A computational method for pollutant tracking particle flow along the coast in complex coastline environments

Abstract

The present invention discloses a method for calculating the coastal flow of pollutant tracking particles in a complex shoreline environment. First, based on the hazardous chemical leakage model of the Lagrangian particle tracing algorithm, the present invention introduces the spatial judgment of the particle trajectory vector and the shoreline segment vector; secondly, based on the particle prediction vector trajectory and the shoreline segment vector, the vector offset of the particle after colliding with the shoreline is calculated; then, based on the vector offset after the particle collides with the shoreline, the spatial judgment of the particle trajectory and the shoreline segment vector is continued to be judged, and the vector offset of the particle trajectory is continuously calculated until the particle no longer collides with the shoreline; finally, the final offset position of the particle after colliding with the shoreline is transmitted back to the hazardous chemical leakage model, and the model continues the simulation prediction at the next time. The present invention realizes the drift and diffusion of dissolved or low-viscosity pollutant particles along the shoreline in a complex shoreline environment, which can avoid the hazardous chemical leakage model from predicting false local high-concentration pollution clusters in a complex shoreline environment.

Description

Technical Field

[0001] The present invention relates to the field of technical simulation technology, and in particular to a method for calculating the coastal flow of pollutant tracking particles in a complex coastline environment. Background Art

[0002] Due to the high incidence of hazardous chemical leaks and the volatile surface water environment and meteorological conditions surrounding the incidents, traditional monitoring methods cannot quickly and comprehensively grasp the current situation and future development trends of hazardous chemical pollution accidents. Therefore, rapid and accurate prediction and deduction of the spread of hazardous chemical leaks in sudden water pollution incidents can provide timely and effective guidance for the command and decision-making of accident emergency management departments.

[0003] Currently, well-known hazardous chemical leak models, both domestically and internationally, have gradually evolved from Eulerian-based numerical water quality models to gridless Lagrangian particle tracing algorithms. Because Eulerian-based water quality models can take hours to compute, it's difficult to quickly generate reliable predictions of pollutant drift and diffusion for emergency management decision-making. The Lagrangian particle tracing algorithm, on the other hand, treats water pollutants as a collection of a certain number of particles. By directly importing flow and wind field forecasts for the incident area into the model, the pollutant particles' next drift and diffusion locations are predicted based on surrounding flow and wind speed data, supplemented by a fixed shoreline to determine their landing status. This simulation algorithm is computationally lightweight and fast, requiring only minutes to calculate, effectively improving emergency response capabilities in water pollution emergencies.

[0004] However, existing hazardous chemical leak models based on the Lagrangian particle tracking algorithm have significant shortcomings in practical applications in nearshore and inland waters. Compared to the open ocean, the shoreline environment in nearshore and inland waters is extremely complex, and the spatial accuracy of the flow field data referenced by the model is often lower than the spatial resolution of the shoreline. This can cause soluble or low-viscosity pollutant particles to be trapped by the complex shoreline during drift and diffusion calculations (in reality, these particles should continue to drift around the shoreline), resulting in false predictions of localized high pollutant concentrations. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the present invention provides a method for calculating the coastal flow of pollutant tracking particles in a complex coastline environment.

[0006] In a first aspect, the present invention provides a method for calculating the coastal flow of pollutant tracking particles in a complex coastline environment, the method comprising the following steps:

[0007] Step 1. Based on the hazardous chemical leakage model of the Lagrangian particle tracing algorithm, a spatial judgment between the particle trajectory vector and the shoreline segment vector is introduced to determine whether the particle trajectory vector intersects with the shoreline segment vector. If so, the intersection point and the intersecting shoreline segment vector are determined;

[0008] Step 2. Based on the particle prediction vector trajectory and the shoreline segment vector, the vector offset after the particle hits the shoreline is calculated, and the trajectory deflection point after the particle hits the shoreline is determined;

[0009] Step 3. Based on the vector offset after the particle collides with the shoreline, continue to determine the spatial relationship between the particle trajectory and the shoreline segment vector, and continue to calculate the vector offset after the particle trajectory collides with the shoreline until the particle no longer collides with the shoreline;

[0010] Step 4. The final offset position of the particle after colliding with the shoreline is transmitted back to the hazardous chemical leakage model. The hazardous chemical leakage model uses the final offset position as the starting position of the particle at the next moment and continues the simulation prediction.

[0011] In a second aspect, the present invention provides a pollutant tracking particle alongshore flow calculation device, comprising:

[0012] memory for storing computer programs;

[0013] The processor is used to call and execute the computer program to implement the various steps of the pollutant tracking particle alongshore flow calculation method as described above.

[0014] In a third aspect, the present invention provides a storage medium having a computer program stored thereon, which, when executed by a processor, implements the various steps of the pollutant tracking particle alongshore flow calculation method.

[0015] The beneficial effects of the present invention are: the present invention designs a particle coastal flow algorithm, which realizes the coastal flow drift and diffusion of dissolved or low-viscosity pollutant particles in a complex shoreline environment, and can avoid the hazardous chemical leakage model from predicting false local high-concentration pollution clusters. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a flow chart of the method of the present invention;

[0017] Figure 2 This is an example diagram of the particle flow algorithm of the present invention for predicting the particle vector trajectory after colliding with the shoreline. DETAILED DESCRIPTION

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. The exemplary embodiments and descriptions of the present invention are used to explain the present invention but are not intended to limit the present invention.

[0019] like Figure 1 As shown, the embodiment of the present application provides a method for calculating the coastal flow of pollutant tracking particles in a complex coastline environment, including the following steps:

[0020] Step S1: Based on the hazardous chemical leakage model of the Lagrangian particle tracing algorithm, spatial judgment of particle trajectory vectors and shoreline segment vectors is introduced.

[0021] As a preferred example, see Figure 2 , this step is as follows:

[0022] (1) In the Lagrangian particle tracing algorithm, the particle's previous position point A (coordinates: X0, Y0) and the next position point B (coordinates: X4, Y4) are confirmed, and the particle trajectory vector is constructed. .

[0023] (2) The particle trajectory vector The particle is spatially judged by the shoreline segment vector formed between each node of the shoreline. If the two vectors intersect, it means that the particle will collide with the shoreline segment vector at the next moment, confirming the collision. Intersecting shoreline fragment vector , where the coordinates of point E are (X1, Y1) and point F are (X5, Y5), calculate and Angle .

[0024] (3) Confirmation and The intersection point G (coordinates: X6, Y6) of the particle trajectory vector is calculated. In combination with the fluid motion characteristics and taking into account the continuity and stability of the subsequent judgment of the particle's flow around the shore, point G is not directly used as the trajectory deflection point after the particle trajectory vector hits the shore. Instead, point C (coordinates: X2, Y2) is calculated and used as the trajectory deflection point after the particle trajectory vector hits the shore.

[0025] Furthermore, the coordinates of point C are calculated as follows:

[0026] ,

[0027] in The shore coefficient of the particle trajectory vector is 0.9 by default.

[0028] Step S2: Calculate the vector offset of the particle after it collides with the shoreline based on the particle predicted vector trajectory and the shoreline segment vector.

[0029] As a preferred example, this step is specifically as follows:

[0030] (1) Assuming that the trajectory vector of the particle that hits the shore is offset, the next moment the particle is at point D (coordinates X3, Y3). The coordinates of point D will be solved based on the known points A, B, C, E, and F.

[0031] (2) Calculation and The dot product value S is:

[0032]

[0033] (3) Using point D coordinate expression and The dot product value and and The cross product value of :

[0034]

[0035]

[0036] (4) Calculate the coordinates of point D based on the above two equations

[0037]

[0038]

[0039] in The particle kinetic energy retention coefficient is 1 by default, indicating that no kinetic energy loss occurs after the particle collides with the shoreline.

[0040] Step S3: Based on the offset vector after the particle collides with the shoreline, continue to perform spatial judgment on the particle motion trajectory and the shoreline segment vector, and continue to calculate the vector offset after the particle trajectory collides with the shoreline until the particle no longer collides with the shoreline.

[0041] As a preferred example, this step is specifically as follows:

[0042] (1) Based on the offset vector after the particle hits the shoreline , repeat the spatial judgment of the particle trajectory vector and the shoreline segment vector in step S1;

[0043] (2) If the particle trajectory vector intersects with a certain shoreline segment vector again, return to step S2 and calculate the vector offset after the particle collides with the shoreline; if the particle trajectory vector no longer intersects with the shoreline segment vector, enter step S4.

[0044] Step S4: The final offset position of the particle after colliding with the shoreline is transmitted back to the hazardous chemical leakage model, and the model continues the simulation prediction at the next time.

[0045] (1) Record the starting and ending points of each offset vector after the particle hits the shoreline;

[0046] (2) The final offset position after the particle collision shoreline calculation is sent back to the hazardous chemical leakage model.

[0047] (3) The hazardous chemical leakage model uses the final calculation result of the particle coasting algorithm as the starting position of the particle at the next moment, and continues to simulate the drift, diffusion and destination processes of dissolved or low-viscosity pollutant particles.

[0048] Corresponding to the method embodiment, the present application also provides a pollutant tracking particle coastal flow calculation device, comprising:

[0049] memory for storing computer programs;

[0050] The processor is used to call and execute the computer program to implement the various steps of the pollutant tracking particle alongshore flow calculation method as described above.

[0051] Corresponding to the method embodiment, the present application also provides a storage medium on which a computer program is stored. When the computer program is executed by a processor, the various steps of the pollutant tracking particle alongshore flow calculation method are implemented.

[0052] Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0053] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0054] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present application. Various modifications to these embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for calculating the coastal flow of pollutant tracking particles in a complex coastal environment, characterized by The method comprises the following steps: Step 1. Based on the hazardous chemical leakage model of the Lagrangian particle tracing algorithm, a spatial judgment between the particle trajectory vector and the shoreline segment vector is introduced to determine whether the particle trajectory vector intersects with the shoreline segment vector. If so, the intersection point and the intersecting shoreline segment vector are determined; Step 2. Based on the particle prediction vector trajectory and the shoreline segment vector, the vector offset after the particle hits the shoreline is calculated, and the trajectory deflection point after the particle hits the shoreline is determined; Step 3. Based on the vector offset after the particle collides with the shoreline, continue to determine the spatial relationship between the particle trajectory and the shoreline segment vector, and continue to calculate the vector offset after the particle trajectory collides with the shoreline until the particle no longer collides with the shoreline; Step 4. The final offset position of the particle after colliding with the shoreline is transmitted back to the hazardous chemical leakage model. The hazardous chemical leakage model uses the final offset position as the starting position of the particle at the next moment and continues the simulation prediction.

2. The method for calculating the coastal flow of pollutant tracking particles according to claim 1 is characterized in that: In step 1, the spatial determination of the particle trajectory vector and the shoreline segment vector specifically includes: Confirm the particle's previous moment position A and next moment position B, and construct the particle trajectory vector; The particle trajectory vector and the shoreline segment vector formed between each shoreline node are spatially judged. If the two vectors intersect, the intersecting shoreline segment vector is confirmed, and the angle between the particle trajectory vector and the shoreline segment vector is calculated.

3. The method for calculating the coastal flow of pollutant tracking particles according to claim 2, characterized in that: In step 1, the intersection point G is confirmed, and point C is calculated based on the fluid motion characteristics and the continuity and stability of the particle's subsequent flow around the shore. Point C is used as the trajectory deflection point after the particle trajectory vector hits the shore.

4. The method for calculating the coastal flow of pollutant tracking particles according to claim 3 is characterized in that: In step 2, calculating the vector offset after the particle collides with the shoreline specifically includes: Assume that after the trajectory vector of the particle hitting the shore is deflected, the position of the particle at the next moment is point D; Calculate particle trajectory vector Offset vector from particle trajectory The dot product value S; The dot product value S and the particle trajectory vector are expressed using the coordinates of point D. With shoreline fragment vector The cross product value of The coordinates of point D are reversely solved using the dot product value S and the cross product value.

5. The method for calculating the coastal flow of pollutant tracking particles according to any one of claims 1 to 4, characterized in that: In step 3, based on the offset vector after the particle collides with the shoreline, the spatial judgment of the particle trajectory vector and the shoreline segment vector in step 1 is repeated; if the particle trajectory vector intersects with a shoreline segment vector again, return to step 2 and calculate the vector offset after the particle collides with the shoreline; if the particle trajectory vector no longer intersects with the shoreline segment vector, enter step 4.

6. The method for calculating the coastal flow of pollutant tracking particles according to any one of claims 1 to 4, characterized in that: In step 4, the starting and ending points of each offset vector after the particle collides with the shoreline are recorded, and the final offset position after the particle collides with the shoreline is calculated and transmitted back to the hazardous chemical leakage model. The hazardous chemical leakage model uses the final offset position as the starting position of the particle at the next moment and continues to simulate the drift, diffusion and destination processes of dissolved or low-viscosity pollutant particles.

7. The method for calculating the coastal flow of pollutant tracking particles according to claim 3, characterized in that: The shore-distance coefficient of the particle trajectory vector is introduced in the process of calculating point C to adjust the position of the trajectory deflection point after the particle trajectory vector hits the shore.

8. The method for calculating the coastal flow of pollutant tracking particles according to claim 4, characterized in that: The particle kinetic energy retention coefficient is introduced in the calculation process of point D to represent the kinetic energy loss of particles after colliding with the shoreline.

9. A pollutant tracking particle alongshore flow calculation device, characterized in that: include: Memory for storing computer programs; The processor is configured to call and execute the computer program to implement the various steps of the pollutant tracking particle alongshore flow calculation method according to any one of claims 1 to 8.

10. A storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed by a processor, each step of the method for calculating the coastal flow of pollutant tracking particles as described in any one of claims 1 to 8 is implemented.

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