Numerical Simulation Method for Wave Absorption of Wave Impacting Structures Based on SPH

Abstract

This application discloses a numerical simulation method for wave impact suppression of structures based on SPH (Self-Pulsating Hypothesis), relating to the field of data processing technology. The method includes the following steps: determining multiple critical regions and absorbing layer particles in a preset fluid domain; calculating the critical stability of each anchor point at different times based on the position and state update of each critical particle; updating each anchor point based on the critical stability to obtain multiple final anchor points; calculating the repulsive force adjustment coefficient of each critical particle based on the repulsive force adjustment requirement of each final anchor point and the disturbance degree of the critical particles; adjusting the repulsive force of each critical particle using the repulsive force adjustment coefficient; and performing wave suppression processing on each critical particle based on the adjusted repulsive force and the absorbing layer particles. This application achieves the technical effect of completely and effectively absorbing all transmitted waves in the wave impact simulation process.

Description

Technical Field

[0001] This application relates to the field of data processing technology, and in particular to a numerical simulation method for wave impact reduction of structures based on SPH. Background Technology

[0002] In the field of marine engineering, traditional wave-structure interactions are typically simulated using a mesh-based discrete computational domain. Among these methods, Smoothed Particle Hydrodynamics (SPH), as an emerging meshless approach, is frequently used for numerical simulations of marine engineering problems. For the process of waves impacting structures, the simulation process usually mimics the approach of physical model experiments. Furthermore, the end of the tank in the experiment needs to achieve a non-reflective boundary condition. The non-reflective boundary condition aims to make the waves (or disturbances) reaching the boundary "unaware" of the boundary's existence, as if the waves could freely pass through the boundary and propagate to infinity, thereby maximizing the absorption of the wave's energy and preventing it from being reflected back into the computational domain.

[0003] When using the SPH method to perform wave attenuation numerical simulations after wave impact on structures, the structure is represented by boundary particles, and the waves are represented by flowing particles. By applying a reverse force to the flowing particles, the kinetic energy of the flowing layer particles is counteracted to absorb the arriving transmitted waves, thus achieving a non-reflective boundary condition in the current simulation method. However, due to the different construction of boundary particles of the structure and the influence of its neighboring particles on the flowing particles, the pressure field or velocity field of the wave morphology near the wave attenuation area is discontinuous. As a result, the acceleration of each fluid particle is different, and it is impossible to completely and effectively absorb all the transmitted waves. Summary of the Invention

[0004] The main objective of this application is to provide a numerical simulation method for wave impact structure wave absorption based on SPH, which aims to solve the technical problem in related technologies where the pressure field or velocity field of the wave morphology is discontinuous near the wave absorption area, resulting in different accelerations of various fluid particles and the inability to completely and effectively absorb all transmitted waves.

[0005] To achieve the above objectives, embodiments of this application provide a numerical simulation method for wave impact mitigation of structures based on SPH, comprising:

[0006] Multiple critical regions and absorption layer particles are identified in a preset fluid domain, wherein the critical regions include multiple fluid particles, and the fluid particles include anchor points and multiple critical particles.

[0007] Based on the position and state update of each critical particle, the critical stability of each anchor point at different times is calculated.

[0008] Based on the critical stability level, each anchor point is updated to obtain multiple final anchor points;

[0009] Based on the repulsive force adjustment requirement of each final anchor point and the degree of disturbance of the critical particles, the repulsive force adjustment coefficient of each critical particle is calculated.

[0010] The repulsive force of each critical particle is adjusted by a repulsive force adjustment coefficient, and wave-damping treatment is performed on each critical particle based on the adjusted repulsive force and the particles in the absorption layer.

[0011] In one possible implementation of this application, the critical stability of each anchor point at different times is calculated based on the position and state update of each critical particle, including:

[0012] Determine the particle acceleration of each critical particle;

[0013] Based on the positional differences of each critical particle between adjacent time points and the variance of particle acceleration, the critical stability of each anchor point at different time points is calculated. The variance of particle acceleration is used to characterize the state update of the acceleration corresponding to each critical particle.

[0014] In one possible implementation of this application, each anchor point is updated based on the critical stability level to obtain multiple final anchor points, including:

[0015] The critical stability of each anchor point at the current time is classified by a preset classification threshold to obtain the first critical stability and the second critical stability.

[0016] Determine the range of the mean values ​​between the first critical stability level and the second critical stability level;

[0017] When the range value is greater than the first preset threshold, multiple new final anchor points are selected from the fluid particles based on the local density of each fluid particle.

[0018] In one possible implementation of this application, before classifying the critical stability of each anchor point at the current time using a preset classification threshold to obtain the first critical stability and the second critical stability, the method further includes:

[0019] For any anchor point, determine the critical stability level at each time point from the start time to the current time;

[0020] Based on the critical stability at each time point, a critically stable data sequence is constructed;

[0021] The algorithm calculates multiple residual terms of the critically stable data sequence and the inverse proportional normalized value of the standard deviation of each residual term.

[0022] The inverse proportional normalized value is used as the critical stability of each anchor point at the current moment.

[0023] In one possible implementation of this application, the critical stability of each anchor point at the current time is classified by a preset classification threshold to obtain a first critical stability and a second critical stability, including:

[0024] Compare the critical stability of each anchor point at the current moment with the Otsu threshold;

[0025] If the critical stability level is less than or equal to the Otsu threshold, the critical stability level is classified as the first critical stability level; otherwise, it is classified as the second critical stability level.

[0026] In one possible implementation of this application, multiple new final anchor points are selected from the fluid particles based on the local density of each fluid particle, including:

[0027] Determine the first number of anchor points corresponding to the first critical stability level, and calculate the local density of fluid particles other than the anchor points corresponding to the second critical stability level;

[0028] The local densities are sorted in descending order, and the fluid particles with the highest density before sorting are selected as the new anchor points.

[0029] Based on the nearest neighbor clustering algorithm and the new anchor points, all fluid particles are re-clustered to obtain several new anchor points and their critical particles. The update stops when the distance between the critical particle of the new anchor point and the particles of the absorption layer is less than the preset repulsive force range, resulting in multiple final anchor points.

[0030] In one possible implementation of this application, before calculating the repulsion adjustment coefficient of each critical particle based on the repulsion adjustment requirement of each final anchor point and the degree of disturbance of the critical particle, the method further includes:

[0031] The first duration of each final anchor point is obtained as the anchor point, and the second duration is obtained from the start time to the moment when the critical particle corresponding to the final anchor point comes into contact with the absorption layer particle.

[0032] Based on the ratio of the first duration to the second duration, and the critical stability of each final anchor point at the moment of contact between the critical particle and the absorbing layer particle, the repulsive force adjustment requirement of each final anchor point is calculated.

[0033] In one possible implementation of this application, the repulsion force adjustment coefficient of each critical particle is calculated based on the repulsion force adjustment requirement of each final anchor point and the degree of disturbance of the critical particle, including:

[0034] The moment when the critical particle comes into contact with the particles in the absorption layer is determined as the final moment.

[0035] Obtain the number of critical particles whose motion is directed between the particles in the absorption layer at the final moment;

[0036] The degree of disturbance to the critical particles is determined based on the ratio between the number of particles and the number of critical particles at each final anchor point at the final moment.

[0037] Based on the repulsion force adjustment requirement of each final anchor point, the degree of disturbance of critical particles, and the edge angle between each critical particle and the wave impact structure corresponding to the absorbing layer particles, the repulsion force adjustment coefficient of each critical particle is calculated.

[0038] In one possible implementation of this application, the repulsive force of each critical particle is adjusted using a repulsive force adjustment coefficient, including:

[0039] Based on the preset repulsive force calculation formula and repulsive force adjustment coefficient, the repulsive force of each critical particle is reduced.

[0040] In one possible implementation of this application, based on the adjusted repulsive force and the particles in the absorbing layer, wave attenuation processing is performed on each critical particle, including:

[0041] Based on the adjusted repulsive force, the first acceleration of each critical particle is calculated.

[0042] A second acceleration, with the same value but opposite direction as the first acceleration, is applied to the absorption layer particles to which the direction of motion of each critical particle is directed;

[0043] The kinetic energy of each critical particle is counteracted by a second acceleration to perform wave-damping treatment on each critical particle.

[0044] This application provides a numerical simulation method for wave impact suppression of structures based on SPH (Surface Heating and Dissipation). Compared to related technologies where the wave morphology is discontinuous in the pressure or velocity field near the suppression region, resulting in different accelerations for fluid particles and the inability to effectively absorb all transmitted waves, this application determines multiple critical regions and absorbing layer particles within a preset fluid domain. Each critical region includes anchor points and multiple critical particles other than the anchor points. Based on the position and state update of each critical particle, the critical stability degree of each anchor point at different times is calculated. Then, the anchor points are updated based on the critical stability degree to obtain multiple final anchor points. The repulsive force adjustment requirement of the anchor point and the degree of interference of the critical particles are used to calculate the repulsive force adjustment coefficient of each critical particle. The repulsive force of each critical particle is adjusted according to the repulsive force adjustment coefficient. Based on the adjusted repulsive force and the particles in the absorption layer, the wave attenuation treatment of each critical particle is performed. By analyzing the critical stability of each anchor point, each anchor point is continuously updated. Based on the degree of interference of the critical particles and the final repulsive force adjustment requirement of the anchor point, the repulsive force adjustment coefficient is determined. The repulsive force to be applied to each critical particle is adjusted according to the repulsive force adjustment coefficient to eliminate the acceleration and kinetic energy of each critical particle, thereby completely and effectively absorbing all transmitted waves. Attached Figure Description

[0045] Figure 1 This is a flowchart illustrating the first embodiment of the wave impact mitigation numerical simulation method for wave-impact structures based on SPH in this application.

[0046] Figure 2 This is a schematic diagram of fluid particle distribution in the fluid domain involved in the wave impact structure wave damping numerical simulation method based on SPH in this application;

[0047] Figure 3 This is a schematic diagram of the device structure of the hardware operating environment involved in the embodiments of this application. Detailed Implementation

[0048] It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit this application.

[0049] This application provides a numerical simulation method for wave impact mitigation of structures based on SPH (Surge Power Physics). In the first embodiment of this application's numerical simulation method for wave impact mitigation of structures based on SPH, referring to... Figure 1 ,include:

[0050] Step S10: Determine multiple critical regions and absorption layer particles in a preset fluid domain, wherein the critical regions include multiple fluid particles, and the fluid particles include anchor points and multiple critical particles.

[0051] Step S20: Based on the position and state update of each critical particle, calculate the critical stability of each anchor point at different times.

[0052] Step S30: Based on the critical stability level, update each anchor point to obtain multiple final anchor points;

[0053] Step S40: Based on the repulsion force adjustment requirement of each final anchor point and the degree of disturbance of the critical particles, calculate the repulsion force adjustment coefficient of each critical particle.

[0054] Step S50: Adjust the repulsive force of each critical particle using the repulsive force adjustment coefficient, and perform wave-damping treatment on each critical particle based on the adjusted repulsive force and the particles in the absorption layer.

[0055] This embodiment aims to: determine the repulsion force adjustment coefficient based on the degree of interference of the critical particles and the repulsion force adjustment requirement of the final anchor point, and then adjust the repulsion force to be applied to each critical particle according to the repulsion force adjustment coefficient, so as to eliminate the acceleration and kinetic energy of each critical particle, and thus completely and effectively absorb all transmitted waves.

[0056] The specific steps are as follows:

[0057] Step S10: Determine multiple critical regions and absorption layer particles in a preset fluid domain, wherein the critical regions include multiple fluid particles, and the fluid particles include anchor points and multiple critical particles.

[0058] As an example, the wave impact structure wave damping numerical simulation method based on SPH can be applied to the wave impact structure wave damping numerical simulation device based on SPH. The wave impact structure wave damping numerical simulation device based on SPH belongs to the wave impact structure wave damping numerical simulation system based on SPH, and the wave impact structure wave damping numerical simulation system based on SPH belongs to the wave impact structure wave damping numerical simulation equipment based on SPH.

[0059] As an example, the preset fluid domain is a pre-constructed rectangular fluid domain used to simulate the process of waves impacting a structure. When using the boundaryless condition to achieve wave dissipation in numerical simulation, a portion of the multi-layer boundary particles of the structure are used as absorbing layer particles to avoid the echo generated after the waves collide with the impacting structure, which would affect the subsequent collision between the flowing particles and the impacting structure.

[0060] As an example, the characteristic length of the fluid region in a rectangular fluid domain is L, and N is the total number of fluid particles, thus obtaining the interparticle spacing. Where d is the dimension of the fluid particle, and each fluid particle is uniformly distributed on one side of the rectangular fluid domain, the obtained position parameters are... In the preset fluid domain, the density of each fluid particle is the same as m, and the hydrostatic pressure is... The velocity of the stationary fluid is v; the pressure P on each particle is calculated using the Tait equation, and the particle generates an initial vector acceleration a under this pressure.

[0061] For boundary particles, based on the shape of the wave-impacted structure, three layers of boundary particles are distributed on the other side of the rectangular fluid domain. The outermost boundary particles are used as the absorbing layer particles. Therefore, based on the above data, this application can simulate the pressure and acceleration of fluid particles at various times and change their position parameter r in real time to obtain the position parameter of the i-th fluid particle at time t. .

[0062] As an example, the boundary of an impact structure and the distribution of fluid particles are shown in the diagram. Figure 2 As shown, each circular particle is a fluid particle, and the circles represent the demarcated critical regions. The particles surrounding the particle indicated by the arrow represent the neighboring particles of the current particle. The left side of the figure shows the distribution of fluid particles, and the right side shows the boundary distribution.

[0063] As an example, in a fluid dynamics model, the higher the density of fluid particles, the greater the pressure and the stronger the acceleration. Therefore, the initial anchor point and local region selection are performed for all fluid particles in the initial state (t=0). All fluid particles are divided into several critical regions. The fluid particle at the center of each critical region is recorded as the anchor point of each critical region, and the other fluid particles in the critical region of each anchor point are the critical particles of that anchor point.

[0064] Step S20: Based on the position and state update of each critical particle, calculate the critical stability of each anchor point at different times.

[0065] As an example, in the initial state, the spacing between each fluid particle is equal. However, due to the influence of other boundaries of the rectangular fluid domain, and the fact that even a tiny error during the iteration process can cause a large-area particle turbulence effect, the anchor point itself deviates from the initial position of the fluid particles to the position of the boundary particles at different times. Furthermore, its critical particles escape from their critical regions into the critical regions of other anchor points. The more frequently particles escape from the critical region and the more new particles enter the critical region, the higher or lower the density of critical particles in the anchor point will be, thus affecting the kinetic energy of the critical particles and causing fine waves.

[0066] As an example, based on the position updates of each critical particle and the changes / updates of acceleration, the stability of each anchor point at each time step is determined, thereby calculating the critical stability of each anchor point. The critical stability is used to represent the stability of each critical region. When frequent particle escapes or additions occur in the critical region corresponding to each anchor point, it indicates that the stability of the local area where this anchor point is located is smaller.

[0067] Among them, step S20 of the wave impact damping numerical simulation based on SPH for wave impact structures also includes steps S21~S22, including:

[0068] Step S21: Determine the particle acceleration of each critical particle.

[0069] As an example, after determining each critical region, the particle acceleration of the critical particle in the critical region can be obtained directly.

[0070] Step S22: Based on the positional differences of each critical particle between adjacent time points and the variance of particle acceleration, the critical stability of each anchor point at different time points is calculated. The variance of particle acceleration is used to characterize the state update of the acceleration corresponding to each critical particle.

[0071] As an example, let's take the critical stability of the i-th anchor point at time t as an example. The calculation method can be:

[0072]

[0073] in, Let be the critical stability level of the i-th anchor point at time t. The initial number of critical particles in each critical region. Let represent the number of critical particles at the i-th anchor point at time t. This represents the standardized difference in the number of critical particles between two adjacent time points. A value less than 0 indicates a decrease in density and an increase in stability, while a value greater than 0 indicates an increase in the number of critical particles at the current time point compared to the previous time point. The greater the increase and the greater the difference from the preset number... The larger the value, the more particles are present in the critical region of the i-th anchor point. Therefore, as density increases, pressure increases. With increased pressure, the acceleration of fluid particles also increases, reflecting the direction and magnitude of the acceleration vector. The more discrete, the more... Let a represent the variance of the acceleration of each critical particle at the i-th anchor point at time t, where a represents the acceleration, q represents the q-th critical particle, and exp is the natural constant. Similarly, the critical stability at different times can be calculated.

[0074] Step S30: Based on the critical stability level, update each anchor point to obtain multiple final anchor points.

[0075] As an example, in the simulation of flowing particles, the direction of particle motion is only related to the pressure it is subjected to. This means that if a critical region is adjacent to a critical region at a density in the previous moment, a large number of critical particles in that critical region will escape into the surrounding critical regions at the next moment, thus increasing the number of critical particles in the surrounding critical regions. However, at the moment after that, only some of the previously escaped critical particles return to that critical region, while the rest escape into other critical regions surrounding the surrounding critical regions. This causes the number of critical particles in the initially high-density critical region and its surrounding critical regions to decrease at the moment after that, exhibiting a regional change in the number of critical particles.

[0076] From a macroscopic perspective, this phenomenon manifests as localized high and low densities within the critical regions of the anchor points. Critical regions with localized low densities are more easily canceled out when reaching particles in the absorbing layer, while critical regions with localized high densities require adjustments to the repulsive force of the absorbing layer particles to cope with the increased number of critical particles and thus mitigate the wave. Based on this localized density variation, the anchor points in each critical region need to be updated to ensure a uniform distribution of the local density of critical particles near each anchor point. This allows for accurate calculation of the repulsive force of different anchor points and their corresponding critical particles.

[0077] The step S30, which updates each anchor point based on the critical stability level to obtain multiple final anchor points, includes:

[0078] Step S31: Classify the critical stability of each anchor point at the current time using a preset classification threshold to obtain the first critical stability and the second critical stability.

[0079] As an example, the anchor point itself is the unit used in this application to observe the kinetic energy form of flowing particles. Therefore, attention should be focused on high-density regions, and attention should be reduced to low-density regions. Thus, the selection of anchor points needs to be updated so that the observation anchor points are mainly in high-density regions. Then, the critical stability of each anchor point is classified by a preset classification threshold, thereby dividing high-density regions and low-density regions.

[0080] Before step S31, the following steps are also included:

[0081] For any anchor point, determine the critical stability level at each time point from the start time to the current time;

[0082] Based on the critical stability at each time point, a critically stable data sequence is constructed.

[0083] As an example, if a critical particle escapes from one of two adjacent critical regions to the other, the number of fluid particles in the other critical region will be higher than that in the region where the escape occurred. In the next moment, because the density of the newly added particles in the critical region is greater than that in the region where the escape occurred, the pressure increases and the acceleration reverses, causing the critical particles to escape from the high-density critical region to the low-density critical region. This continues, resulting in a vicious cycle of stability oscillations over a sustained period. Therefore, this application obtains the critical stability of each anchor point at each moment based on the changes in the stability of the anchor point over historical moments.

[0084] As an example, taking the i-th anchor point at time t as an example, the stability of the i-th anchor point from the start time to time t (the current time) is constructed as a sequence. In this sequence, the critical stability at each time corresponds to a sequence value.

[0085] The algorithm calculates multiple residual terms of the critically stable data sequence and the inversely proportional normalized value of the standard deviation of each residual term.

[0086] The inverse proportional normalized value is used as the critical stability of each anchor point at the current moment.

[0087] As an example, the default algorithm is the STL algorithm (Loess-based seasonal-trend decomposition algorithm), which is existing technology and will not be elaborated here. After calculating multiple residual terms of the critically stable data sequence, a residual term sequence is generated. Finally, the inverse proportional normalized value of the standard deviation corresponding to each residual term is used as the critical stability of the current anchor point at the current time. Similarly, the critical stability of each anchor point at the current time is obtained.

[0088] Specifically, the residual term measures the volatility of the sequence. The larger the standard deviation of the residual value, the greater the volatility, which is more in line with the stability oscillation caused by escape and addition. Therefore, the larger the standard deviation, the greater the oscillation and the smaller the critical stability.

[0089] The step S31, which involves classifying the critical stability of each anchor point at the current moment using a preset classification threshold to obtain the first critical stability and the second critical stability, includes:

[0090] The critical stability of each anchor point at the current moment is compared with the Otsu threshold.

[0091] If the critical stability level is less than or equal to the Otsu threshold, the critical stability level is classified as the first critical stability level; otherwise, it is classified as the second critical stability level.

[0092] As an example, the preset classification threshold can be the Otsu threshold. The Otsu threshold is a grayscale threshold determined by an algorithm that automatically determines the image binarization threshold. This algorithm is existing technology. In this application, the critical stability of each anchor point is classified by this threshold, thereby classifying the density in each critical region and determining high-density regions and low-density regions respectively.

[0093] As an example, the critical stability is negatively correlated with density; the higher the critical stability, the lower the density. If the critical stability is less than or equal to the Otsu threshold, the critical stability is divided into the first critical stability, and the critical region corresponding to the first critical stability is the high-density region. Similarly, the critical region corresponding to the second critical stability is the low-density region.

[0094] Step S32: Determine the range of the mean values ​​between the first critical stability level and the second critical stability level.

[0095] As an example, both the first and second critical stability levels include multiple critical stability values. The range between the two average values ​​is determined. The larger the range, the more obvious the density stratification effect in the current fluid domain.

[0096] As an example, let's calculate the range at time t. The method can be:

[0097]

[0098] The mean value representing the second critical stability level. The mean value representing the first critical stability level. The range of the mean critical stability values ​​in the two classes is denoted as t. The larger the range, the more the critical stability of each anchor point at time t is divided into two classes: one is high-density and the other is low-density.

[0099] Step S33: When the range value is greater than the first preset threshold, select multiple new final anchor points from the fluid particles based on the local density of each fluid particle.

[0100] As an example, the first preset threshold can be 0.4, 0.5, etc., and there is no specific limitation.

[0101] As an example, areas with lower critical stability correspond to high-density anchor points, which are regions of interest. Conversely, areas with higher critical stability correspond to low-density areas, which receive less attention and therefore need to be deprived of observation privileges. This allows observation privileges to be primarily placed in high-density areas. So, when... When the value is greater than the preset threshold of 0.4, it indicates that density stratification has occurred, and the anchor point needs to be updated and iterated to select a new anchor point.

[0102] As an example, the final anchor point is determined when the distance between the critical particle and the absorbing layer particles is within the range of the repulsive force. At this point, the anchor point stops updating, and it will continue to iterate and update until this moment.

[0103] The step S33, which selects multiple new final anchor points from the fluid particles based on the local density of each fluid particle, includes:

[0104] Determine the first number of anchor points corresponding to the first critical stability level, and calculate the local density of fluid particles other than the anchor points corresponding to the second critical stability level.

[0105] The local densities are sorted in descending order, and the fluid particles with the highest density before sorting are selected as the new anchor points.

[0106] As an example, the first quantity can be the number of anchor points corresponding to high-density regions, and the second critical stability level corresponds to low-density regions. The anchor points in these regions do not need to be updated. Therefore, the local density of fluid particles other than the anchor points corresponding to the second critical stability level is calculated, and new anchor points are selected based on the local density of each fluid particle.

[0107] As an example, after calculating the local density of each fluid particle, the local densities are sorted in descending order. Based on the local density, the fluid particles with the highest number of particles in the sort are selected as new anchor points. The number of new anchor points selected is consistent with the number of anchor points corresponding to the first critical stability level. When the first number is 5, the top 5 fluid particles in the sort are selected as new anchor points.

[0108] Based on the nearest neighbor clustering algorithm and the new anchor points, all fluid particles are re-clustered to obtain several new anchor points and their critical particles. The update stops when the distance between the critical particle of the new anchor point and the particles of the absorption layer is less than the preset repulsive force range, resulting in multiple final anchor points.

[0109] As an example, after selecting a new anchor point, the nearest neighbor algorithm is used to cluster the new anchor point and other fluid particles to obtain multiple new anchor points and their critical particles. This process is repeated, and the critical stability of the anchor point is calculated at each time point. The anchor points are updated and deactivated using the range value until the distance between the critical particle of the anchor point and the particles in the absorption layer is less than the equilibrium distance / preset repulsive force range. These new anchor points are then recorded as the final anchor points. When the update stops, all anchor points are final anchor points, not just those that have changed.

[0110] As an example, the equilibrium distance is the range of the repulsive force. It is related to the smoothness length h (the range of the kernel function, the radius of local influence carried by each particle, which determines the range of interaction between the particle and its neighbors), and is usually [value missing]. The kernel function is a function of the kinetic energy generated by factors such as mass, distance from neighboring particles, particle kinetic energy, and pressure, so as to realize the continuity of discrete particles in a rectangular fluid domain.

[0111] Step S40: Based on the repulsion force adjustment requirement of each final anchor point and the degree of disturbance of the critical particles, the repulsion force adjustment coefficient of each critical particle is calculated.

[0112] As an example, the repulsive force adjustment requirement of the final anchor point is calculated based on the critical stability of the anchor point in historical time. Since the acceleration of the critical particle changes when disturbed, and the repulsive force required to be applied will also change accordingly when the acceleration changes, the repulsive force adjustment coefficient of each critical particle is calculated by combining these two factors.

[0113] As an example, the repulsive force adjustment coefficient indicates the degree to which the repulsive force needs to be adjusted. It is used to fine-tune the calculated repulsive force, thereby achieving wave elimination for each critical particle.

[0114] Before step S40, the following steps are also included:

[0115] The first duration of each final anchor point is obtained, and the second duration is obtained from the start time to the moment when the critical particle corresponding to the final anchor point comes into contact with the particle in the absorption layer.

[0116] Based on the ratio of the first duration to the second duration, and the critical stability of each final anchor point at the moment of contact between the critical particle and the absorbing layer particle, the repulsive force adjustment requirement of each final anchor point is calculated.

[0117] As an example, the first duration indicates how long the final anchor point has served as the anchor point. The longer the duration, the more likely the fluid particle has been serving as the anchor point and has not participated in the deactivation and update process.

[0118] As an example, the second duration is the total duration from the start time to the moment when the critical particle and the absorbing layer particle come into contact at the final anchor point.

[0119] As an example, anchor points and their critical particles in high-density regions are more susceptible to the influence of mutual particles. That is, the repulsive force calculated at the current moment may become too large at the next moment due to the mutual influence of the anchor points and their fluid particles, which in turn causes the fluid particles to bounce back or even cause the absorbing layer particles to escape from the boundary and become discrete particles (because the absorbing layer particles are also kept in a stable position by applying a force, and when there is an additional force, the particles will escape).

[0120] Therefore, the more stable the final anchor particle is, the smaller the degree of repulsive force adjustment is required; conversely, the greater the degree of repulsive force adjustment is required for high-density areas.

[0121] As an example, taking the i-th final anchor point as an example, the repulsive force adjustment requirement degree The calculation method can be:

[0122]

[0123] in, This is the ratio of the first duration of the i-th final anchor point as an anchor point to its second duration from time 0 (the start time) to the contact time (this total duration may vary for different anchor points due to the flexible movement of the particle). A larger value indicates greater instability, meaning the fluid particle has consistently served as an anchor point without participating in deactivation or renewal. Even if it is renewed, it can be selected as a new anchor point again, meaning it remains in a high-density region. For the i-th final anchor point in the last The critical stability at time step; the smaller the value, the higher the density. The moment indicates the moment when the critical particle comes into contact with the absorbing layer particles, or it can be the moment when the critical particle is within the range of influence of the absorbing layer particles.

[0124] The step S40, which calculates the repulsion force adjustment coefficient of each critical particle based on the repulsion force adjustment requirement of each final anchor point and the degree of disturbance of the critical particle, includes:

[0125] The moment when the critical particle comes into contact with the particles in the absorption layer is determined as the final moment.

[0126] Obtain the number of critical particles whose motion is directed towards the particles in the absorption layer at the final moment.

[0127] As an example, since the principle of wave impact structure resisting waves is to decompose large waves into low-energy small waves through its complex and porous structure, and absorb them through collision, so that the final waves are no longer destructive, the collision between the critical particles at the anchor point and the particles in the absorption layer is also related to the path of other fluid particles and the collision angle.

[0128] As an example, for the k-th critical particle at the i-th final anchor point, obtain the... The velocity and direction at any given moment are determined, and their orientation is obtained (since wave suppression is required when the equilibrium distance is reached, regardless of whether the orientation is towards or away from the absorption layer, the orientation is linked to the direction of the absorption layer particle as its orientation). The nearest absorption layer particle is then identified, and after connection, the number of particles between the critical particle and the absorption layer particle is determined. This number of particles can be 2, 3, etc.

[0129] The degree of disturbance to the critical particles is determined by the ratio between the number of particles and the number of critical particles at each final anchor point at the final moment.

[0130] Based on the repulsion force adjustment requirement of each final anchor point, the degree of disturbance of critical particles, and the edge angle between each critical particle and the wave impact structure corresponding to the absorbing layer particles, the repulsion force adjustment coefficient of each critical particle is calculated.

[0131] As an example, by obtaining the directions of all critical particles connected to the absorbing layer particles, and then combining this with the repulsive force adjustment requirement of the anchor point to which the critical particle belongs, the repulsive force adjustment coefficient of each critical particle can be obtained. :

[0132]

[0133] in, The repulsive force adjustment requirement for the i-th final anchor point indicates the current density and the situation of the surrounding particles. The larger the value, the more unstable the surrounding situation is, and the easier it is for the interaction between particles to weaken the kinetic energy. This refers to the number of particles that connect to its absorption layer particles via other critical particles along the path obtained after the above connection. The number of critical particles at time t for the i-th final anchor point The larger the ratio, the greater the interference from other adjacent particles when it finally reaches the surface of the absorption layer (weakening its kinetic energy), therefore the adjustment coefficient needs to be increased. Indicates the degree of interference. Let be the angle between the k-th critical particle and the edge of the wave-impacted structure, with a value ranging from . The further the angle is from 90 degrees, the weaker the impact force of the particles in the absorption layer, and therefore the greater the need to reduce the magnitude of the repulsive force.

[0134] Step S50: Adjust the repulsive force of each critical particle using the repulsive force adjustment coefficient, and perform wave-damping treatment on each critical particle based on the adjusted repulsive force and the particles in the absorption layer.

[0135] As an example, after calculating the repulsive force adjustment coefficient, according to the repulsive force method, The forces acting on the flowing particles according to the kernel function are: Given its inherent velocity v and unit time t, its acceleration can be obtained. The principle of wave attenuation is to apply a repulsive force to the absorbing particles during collision. This allows the following to be satisfied in the next moment. Then, the repulsive force of each critical particle can be calculated according to the formula.

[0136] As an example, after calculating the repulsive force, the kinetic energy of each critical particle is counteracted by applying a corresponding acceleration to the particles in the absorbing layer.

[0137] The step S50, which adjusts the repulsive force of each critical particle using a repulsive force adjustment coefficient, further includes:

[0138] Based on the preset repulsive force calculation formula and repulsive force adjustment coefficient, the repulsive force of each critical particle is reduced.

[0139] As an example, the pre-defined formula for calculating repulsive force is expressed as:

[0140]

[0141] in, This is the ratio of the velocity at the next moment to the velocity per unit time, which is the acceleration of the k-th critical particle at the i-th anchor point at the next moment. The resultant force of external forces acting on the k-th critical particle at the i-th anchor point at the current moment. Let the repulsive force of the k-th critical particle at the i-th anchor point be calculated using the Lennard-Jones method (prior art). This is the repulsive force adjustment coefficient for the k-th critical particle at the i-th anchor point. The range of the value is (0,1). Since the particle's kinetic energy will decrease due to other disturbances, after calculating the repulsive force, the magnitude of its decrease can be determined.

[0142] The step S50, which involves performing wave-damping treatment on each critical particle based on the adjusted repulsive force and the particles in the absorbing layer, further includes:

[0143] Based on the adjusted repulsive force, the first acceleration of each critical particle is calculated.

[0144] A second acceleration, with the same value but opposite direction as the first acceleration, is applied to the absorption layer particles that are directed towards the direction of motion of each critical particle.

[0145] As an example, the adjusted repulsive force can be determined using the above formula, and then the first acceleration of the critical particle can be obtained, and the acceleration can be calculated. Then, a second acceleration, which is the same as the first acceleration but in the opposite direction, is applied to the absorption layer particle pointed to by the kth critical particle at the i-th anchor point.

[0146] The kinetic energy of each critical particle is counteracted by a second acceleration to perform wave-damping treatment on each critical particle.

[0147] As an example, the kinetic energy of the kth critical particle at the i-th anchor point is counteracted by the second acceleration to achieve wave attenuation of the kth critical particle at the i-th anchor point. Similarly, wave attenuation can also be performed on other critical particles.

[0148] This application provides a numerical simulation method for wave impact suppression of structures based on SPH (Surface Heating and Dissipation). Compared to related technologies where the wave morphology is discontinuous in the pressure or velocity field near the suppression region, resulting in different accelerations for fluid particles and the inability to effectively absorb all transmitted waves, this application determines multiple critical regions and absorbing layer particles within a preset fluid domain. Each critical region includes anchor points and multiple critical particles other than the anchor points. Based on the position and state update of each critical particle, the critical stability degree of each anchor point at different times is calculated. Then, the anchor points are updated based on the critical stability degree to obtain multiple final anchor points. The repulsive force adjustment requirement of the anchor point and the degree of interference of the critical particles are used to calculate the repulsive force adjustment coefficient of each critical particle. The repulsive force of each critical particle is adjusted according to the repulsive force adjustment coefficient. Based on the adjusted repulsive force and the particles in the absorption layer, the wave attenuation treatment of each critical particle is performed. By analyzing the critical stability of each anchor point, each anchor point is continuously updated. Based on the degree of interference of the critical particles and the final repulsive force adjustment requirement of the anchor point, the repulsive force adjustment coefficient is determined. The repulsive force to be applied to each critical particle is adjusted according to the repulsive force adjustment coefficient to eliminate the acceleration and kinetic energy of each critical particle, thereby completely and effectively absorbing all transmitted waves.

[0149] Reference Figure 3 , Figure 3 This is a schematic diagram of the device structure of the hardware operating environment involved in the embodiments of this application.

[0150] like Figure 3 As shown, the wave impact structure wave attenuation numerical simulation device based on SPH may include: a processor 1001, a memory 1003, and a communication bus 1002. The communication bus 1002 is used to realize the connection and communication between the processor 1001 and the memory 1003.

[0151] Optionally, the wave impact structure damping numerical simulation device based on SPH may also include a user interface, a network interface, a camera, RF (Radio Frequency) circuitry, sensors, a WiFi module, etc. The user interface may include a display screen and an input submodule such as a keyboard; optional user interfaces may also include standard wired or wireless interfaces. The network interface may include standard wired or wireless interfaces (such as a Wi-Fi interface).

[0152] Those skilled in the art will understand that Figure 3 The wave impact structure wave damping numerical simulation device structure shown in the figure does not constitute a limitation on the wave impact structure wave damping numerical simulation device based on SPH, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0153] like Figure 3 As shown, the memory 1003, serving as a storage medium, may include an operating system, a network communication module, and a wave impact structure wave damping numerical simulation program based on SPH (Surveyed Phenomenon Theory). The operating system is a program that manages and controls the hardware and software resources of the wave impact structure wave damping numerical simulation equipment based on SPH, supporting the operation of the wave impact structure wave damping numerical simulation program based on SPH and other software and / or programs. The network communication module is used to enable communication between the various components within the memory 1003, as well as communication with other hardware and software in the wave impact structure wave damping numerical simulation system based on SPH.

[0154] exist Figure 3 In the wave impact structure wave damping numerical simulation device shown, the processor 1001 is used to execute the wave impact structure wave damping numerical simulation program stored in the memory 1003, and implement the steps of the wave impact structure wave damping numerical simulation method described above.

[0155] The specific implementation of the wave impact damming numerical simulation equipment based on SPH for wave impact damming structures in this application is basically the same as the embodiments of the wave impact damming numerical simulation method based on SPH for wave impact damming structures described above, and will not be repeated here.

[0156] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0157] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0158] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0159] The above are merely preferred embodiments of this application and do not limit the scope of this application. Any equivalent structural or procedural transformations made based on the description and drawings of this application, or direct or indirect applications in other related technical fields, are similarly included within the scope of protection of this application.

[0160] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0161] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A numerical simulation method for wave impact mitigation of structures based on SPH, characterized in that, The method includes: Multiple critical regions and absorption layer particles are identified in a preset fluid domain, wherein the critical regions include multiple fluid particles, and the fluid particles include anchor points and multiple critical particles; Based on the position and state update of each critical particle, the critical stability of each anchor point at different times is calculated. Based on the critical stability level, each anchor point is updated to obtain multiple final anchor points; Based on the repulsion force adjustment requirement of each final anchor point and the degree of disturbance of the critical particle, the repulsion force adjustment coefficient of each critical particle is calculated. The repulsive force of each critical particle is adjusted using the repulsive force adjustment coefficient, and based on the adjusted repulsive force and the particles in the absorption layer, the critical particles are subjected to wave-damping treatment.

2. The numerical simulation method for wave impact damping structures based on SPH as described in claim 1, characterized in that, The calculation of the critical stability of each anchor point at different times, based on the position and state update of each critical particle, includes: Determine the particle acceleration of each of the critical particles; Based on the positional differences of each critical particle between adjacent time points and the variance of the particle acceleration, the critical stability of each anchor point at different time points is calculated, wherein the variance of the particle acceleration is used to characterize the state update of the acceleration corresponding to each critical particle.

3. The numerical simulation method for wave impact damping structures based on SPH as described in claim 1, characterized in that, Based on the critical stability level, each anchor point is updated to obtain multiple final anchor points, including: The critical stability of each anchor point at the current moment is classified by a preset classification threshold to obtain the first critical stability and the second critical stability. Determine the range of the mean values ​​between the first critical stability level and the second critical stability level; When the range value is greater than the first preset threshold, multiple new final anchor points are selected from the fluid particles based on the local density of each fluid particle.

4. The numerical simulation method for wave impact mitigation of structures based on SPH as described in claim 3, characterized in that, Before classifying the critical stability of each anchor point at the current time using a preset classification threshold to obtain the first critical stability and the second critical stability, the method further includes: For any anchor point, determine the critical stability level at each time point from the start time to the current time; Based on the critical stability at each time point, a critically stable data sequence is constructed; The algorithm calculates multiple residual terms of the critically stable data sequence using a preset algorithm, and calculates the inverse proportional normalized value of the standard deviation corresponding to each residual term. The inversely proportional normalized value is used as the critical stability of each anchor point at the current moment.

5. The numerical simulation method for wave impact mitigation of structures based on SPH as described in claim 3, characterized in that, The step of classifying the critical stability of each anchor point at the current time using a preset classification threshold to obtain a first critical stability and a second critical stability includes: Compare the critical stability of each anchor point at the current moment with the Otsu threshold. If the critical stability level is less than or equal to the Otsu threshold, then the critical stability level is classified as the first critical stability level; otherwise, the critical stability level is classified as the second critical stability level.

6. The numerical simulation method for wave impact mitigation of structures based on SPH as described in claim 3, characterized in that, The selection of multiple new final anchor points from the fluid particles based on their local density includes: Determine the first number of anchor points corresponding to the first critical stability level, and calculate the local density of fluid particles other than the anchor points corresponding to the second critical stability level; The local densities are sorted in descending order, and the first number of fluid particles before sorting is selected as the new anchor point. Based on the nearest neighbor clustering algorithm and the new anchor points, all fluid particles are re-clustered to obtain several new anchor points and their critical particles. The update stops when the distance between the critical particle of the new anchor point and the particles of the absorption layer is less than the preset repulsive force range, resulting in multiple final anchor points.

7. The numerical simulation method for wave impact damping structures based on SPH as described in claim 1, characterized in that, Before calculating the repulsion force adjustment coefficient of each critical particle based on the repulsion force adjustment requirement of each final anchor point and the degree of interference of the critical particle, the method further includes: The first duration of each final anchor point is obtained as the anchor point, and the second duration is obtained from the start time to the time when the critical particle corresponding to the final anchor point comes into contact with the particle of the absorption layer. Based on the ratio of the first duration to the second duration, and the critical stability of each final anchor point at the moment of contact between the critical particle and the absorber layer particle, the repulsive force adjustment requirement of each final anchor point is calculated.

8. The numerical simulation method for wave impact damping structures based on SPH as described in claim 1, characterized in that, The repulsive force adjustment coefficient of each critical particle is calculated based on the repulsive force adjustment requirement of each final anchor point and the degree of disturbance of the critical particle, including: The moment when the critical particle comes into contact with the particles in the absorption layer is determined as the final moment; At the final moment, the number of critical particles whose motion is directed between the particles in the absorption layer is obtained. The degree of interference of the critical particles is determined based on the ratio between the number of particles and the number of critical particles at each final anchor point at the final time. Based on the repulsion force adjustment requirement of each final anchor point, the degree of disturbance of the critical particles, and the edge angle between each critical particle and the wave impact structure corresponding to the absorbing layer particles, the repulsion force adjustment coefficient of each critical particle is calculated.

9. The numerical simulation method for wave impact damping structures based on SPH as described in claim 1, characterized in that, The adjustment of the repulsive force of each critical particle using the repulsive force adjustment coefficient includes: Based on the preset repulsive force calculation formula and the repulsive force adjustment coefficient, the repulsive force of each critical particle is reduced.

10. The numerical simulation method for wave impact damping structures based on SPH as described in claim 1, characterized in that, The process of performing wave-damping treatment on each of the critical particles based on the adjusted repulsive force and the particles in the absorbing layer includes: Based on the adjusted repulsive force, the first acceleration of each critical particle is calculated. A second acceleration, with the same value but opposite direction as the first acceleration, is applied to the absorption layer particles to which the direction of motion of each critical particle is directed; The second acceleration is used to counteract the kinetic energy of each critical particle in order to perform wave-damping treatment on each critical particle.

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