velocity of the fluid particle at the n+1th time step, and Δt represents a time step.

[0115] Step 705: Determine the dynamic information of the working umbrella model corresponding to the time step based on the forces between the interacting fluid particles and the mass points, the forces between the interacting different mass points, and the forces of the mechanical units corresponding to the mass points in the working umbrella model.

[0116] In this step, a force analysis is performed on each particle in the bidirectional fluid-solid coupling system at any time step. For any particle, if there is a penetration depth between the surface element where the particle is located and other surface elements, that is, the above step calculates the force between the particle and the particles of the other surface elements through the penalty function, then this force is used as an external force term; if there is a penetration depth between the fluid particles and the surface element where the particle is located, that is, the above step calculates the force between the fluid particles and the particle through the penalty function, then this force is used as an external force term; if the particle has both of the above two penetration depths, then the force between the particle and the particles of the other surface elements and the force between the fluid particles and the particle are used as external force terms; if neither of the above two penetration depths exists, the external force term is zero. Based on the determination of the external force term, the force of the mechanical unit corresponding to the particle is calculated, thereby completing the force analysis of the particle. After completing the force analysis of each particle in the work-doing parachute model, numerical integration is performed to determine the dynamic information of the work-doing parachute model corresponding to that time step, i.e., the position and velocity of each particle in the work-doing parachute model at that time step. For example, Velocity-Verlet integration can be used to calculate Newton's second law, updating the position and velocity of each particle in the work-doing parachute model at each time step.

[0117] Figure 8 Schematic diagram showing a working umbrella in a closed and open state according to an embodiment of the present disclosure, as shown in FIG. Figure 8 As shown in the figure, under the influence of wind speed, the power parachute gradually changes from a closed state to an open state. As the shape of the power parachute changes, the force and dynamic information of the same particle in the power parachute change.

[0118] In one possible implementation, determining the dynamic information of the work-doing umbrella model corresponding to the time step based on the forces between the interacting fluid particles and the mass points, the forces between the different interacting mass points, and the forces of the mechanical units corresponding to each mass point in the work-doing umbrella model may include: determining, for each mass point in the work-doing umbrella model, the forces of the mechanical units corresponding to the mass point based on the forces of the tension spring, the shear spring, and the bending spring borne by the mass point; determining the forces between the mass point and the fluid particles in the flow field model, and the forces between the mass point and the mass points in the work-doing umbrella model; and determining the dynamic information of the mass point corresponding to the time step based on the forces of the mechanical units corresponding to the mass point, the forces between the mass point and the fluid particles in the flow field model, and the forces between the mass point and the mass points in the work-doing umbrella model. Exemplarily, the force exerted by the tensile spring on the mass point, the force exerted by the shear spring on the mass point, and the force exerted by the bending spring on the mass point are calculated using Hooke's law based on the positions of other mass points connected to the mass point on the corresponding spring and the position of the mass point.

[0119] As an example, at any time step, for each mass point (unit volume) in the work parachute model, the force equation of the mass point can be expressed as:

[0120]

[0121] Where: ρ m is the equivalent density of the particle; is the acceleration of the particle; is the external force term borne by the particle, namely the gravity of the particle and the force between the particle and the fluid particles calculated by the penalty function, as well as the force between the particle and the particles on other surface elements; is the tensile spring force borne by the mass point; is the shear spring force borne by the mass point; is the bending spring force borne by the mass point.

[0122] The position of the particle can be expressed as:

[0123]

[0124] Among them, v n ′ represents the velocity of the particle at the nth time step, x′ n represents the position of the particle at the nth time step, x′ n+1 represents the position of the particle at the n+1th time step, and Δt represents a time step.

[0125] The velocity of the particle can be expressed as:

[0126]

[0127] Among them, v n ′ represents the velocity of the particle at the nth time step, a′ n represents the acceleration of the particle at the nth time step, a′ n+1 represents the acceleration of the particle at the n+1th time step, v′ n+1 represents the velocity of the particle at the n+1th time step, and Δt represents a time step.

[0128] For example, Figure 9 A flow chart of a simulation according to an embodiment of the present disclosure is shown as follows: Figure 9 As shown, a flexible structure model (i.e., a work-making umbrella model) is established through step 1.1, and a flow field model (i.e., a flow field model around the work-making umbrella) is established through step 1.2 (i.e., the aforementioned step 201). The flexible structure model is established using the lumped mass method, the fluid particle microelement model is established using the SPH method, and the range and boundary conditions of the target flow field are set. Furthermore, the fluid-solid model is adapted and coupled through step 2. Specifically, a penalty function method can be used as a force coupling method, a Velocity-Verlet method can be used as a numerical integration method, and the fluid state in the flow field and the structural particle information are updated. The penalty function method specifically includes: performing neighborhood retrieval on each fluid particle, updating the density properties of the fluid particles, updating the pressure properties of the fluid particles based on the density properties of the fluid particles, performing penetration detection between each fluid particle and the flexible structure, applying penetration penalties, and updating the forces on the fluid particles and the structural particles. Then, in step 3, a dynamic simulation of the power-producing parachute structure under the action of air load is performed. During the simulation process, the above steps are repeated until the simulation is completed, thereby obtaining the fluid state in the flow field at different time steps and the particle information in the flexible structure model (i.e., the above steps 202 and 203) to analyze the dynamic behavior of the power-producing parachute.

[0129] Based on the same inventive concept of the above method embodiment, an embodiment of the present disclosure also provides a device for simulating the dynamic opening and closing characteristics of a flexible umbrella structure with bidirectional fluid-solid coupling, which can be used to implement the technical solution described in the above method embodiment.

[0130] Figure 10 The structure diagram of a dynamic opening and closing characteristic simulation device of a flexible umbrella structure with bidirectional fluid-solid coupling according to an embodiment of the present disclosure is shown, which is applied to the dynamic simulation of a working umbrella in an umbrella ladder type high altitude wind power generation system. Figure 10As shown, the device includes: a modeling module 1001, which is used to establish a work-doing umbrella model and a flow field model around the work-doing umbrella; wherein the work-doing umbrella model is constructed based on the lumped mass method; the flow field model is constructed based on the smoothed particle fluid dynamics method; the modeling module 1001 is also used to construct a two-way fluid-solid coupling system based on the work-doing umbrella model and the flow field model; wherein, in the two-way fluid-solid coupling system, there is interaction between some component units corresponding to the work-doing umbrella model and some component units corresponding to the flow field model; a simulation module 1002 is used to perform simulation based on the two-way fluid-solid coupling system to solve the dynamic information of the work-doing umbrella model and the dynamic information of the flow field model corresponding to each time step, so as to determine the characteristics of the work-doing umbrella during the dynamic opening and closing process.

[0131] In the disclosed embodiment, a work-operating parachute model and a flow field model around the work-operating parachute are established; wherein the work-operating parachute model is constructed based on the lumped mass method; the flow field model is constructed based on the smoothed particle fluid dynamics method; based on the work-operating parachute model and the flow field model, a bidirectional fluid-structure coupling system is constructed; wherein, in the bidirectional fluid-structure coupling system, there is interaction between the component units corresponding to the work-operating parachute model and the component units corresponding to the flow field model; based on the bidirectional fluid-structure coupling system, a simulation is performed to solve the dynamic information of the work-operating parachute model and the dynamic information of the flow field model corresponding to each time step to determine the characteristics of the work-operating parachute during the dynamic opening and closing process. This achieves the dynamic simulation of the work-operating parachute in the parachute ladder high-altitude wind power generation system. In this way, a power parachute model is constructed based on the lumped mass method, and a flow field model around the power parachute is constructed based on the smoothed particle fluid dynamics method, achieving Lagrangian particle modeling of both the parachute body and the surrounding fluid in the bidirectional fluid-solid coupling system. Furthermore, a multiple time-stepping strategy is employed to couple and solve the bidirectional fluid-solid coupling system, solving the dynamic information of the power parachute model and the dynamic information of the flow field model corresponding to each time step, thereby determining the characteristics of the power parachute during the dynamic opening and closing process. Compared to traditional simulation methods, the method in the disclosed embodiment can complete a highly accurate simulation of the dynamic behavior of the power parachute in a highly dynamic and complex wind field in a shorter time. Furthermore, the flow field changes around the power parachute can be obtained. This method can be applied to the analysis and prediction of power parachute operating conditions in actual engineering projects, thereby better assisting the design and operation optimization of land-based high-altitude wind power generation systems and promoting the development of new energy and other fields.

[0132] In one possible implementation, the constituent units of the work-doing parachute model include a plurality of mass points; the modeling module 1001 is further configured to: describe the work-doing parachute using the lumped mass method to obtain the plurality of mass points; determine, for any one of the plurality of mass points, a mechanical unit corresponding to the mass point, wherein the mechanical unit is configured to connect the mass point to at least one other mass point among the plurality of mass points; the mechanical unit includes one or more of a bending spring, a shear spring, and a tension spring; and establish the work-doing parachute model based on the plurality of mass points and the mechanical units corresponding to each of the plurality of mass points.

[0133] In one possible implementation, the component units of the flow field model include multiple fluid particles; the modeling module 1001 is further used to: determine a target flow field based on the work-doing umbrella model, so that the work-doing umbrella model is immersed in the target flow field; use the smoothed particle fluid dynamics method to determine multiple fluid particles in the target flow field; and establish the flow field model based on the multiple fluid particles.

[0134] In one possible implementation, the simulation module 1002 is further configured to: perform, at any time step, a mold penetration test between each fluid particle in the flow field model and each surface element in the work-doing umbrella model, and between different surface elements in the work-doing umbrella model, wherein any surface element is composed of multiple particles in the work-doing umbrella model; determine, based on the mold penetration test results, the interacting fluid particles and particles, as well as the interacting different particles in the bidirectional fluid-solid coupling system; calculate, using a penalty function, the forces between the interacting fluid particles and particles, and the forces between the interacting different particles; determine the dynamic information of the flow field model corresponding to the time step based on the forces between the interacting fluid particles and particles and the forces between the fluid particles in the flow field model; and determine the dynamic information of the work-doing umbrella model corresponding to the time step based on the forces between the interacting fluid particles and particles, the forces between the interacting different particles, and the forces of the mechanical units corresponding to the particles in the work-doing umbrella model.

[0135] In one possible implementation, the simulation module 1002 is further used to: perform a neighborhood search for each fluid particle in the flow field model, and update the density attribute of the fluid particle based on the neighborhood search result; update the pressure attribute of the fluid particle based on the density attribute of the fluid particle; determine the force between the fluid particle and other fluid particles based on the current velocity of the fluid particle, the density attribute, the pressure attribute, and the viscosity attribute; determine the dynamic information of the fluid particle corresponding to the time step based on the force between the fluid particle and other fluid particles and the force between the fluid particle and the particle in the work-doing umbrella model.

[0136] In one possible implementation, the simulation module 1002 is further configured to: determine, for each mass point in the work-doing parachute model, the force of the mechanical unit corresponding to the mass point based on the force of the tension spring, the force of the shear spring, and the force of the bending spring borne by the mass point; determine the force between the mass point and the fluid particles in the flow field model, and the force between the mass point and the mass points in the work-doing parachute model; and determine the dynamic information of the mass point corresponding to the time step based on the force of the mechanical unit corresponding to the mass point, the force between the mass point and the fluid particles in the flow field model, and the force between the mass point and the mass points in the work-doing parachute model.

[0137] In a possible implementation, the step size corresponding to each time step is determined by the density of fluid particles in the target flow field.

[0138] In some embodiments, the functions or modules included in the device provided by the embodiments of the present disclosure can be used to execute the method described in the above method embodiments. The specific implementation can refer to the description of the above method embodiments. For the sake of brevity, it will not be repeated here.

[0139] The present disclosure also provides a computer-readable storage medium having computer program instructions stored thereon, wherein the computer program instructions implement the above method when executed by a processor. The computer-readable storage medium may be a volatile or non-volatile computer-readable storage medium.

[0140] An embodiment of the present disclosure further proposes an electronic device, comprising: a processor; and a memory for storing instructions executable by the processor; wherein the processor is configured to implement the above method when executing the instructions stored in the memory.

[0141] An embodiment of the present disclosure also provides a computer program product, including computer-readable code, or a non-volatile computer-readable storage medium carrying computer-readable code. When the computer-readable code runs in a processor of an electronic device, the processor in the electronic device executes the above method.

[0142] Figure 11 FIG1 shows a block diagram of an electronic device 1900 according to an embodiment of the present disclosure. For example, the electronic device 1900 can be provided as a server or a terminal device. Figure 11 The electronic device 1900 includes a processing component 1922, which further includes one or more processors, and a memory resource represented by a memory 1932 for storing instructions executable by the processing component 1922, such as an application. The application stored in the memory 1932 may include one or more modules, each corresponding to a set of instructions. In addition, the processing component 1922 is configured to execute the instructions to perform the above-described method.

[0143] The electronic device 1900 may further include a power supply component 1926 configured to perform power management of the electronic device 1900, a wired or wireless network interface 1950 configured to connect the electronic device 1900 to a network, and an input / output interface 1958 (I / O interface). The electronic device 1900 may operate based on an operating system stored in the memory 1932, such as Windows Server 2003. TM , Mac OS X TM , Unix TM ,Linux TM , FreeBSD TM or similar.

[0144] In an exemplary embodiment, a non-volatile computer-readable storage medium is also provided, such as a memory 1932 including computer program instructions that can be executed by the processing component 1922 of the electronic device 1900 to perform the above method.

[0145] The present disclosure may be a system, method and / or computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present disclosure.

[0146] A computer-readable storage medium can be a tangible device that can hold and store instructions for use by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disc read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination thereof. As used herein, a computer-readable storage medium is not to be construed as a transient signal per se, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through an electrical wire.

[0147] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, fiber optic transmission, wireless transmission, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions to be stored in the computer-readable storage medium in each computing / processing device.

[0148] The computer program instructions for performing the operations of the present disclosure may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk, C++, and conventional procedural programming languages ​​such as "C" language or similar programming languages. Computer-readable program instructions may be executed entirely on a user's computer, partially on a user's computer, as an independent software package, partially on a user's computer, partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., utilizing an Internet service provider to connect via the Internet). In some embodiments, an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), may be personalized by utilizing the state information of the computer-readable program instructions. The electronic circuit may execute the computer-readable program instructions, thereby realizing various aspects of the present disclosure.

[0149] Various aspects of the present disclosure are described herein with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the present disclosure. It should be understood that each block of the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer-readable program instructions.

[0150] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine, so that when these instructions are executed by the processor of the computer or other programmable data processing device, a device is generated that implements the functions / actions specified in one or more blocks in the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium, where these instructions cause the computer, programmable data processing device, and / or other device to operate in a specific manner. Thus, the computer-readable medium storing the instructions comprises an article of manufacture that includes instructions for implementing various aspects of the functions / actions specified in one or more blocks in the flowchart and / or block diagram.

[0151] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device so that a series of operational steps are performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to implement the functions / actions specified in one or more blocks in the flowchart and / or block diagram.

[0152] The flow charts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems, methods and computer program products according to multiple embodiments of the present disclosure. In this regard, each box in the flow chart or block diagram can represent a part of a module, program segment or instruction, and the part of the module, program segment or instruction contains one or more executable instructions for realizing the prescribed logical function. In some alternative implementations, the functions marked in the box can also occur in a sequence different from that marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented by a dedicated hardware-based system that performs the prescribed function or action, or can be implemented by a combination of dedicated hardware and computer instructions.

[0153] While various embodiments of the present disclosure have been described above, the foregoing description is intended to be illustrative, non-exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is selected to best explain the principles of the embodiments, their practical applications, or technological improvements in the marketplace, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for simulating the dynamic opening and closing characteristics of a flexible umbrella structure with bidirectional fluid-solid coupling, which is applied to the dynamic simulation of the working umbrella in an umbrella ladder high-altitude wind power generation system, is characterized by: The method comprises: Establishing a work-doing parachute model and a flow field model around the work-doing parachute; wherein the work-doing parachute model is constructed based on the lumped mass method; and the flow field model is constructed based on the smoothed particle fluid dynamics method; Based on the work-doing umbrella model and the flow field model, a bidirectional fluid-solid coupling system is constructed; wherein, in the bidirectional fluid-solid coupling system, there is interaction between some component units corresponding to the work-doing umbrella model and some component units corresponding to the flow field model; Performing simulation based on the bidirectional fluid-structure coupling system to solve the dynamic information of the working umbrella model and the dynamic information of the flow field model corresponding to each time step to determine the characteristics of the working umbrella during the dynamic opening and closing process; The simulation based on the bidirectional fluid-solid coupling system is performed to solve the dynamic information of the work-doing parachute model and the dynamic information of the flow field model corresponding to each time step, including: At any time step, performing penetration detection between each fluid particle in the flow field model and each surface element in the work-doing umbrella model, and between different surface elements in the work-doing umbrella model, wherein any surface element is composed of multiple particles in the work-doing umbrella model; Based on the mold penetration detection results, determining the fluid particles and particles that interact with each other in the bidirectional fluid-solid coupling system, as well as the different particles that interact with each other; Calculating the force between the interacting fluid particles and the mass points, and the force between the interacting different mass points, by using a penalty function; Determining the dynamic information of the flow field model corresponding to the time step based on the interaction forces between the interacting fluid particles and the mass points and the interaction forces between the fluid particles in the flow field model; Based on the forces between the interacting fluid particles and the mass points, the forces between the interacting different mass points, and the forces of the mechanical units corresponding to the mass points in the work-doing umbrella model, the dynamic information of the work-doing umbrella model corresponding to the time step is determined.

2. The method according to claim 1, characterized in that The component units of the work-doing parachute model include a plurality of mass points; The method of establishing a work-performing umbrella model comprises: The work-doing parachute is described using the lumped mass method to obtain the plurality of mass points; For any mass point among the plurality of mass points, determining a mechanical unit corresponding to the mass point, wherein the mechanical unit is used to connect the mass point to at least one other mass point among the plurality of mass points; the mechanical unit includes one or more of a bending spring, a shear spring, and a tension spring; The work-doing parachute model is established based on the multiple mass points and the mechanical units corresponding to each of the multiple mass points.

3. The method according to claim 2, characterized in that The component units of the flow field model include a plurality of fluid particles; The step of establishing a flow field model around the working parachute comprises: determining a target flow field based on the work-doing parachute model, so that the work-doing parachute model is immersed in the target flow field; Using the smoothed particle hydrodynamics method, determining a plurality of fluid particles within the target flow field; The flow field model is established based on the multiple fluid particles.

4. The method according to claim 1, wherein The determining of the dynamic information of the flow field model corresponding to the time step based on the interaction forces between the interacting fluid particles and the mass points and the interaction forces between the fluid particles in the flow field model includes: Performing a neighborhood search for each fluid particle in the flow field model, and updating a density attribute of the fluid particle according to the neighborhood search result; Update the pressure attribute of the fluid particle according to the density attribute of the fluid particle; Determining the force between the fluid particle and other fluid particles based on the current velocity of the fluid particle, the density attribute, the pressure attribute, and the viscosity attribute; Based on the interaction force between the fluid particle and other fluid particles and the interaction force between the fluid particle and the mass point in the work-doing umbrella model, the dynamic information of the fluid particle corresponding to the time step is determined.

5. The method according to claim 1, wherein The determining of the dynamic information of the work-doing umbrella model corresponding to the time step based on the force between the interacting fluid particles and the mass points, the force between the interacting different mass points, and the force of the mechanical unit corresponding to each mass point in the work-doing umbrella model includes: For each mass point in the work-doing parachute model, determine the force of the mechanical unit corresponding to the mass point based on the force of the tension spring, the force of the shear spring, and the force of the bending spring borne by the mass point; Determining the force between the particle and the fluid particles in the flow field model, and the force between the particle and the particle in the work-doing umbrella model; Based on the force of the mechanical unit corresponding to the particle, the force between the particle and the fluid particles in the flow field model, and the force between the particle and the particles in the work umbrella model, the dynamic information of the particle corresponding to the time step is determined.

6. The method according to claim 3, characterized in that The step size corresponding to each time step is determined by the density of fluid particles in the target flow field.

7. A dynamic opening and closing characteristic simulation device for a flexible umbrella structure with bidirectional fluid-solid coupling, which is applied to the dynamic simulation of the working umbrella in the umbrella ladder high-altitude wind power generation system, characterized in that: The device comprises: A modeling module, for establishing a work-doing parachute model and a flow field model around the work-doing parachute; wherein the work-doing parachute model is constructed based on the lumped mass method; and the flow field model is constructed based on the smoothed particle hydrodynamics method; The modeling module is further configured to construct a bidirectional fluid-solid coupling system based on the work-doing umbrella model and the flow field model; wherein, in the bidirectional fluid-solid coupling system, there is interaction between some component units corresponding to the work-doing umbrella model and some component units corresponding to the flow field model; a simulation module, configured to perform simulation based on the bidirectional fluid-structure coupling system to solve the dynamic information of the working umbrella model and the dynamic information of the flow field model corresponding to each time step, so as to determine the characteristics of the working umbrella during the dynamic opening and closing process; The simulation module is configured to perform, at any time step, a mold penetration detection between each fluid particle in the flow field model and each surface element in the work-doing umbrella model, as well as between different surface elements in the work-doing umbrella model, wherein any surface element is composed of multiple particles in the work-doing umbrella model; determine, based on the mold penetration detection results, the interacting fluid particles and particles, as well as the different interacting particles in the bidirectional fluid-solid coupling system; calculate the forces between the interacting fluid particles and particles, and the forces between the different interacting particles, using a penalty function; determine the dynamic information of the flow field model corresponding to the time step based on the forces between the interacting fluid particles and particles and the forces between the fluid particles in the flow field model; and determine the dynamic information of the work-doing umbrella model corresponding to the time step based on the forces between the interacting fluid particles and particles, the forces between the different interacting particles, and the forces of the mechanical units corresponding to the particles in the work-doing umbrella model.

8. An electronic device, characterized in that: include: processor; a memory for storing processor-executable instructions; The processor is configured to implement the method according to any one of claims 1 to 6 when executing the instructions stored in the memory.

9. A non-volatile computer-readable storage medium having computer program instructions stored thereon, characterized in that: When the computer program instructions are executed by a processor, the method according to any one of claims 1 to 6 is implemented.

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