Bionic vortex anchoring filter for in-situ remediation of natural water body under actual hydrodynamic condition and application of bionic vortex anchoring filter

Abstract

The invention discloses a bionic vortex anchoring filter for in-situ remediation of a natural water body under an actual hydrodynamic condition and application, relates to the field of in-situ remediation of the natural water body, and aims at solving the problems that the remediation efficiency of pollutants in the natural water body under the actual hydrodynamic condition at present is low, and the problem that the recovery effect is influenced by fluid-solid coupling factors cannot be solved. The filter is composed of a deep sea glass sponge cavity framework and a flagellum type adsorbent. The vortex anchored filter (VAF) learns and utilizes a manner of biologically guiding functional vortex to prey, small-size vortex is initiated near an adsorbent to realize enhanced mass transfer, and the problem of low mass transfer efficiency accompanying in a high-flux treatment process is solved. The small-size eddy current near the adsorbent also has the effects of energy dissipation and transfer, and environmental turbulence energy is converted into rotational flow energy beneficial to mass transfer, so that the problems of unbalanced pressure and high fluid resistance caused by structure streaming are avoided. Therefore, the balance of mass transfer, hydrodynamic stability and trafficability is realized.

Description

Technical Field

[0001] The present invention belongs to the field of in-situ restoration of natural water bodies, and in particular relates to the design and preparation of an in-situ adsorption device for natural water bodies under actual hydrodynamic conditions. Background Art

[0002] Oil spills, improper discharge of chemical wastewater and domestic sewage can pollute natural water bodies, with the polluted water body reaching thousands of times the polluted water body, leading to long-term social, economic, environmental and ecological impacts. In order to avoid secondary pollution, it is often not possible to add agents to natural water bodies, so the common in-situ remediation method is to use corresponding adsorbent materials for in-situ remediation. Taking oil spills as an example, in the Deepwater Horizon accident in 2010 and the MT Princess Queen accident in 2023, the remediation team used adsorbent booms modified with oleophilic polymers such as polysiloxanes, organosilanes, polypropylene and polyurethane to collect the leaked oil. However, in harsh water flow environments, these intercepting in-situ remediation devices have uneven, unstable and uncontrollable fluid dynamics behaviors, resulting in inefficient or even ineffective interfacial mass transfer and oil capture effects. This problem is particularly evident in the case of pipeline leaks and offshore industrial emissions. Therefore, it is necessary to consider fluid-solid coupling factors and develop stable in-situ natural water remediation technologies suitable for complex water flow environments. Summary of the invention

[0003] The purpose of the present invention is to solve the problem that the pollutant remediation efficiency in natural water bodies under actual hydrodynamic conditions is low and the problem that fluid-solid coupling factors affect the recovery effect cannot be solved, and to provide a bionic vortex anchor filter and application for in-situ remediation of natural water bodies under actual hydrodynamic conditions.

[0004] The bionic vortex anchor filter for in-situ repair of natural water bodies under actual hydrodynamic conditions of the present invention is composed of a deep-sea glass sponge cavity skeleton and a flagella-type adsorbent.

[0005] Furthermore, the deep-sea glass sponge cavity skeleton is a hollow cylindrical structure, the outside of the hollow cylindrical structure is provided with spiral ridges, and the flagellar adsorbent is fixed on the periphery of the deep-sea glass sponge cavity skeleton.

[0006] Furthermore, the spiral ridge is formed by connecting "cut corner wedges", and the cut corner wedges are wedge-shaped bodies formed by cutting off two corners of a cube along the diagonal line; the side length of the original cube of the "cut corner wedge" without cutting the corners is L.

[0007] Furthermore, the deep-sea glass sponge cavity skeleton is a hollow cylindrical structure of a grid composed of a checkerboard lattice as a basic unit. The checkerboard lattice is composed of an "open square" with four-corner diagonal braces and a "closed square" with internal cross diagonal braces. The two types of squares are arranged in a staggered manner.

[0008] Furthermore, the side lengths of the "open grid" and the "closed grid" are both L, and the right-angled side length of the triangle formed by the diagonal support in the "open grid" is S; the size of the in-situ repair bionic eddy current anchor filter is determined based on the S / L and L values.

[0009] Furthermore, the length of the flagella of the flagella type adsorbent and the length of the oblique spiral ridge are the same as the side length L of the "open square" and the "closed square", and the width of the flagella of the flagella type adsorbent is 0.05L; the height of the bionic vortex anchor filter is 16L and the diameter is 10L.

[0010] The present invention provides a design method for a bionic vortex anchor filter for in-situ repair of natural water bodies under actual hydrodynamic conditions, and the design method is as follows:

[0011] Step 1: Obtain the fluid environment and contamination range, and determine the adsorption material and structure size:

[0012] (1a) Obtain information on fluid density, viscosity, flow rate, corrosiveness, and suspended solids size; as well as information on the type, density, viscosity, particle size, and contamination range of pollutants to be captured;

[0013] (1b) selecting appropriate bionic eddy current anchor filter skeleton material according to water corrosivity information;

[0014] Step 2, establish the geometric model and mathematical model of the bionic eddy current anchor filter skeleton-flagellum to be optimized, and optimize the parameters. Set the chessboard lattice side length of the deep-sea glass sponge cavity skeleton to L, and the diagonal support projection length to S;

[0015] (2a) Construct the geometric model to be optimized. The model formula is as follows:

[0016] Object=max(average(w in ))=max(average(|u i | 2 )) (1)

[0017] Object=min(average(u A )) (2)

[0018] Where Object – objective function;

[0019] average()——volume averaging function;

[0020] w in ——VAF cavity vorticity (s -1 );

[0021] u A——Flow velocity scalar at point A (m·s -1 )

[0022] u i ——Flow velocity vector (m·s -1 );

[0023] (2b) constructing a mathematical model to be optimized, and the mathematical model to be optimized is constructed and solved in OpenFOAM open source CFD software;

[0024] The governing equations for the dynamics of a two-phase fluid are:

[0025]

[0026]

[0027]

[0028] Where s – position (m);

[0029] t——time(s);

[0030] ——the probability density function of component k (i.e., water or oil) moving along the ith grid direction at position s and discrete time t;

[0031] u i ——Flow velocity vector (m·s -1 );

[0032] Δt(s)——time step;

[0033] f i k,eq ——local Maxwell equilibrium;

[0034] G k — the strength of the interaction between the two components;

[0035] ψ——pseudopotential function ψ k (s) = φ k (s)(1-v -φk(s) / φ0 );

[0036] w i ——The weight associated with the velocity direction of each grid;

[0037] φ k ——probability density of components;

[0038] τ k ——and fluid kinematic viscosity v k (s -1 ) related relaxation time;

[0039] c s ——Sound speed in the lattice frame (3 -0.5 )

[0040] The governing equation for single-phase flow simulation is:

[0041]

[0042] where g i (x, t) – probability density function of dissolved oil solution;

[0043] g i eq ——Local Maxwell equilibrium state of dissolved oil single-phase flow;

[0044] D——Diffusion coefficient of dissolved oil (m 2 ·s -1 );

[0045] (2c) Parameter optimization solution: Use the Covariance Matrix Adaptation Evolution Strategy algorithm method and formula 2-3 to optimize the structural parameters and obtain the optimal S / L value and L parameter;

[0046] Step 3: Output the skeleton-flagellar geometry model of the bionic vortex anchor filter to be verified:

[0047] In the Soildwork software, the skeleton-flagellum geometric model of the bionic eddy current anchor filter is constructed according to the optimized S / L and L parameters, overlapping and singular meshes are repaired, and a three-dimensional geometric model that can be 3D printed or digitally lathe processed is established;

[0048] Step 4: Simulation and verification of the fluid dynamics behavior of the bionic vortex anchor filter skeleton-flagellar structure

[0049] Import the skeleton-flagellum geometry model of the biomimetic vortex anchor filter to be verified in step 3 into the OpenFOAM software to establish a computable CFD model; and use this model to carry out the adsorbent interface mass transfer and skeleton fluid dynamics stability analysis at the target flow rate:

[0050] (4a) re-importing the biomimetic vortex anchor filter skeleton-flagellar structure to be verified obtained in step 3 into the OpenFOAM software, adjusting the model to a reasonable size according to the actual dimension, and establishing a verification model;

[0051] (4b) Input the adsorption rate and boundary parameters of the adsorption material, check the similarity between the verification model and the actual target conditions, and improve the verification model

[0052] (4c) Adjust the computational grid size near the bionic eddy current anchor filter skeleton to ensure that the single computational grid size is no larger than 0.005 mm;

[0053] (4d) Calculate the velocity distribution and concentration distribution at the maximum flow rate, and calculate the mass transfer coefficient Sh and the resistance coefficient Dc;

[0054]

[0055] Among them A int ——Mass transfer area of ​​adsorbent (cm 2 );

[0056] <> f ——Area average operator of fluid region;

[0057] <> w ——average operator of adsorbent surface area;

[0058] L——characteristic length, i.e., lattice size (cm);

[0059] F drag ——Total resistance acting on the oil capture device in the flow direction under steady state (N);

[0060] ρ inlet ——Density of the fluid at the inlet (g·cm -3 )

[0061] u inlet ——Fluid velocity at the inlet (cm·s -1 )

[0062] A——Cross-sectional area perpendicular to fluid flow (cm 2 )

[0063] C——Oil volume fraction (cm 2 )

[0064] D——Diffusion coefficient of dissolved oil (m 2· s -1 )

[0065] (4e) Determine whether the calculation results of the verification model meet the requirements that the cavity is full of small-sized vortices and the wake forms a static zone, and whether the mass transfer coefficient Sh is greater than 7.5 and the drag coefficient is less than 0.5; if so, conduct experimental verification; if not, adjust the initial values ​​of L and S / L in step (2c) and redesign.

[0066] The small size mentioned refers to the Kolmogorov microscale being less than 30 μm.

[0067] Furthermore, in the structural parameter optimization calculation process in step (2c), for soluble pollutants, the initial value of S / L is 0.2 and the initial value of L is 0.05 cm; for insoluble pollutants, the initial value of L is determined according to the size of the pollutants, with a minimum of 0.05 and a maximum of 1 cm, and the initial value of S / L is still 0.2.

[0068] Furthermore, in step 3, the bionic vortex anchor filter skeleton-flagellar geometry model is constructed in the Soildwork software according to the optimized S / L and L parameters, and the overlapping and singular meshes are repaired. The specific operations are as follows:

[0069] (3a) Based on the optimization parameters of (2c), the model is drawn in the Soildwork software, and the mesh is re-divided to solve the filter variables on a grid with a grid size no greater than 0.005m;

[0070] (3b) The optimization result of (3a) is filtered in the Soildwork software and output. The filtered variables are processed in the following way:

[0071]

[0072] Where γ is the filtering variable;

[0073] (3c) Based on the output results, a skeleton-flagellum geometric model of the three-dimensional bionic vortex anchor filter to be verified is established in the Soildwork software and exported in STL format.

[0074] The present invention discloses an application of a bionic vortex anchor filter for in-situ repair of natural water bodies under actual hydrodynamic conditions. The bionic vortex anchor filter is used to realize in-situ recovery of pollutants under actual hydrodynamic conditions.

[0075] In nature, the unique fluid functional structure of deep-sea glass sponges (such as E. aspergillum or Venus flower basket) has attracted the attention of the present invention and is closely related to the stable in-situ pollutant removal technology sought by the present invention. Unlike shallow-water sponges that live in food-rich waters, deep-sea sponges live in harsh deep-sea environments with high flow rates, shallow attachment surfaces, and scarce food, making prey extremely difficult. E. aspergillum achieves efficient, highly selective and highly stable filtering feeding by virtue of its unique mechanical structure. Specifically, E. aspergillum has a multi-layer skeleton-flagellar structure. When water flows through E. aspergillum, its skeleton guides external turbulence into three-dimensional streamlines that frequently collide, deflect, converge and separate. This frequent streamline interaction dissipates macroscopic turbulent energy into uniform small-sized slow vortices. This unique fluid mechanics behavior not only enhances the interfacial mass transfer of flagella, but also can form a stationary wake downstream, thereby reducing the resistance to the skeleton, giving E. aspergillum the ability to filter food efficiently and resist water scouring. This has enabled E. aspergillum to survive and reproduce in the deep sea environments of the Pacific Ocean and Antarctica at depths of 100 to 1,000 meters for nearly 100 million years.

[0076] In the process of oil capture, mass transfer and fluid dynamic stability are crucial, and this process is similar to the filter feeding mechanism of deep-sea glass sponges. Therefore, the present invention draws on the anatomical structure of E. aspergillum to design the skeleton structure, and the vortex anchored flow mode is realized under subcritical to supercritical flow conditions. In theory, this will: (1) enhance the interfacial mass transfer of the adsorbent; (2) increase the residence time of pollutants in the adsorbent working area; (3) dissipate turbulent kinetic energy and improve the fluid dynamic stability of the in-situ remediation equipment. Inspired by the skeleton characteristics and filter feeding behavior of E. aspergillum, the present invention develops a new type of vortex anchored filter (VAF) that can robustly perform in-situ remediation of natural water bodies under actual hydrodynamic conditions. This realizes a transformation of the in-situ remediation scheme of natural water bodies under actual hydrodynamic conditions from the traditional interception mode to the high-throughput drainage filtration mode. It breaks through the dilemma that traditional technologies cannot achieve a balance between high throughput, fluid dynamic stability and mass transfer capacity.

[0077] The present invention has the following beneficial effects:

[0078] The novel vortex anchor filter (VAF) of the present invention follows a top-down design approach, and uses a method of diversion rather than interception to process or recover pollutants in actual hydrodynamic conditions. It avoids the bypass and pollutant escape caused by traditional interception methods. At the same time, VAF learns and utilizes the method of biologically guided functional vortices for predation, induces small-sized vortices near the adsorbent to achieve enhanced mass transfer, and solves the problem of low mass transfer efficiency associated with high-throughput processing. In addition, the small-sized vortices near the adsorbent also have the effect of energy dissipation and transfer, converting environmental turbulent energy into swirling energy that is beneficial to mass transfer, and forming a stable static zone downstream of the VAF. This static zone avoids the pressure imbalance and high fluid resistance problems caused by structural bypass. Thereby achieving a balance between mass transfer, fluid dynamics stability, and passability.

[0079] It was found in actual tests that VAF can stably anchor external turbulent energy in the form of low-speed, small-sized eddies inside the VAF cavity. These eddies have a small Kolmogorov microscale (85μm), which allows more than 80% of the area in the cavity to have a coordination angle of less than 15°. Compared with the 30% area of ​​small coordination angle (<15°) in the traditional cylindrical interception mode, VAF increases the Sherwood number Sh of the water-adsorbent interface from 5.2 of the cylinder to 7.5. In addition, the dissipation of energy in the cavity forms a static zone downstream of the VAF. This static zone effectively reduces the drag coefficient of the VAF, making the VAF drag coefficient (0.3) only one-fifth of that of a cylindrical interceptor device of the same size (1.6). Under the effect of resistance reduction, the VAF can remain vertical under strong turbulence. Therefore, thanks to strong mass transfer, high fluid dynamics stability and high passability, the VAF can be used in subcritical, critical and supercritical conditions (Reynolds number Re=10 2 -10 5 ) Consistently achieves >97% capture of floating, underwater and emulsified oil. Achieves anchoring of eddies, energy, contaminants and the VAF itself in high flow environments.

[0080] On the other hand, VAF has the advantages of flexibility and convenience, and can demonstrate excellent adaptability, flexibility and sustainability in multiple practical scenarios. For example, VAF can be well integrated into mobile vehicles such as ships and vessels to achieve real-time and accurate positioning and cleaning of floating, underwater and emulsified pollutants. In addition, VAF can also be used as a counterweight for buoys to respond to emergency and unexpected natural water pollution incidents. Furthermore, with its unique hydrodynamic stability and high passability, VAF can also be used in an interconnected manner to build a long-term vertical barrier to prevent natural water pollution accidents at the source. This realizes a transformation of the in-situ remediation solution for natural water bodies under actual hydrodynamic conditions from the traditional interception mode to the high-throughput dredging and filtration mode. It breaks through the dilemma that traditional technologies cannot achieve a balance between high throughput, hydrodynamic stability and mass transfer capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] The drawings described herein are used to provide a further understanding of the present invention, constitute a part of the present application, and do not constitute an improper limitation of the present invention. In the drawings:

[0082] Figure 1 : Design and preparation flow chart of the in-situ repair bionic vortex anchor filter (VAF) of the present invention;

[0083] Figure 2 : The calculation domain and boundary condition annotation diagram in the design of the in-situ repair bionic eddy current anchor filter (VAF) of the present invention;

[0084] Figure 3 : The geometric model diagram of the skeleton structure and flagella structure of the in-situ repair bionic vortex anchor filter (VAF) of the present invention;

[0085] Figure 4 : A schematic diagram of the basic unit and dimension marking of the in-situ repair bionic eddy current anchor filter (VAF) chessboard lattice hollow cylinder of the present invention;

[0086] Figure 5 : Flow field distribution diagram of the in-situ repair bionic vortex anchor filter (VAF) of the present invention before and after optimization;

[0087] Figure 6 : Comparison diagram of oil capture effect of in-situ repair bionic vortex anchor filter (VAF) of the present invention;

[0088] Figure 7 : VAF structure fluid mechanics stability test diagram. DETAILED DESCRIPTION

[0089] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention more clearly understood, the spirit of the contents disclosed by the present invention will be described in detail below. After understanding the embodiments of the contents of the present invention, any technician in the relevant technical field can change and modify them according to the techniques taught by the contents of the present invention without departing from the spirit and scope of the contents of the present invention.

[0090] The exemplary embodiments of the present invention and the description thereof are used to explain the present invention but are not intended to limit the present invention.

[0091] Example 1: Design and application of VAF for in situ marine oil capture

[0092] Reference Figure 1 As shown, a VAF equipment design method for marine in-situ oil capture, the specific steps are as follows:

[0093] Step 1: Obtain the fluid environment and contamination range, and determine the adsorption material and structure size:

[0094] (1a) Obtain information on fluid density, viscosity, flow rate, corrosiveness, and suspended solids size; as well as information on the type, density, viscosity, particle size, and contamination range of the oil to be captured.

[0095] (1b) Select appropriate VAF skeleton materials according to water corrosivity information; determine adsorbent materials according to oil type and viscosity. In this example, the pollution incident is a marine oil spill accident, and the oil type is Si100. It has low corrosivity and no solid suspended particles. Therefore, in this example, the VAF skeleton material is stainless steel and the adsorbent material is hydrophobic melamine resin.

[0096] Step 2: Determine the CFD calculation parameters, calculation domain and boundary conditions:

[0097] Determine calculation parameters based on application scenario: Si100 density 850k·gm -3 , viscosity 0.001m 2 s, diffusion coefficient 7×10 -9 m 2 ·s -1 . Seawater density 1025 k·gm -3 , viscosity 001m 2 s. The oil pollution radius in the horizontal direction is 5m, and the oil pollution depth in the vertical direction is 0.2m. The maximum flow velocity (initial flow velocity and boundary flow velocity) is 0.5m / s, and the initial concentration is 1kg kg -1 .

[0098] The calculation domain is determined according to the pollution range. The width of the calculation domain is 2 times the pollution radius, the height is 10 times the oil pollution depth, and the length is 5 times the oil pollution radius. Therefore, the calculation domain is 10m wide, 2m high, and 25m long. Figure 2 shown.

[0099] The flow boundary conditions are set according to the actual flow conditions: the water flows along the length direction, the inlet is the incident boundary with a flow velocity of 0.5m / s, the outlet is the free outflow boundary with a pore pressure of zero, and the remaining boundaries are zero flux boundaries. The VAF skeleton and flagellum in the calculation domain are zero flux no-slip boundaries. The concentration boundary is set according to the distribution of oil pollution: the inlet is a constant volume fraction boundary with the same width and height as the pollution diameter, and the volume fraction is 1; the flagellar surface and the outlet are zero volume fraction boundaries; the remaining surfaces (including the calculation domain boundary and the skeleton boundary) are zero flux boundaries. This boundary condition setting assumes that the oil is instantly adsorbed on the flagellar surface. The boundary condition settings are as follows Figure 2 shown.

[0100] Step 3: Establish the VAF skeleton-flagellar geometry model to be optimized and determine the optimization parameters

[0101] Establish the three-dimensional VAF skeleton-flagella geometric model and mathematical model to be optimized and solve it. The steps are as follows:

[0102] (3a) Construct the geometric model to be optimized and determine the area to be optimized. The model to be optimized includes the VAF skeleton and flagella structure. Modeled after the periodic skeleton structure of E. aspergillum, the VAF skeleton consists of two parts: the inner part is a checkerboard lattice hollow cylinder and the outer part is an oblique spiral ridge ( Figure 3 ). The basic unit of the chessboard lattice hollow cylinder is as follows Figure 4 As shown, the lattice (square) width is L, and the diagonal brace projection length is S. The spiral ridge is connected by half 8 front bodies, and the side length is consistent with the lattice width, both L, and its position corresponds to the chessboard lattice one by one. The height of a single VAF is 16L (mm), and the diameter of a single VAF is 10L (mm). The length of the flagellar structure is consistent with the lattice width, both L, and the width is 0.05L. Therefore, the VAF skeleton structure can be controlled by S and L. When the lattice width L and the diagonal brace projection length S of the chessboard lattice are in a certain proportion, the chessboard lattice can regulate the horizontal flow pattern, and the spiral ridge can regulate the vertical flow pattern, thereby generating a uniform slow small-size vortex field inside the hollow cylinder and generating a static zone downstream of the skeleton. Therefore, the core problem of the design of this embodiment is to find the optimal value of the parameter S / L so that the average vorticity w inside it in Maximum, flow velocity u at point A downstream A Minimum( Figure 2 ). Point A is located on the symmetry axis of the skeleton along the flow direction, 25L downstream of the skeleton. The optimization objective function is:

[0103] Object=max(average(w in ))=max(average(|u i | 2 )) (1)

[0104] Object=min(average(u A )) (2)

[0105] Where Object – objective function;

[0106] average()——volume averaging function;

[0107] w in ——VAF cavity vorticity (s -1 );

[0108] u A ——Flow velocity scalar at point A (ms -1 )

[0109] u i ——Flow velocity vector (ms -1 )

[0110] (3b) Based on the geometry to be optimized obtained in step 2 and the computational domain and boundary conditions obtained in step 1, a mathematical model for structural optimization is constructed. The model is constructed and solved in the OpenFOAM open source CFD software with a grid type of D3Q19. The dynamics of the two-phase fluid is modeled by the lattice Boltzmann method, taking into account the conservation of momentum and the continuity equation. The interaction between the oil phase and the water phase is described by the Shan-Chen pseudopotential method. The conservation of momentum is described by the discrete Boltzmann equation with the Bhatnagar-Gross-Krook (BGK) collision operator. The coupled motion between the fluid and the flagellar adsorbent is handled by the immersed boundary algorithm (an existing algorithm). After adjusting the control equations, boundary conditions and computational parameters in the OpenFOAM software, preliminary calculations are performed to ensure the operability of the model.

[0111] The governing equations for the dynamics of a two-phase fluid are:

[0112]

[0113] Where s – position (m);

[0114] t——time(s);

[0115] ——the probability density function of component k (i.e., water or oil) moving along the ith grid direction at position s and discrete time t;

[0116] u i ——Flow velocity vector (ms -1 );

[0117] Δt(s)——time step;

[0118] ——local Maxwell equilibrium;

[0119] G k — the strength of the interaction between the two components;

[0120] ψ——pseudopotential function ψ k (s) = φ k (s)(1-v -φk(s) / φ0 );

[0121] w i ——The weight associated with the velocity direction of each grid;

[0122] φ k ——probability density of components;

[0123] τ k ——and fluid kinematic viscosity v k (s -1 ) related relaxation time;

[0124] c s ——Sound speed in the lattice frame (3 -0.5 )

[0125] For the single-phase flow simulation of dissolved oil problem, the governing equation is:

[0126]

[0127] where g i (x, t) – probability density function of dissolved oil solution;

[0128] g i eq ——Local Maxwell equilibrium state of dissolved oil single-phase flow;

[0129] D——Diffusion coefficient of dissolved oil (m 2 s -1 );

[0130] (3c) Parameter optimization solution: The Covariance Matrix Adaptation Evolution Strategy algorithm (CMA-ES) method is used to optimize the structural parameters of the optimization formula 1-2. During the calculation process, the initial value of S / L is 0.2, and the initial value of L is 0.2 cm. After the calculation is completed, the optimal S / L value is obtained, that is, the lattice width of the chessboard lattice hollow cylinder and the projection length of the diagonal brace. Thus, the optimized VAF skeleton-flagellar size L is obtained. The flow field distribution before and after optimization is shown in Figure 5 shown.

[0131] Step 4: Output the VAF skeleton-flagellar geometry model to be verified:

[0132] In the Soildwork software, the VAF skeleton-flagellum geometric model is constructed according to the S / L and L parameters optimized by 3C, the overlapping and singular meshes are repaired, and a three-dimensional geometric model that can be 3D printed or processed by digital lathe is established, as follows:

[0133] (4a) Based on the optimized parameter VAF skeleton-flagellar geometry model of (3c), the mesh is re-divided and the filtering variables are solved on a finer grid (grid size is no greater than 0.005m);

[0134] (4b) Filtering is performed based on the optimization results of the skeleton-flagellar model constructed by S and S / L, and the filtered variables are processed in the following manner:

[0135]

[0136] Where γ is the filter variable (design variable);

[0137] (4c) Based on the output of the filtering process, a three-dimensional VAF skeleton-flagellar geometric model to be verified was established in the Soildwork software ( Figure 3 ) and export to STL format.

[0138] Step 5, simulation verification of the fluid dynamics behavior of the VAF skeleton-flagellar structure. Import the VAF skeleton-flagellar geometry model to be verified generated in step 4 into the OpenFOAM software to establish a computable CFD model. This model is used to carry out the adsorbent interface mass transfer and skeleton fluid dynamics stability analysis at the target flow rate:

[0139] (5a) re-importing the VAF skeleton-flagellar structure to be verified obtained in step 4 into the OpenFOAM software, adjusting the model to a reasonable size according to the actual dimension, and establishing a verification model;

[0140] (5b) Input the material parameters and boundary parameters obtained in step 1 and step 2, check the similarity between the verification model and the actual target working conditions, and improve the verification model.

[0141] (5c) Adjust the grid size near the VAF skeleton to ensure that the maximum size of a single grid is no greater than 0.005 mm.

[0142] (5d) Calculate the velocity distribution and concentration distribution at the maximum flow rate, and calculate the mass transfer coefficient Sh and the resistance coefficient Dc.

[0143]

[0144] Among them A int——Mass transfer area of ​​adsorbent (cm 2 );

[0145] <> f ——Area average operator of fluid region;

[0146] <> w ——average operator of adsorbent surface area;

[0147] L——characteristic length, i.e., lattice size (cm);

[0148] F drag ——Total resistance acting on the oil capture device in the flow direction under steady state (N);

[0149] ρ inlet ——Density of the fluid at the inlet (g cm -3 )

[0150] u inlet ——Fluid velocity at the inlet (cm s -1 )

[0151] A——Cross-sectional area perpendicular to fluid flow (cm 2 )

[0152] C——Oil volume fraction (cm 2 )

[0153] D——Diffusion coefficient of dissolved oil (m 2 s -1 )

[0154] (5e) Determine whether the calculation results of the verification model meet the requirements that the cavity is full of small-sized slow vortices and the wake forms a static zone. And check whether the mass transfer coefficient Sh is greater than 7.5 and the drag coefficient is less than 0.5. If so, conduct experimental verification. If not, adjust the initial values ​​of L and S / L in step 2 and redesign until the above conditions are met after verification. After calculation, L is 5cm and S / L is 0.3.

[0155] Step 6, VAF skeleton-flagellar structure preparation and assembly, prepare the VAF device according to the verified VAF skeleton-flagellar geometric model size, the preparation method is as follows:

[0156] 6(a) The EOS M290 commercial 3D printer is equipped with a single-mode ytterbium-doped fiber laser with a maximum power of 400W. During the printing process, the laser power was set to 370W, the scanning speed was 650mm / s, the scanning pitch was 0.11mm, and the layer thickness was 30μm. To ensure that the oxygen content in the build chamber was less than 0.1%, it was controlled by filling with argon. After printing, the sample was separated from the build platform using wire electrospark cutting technology. Then, the sample was immersed in 95% alcohol solution for ultrasonic cleaning to remove residual powder.

[0157] 6(b) The hydrophobic melamine resin was woven into a linear structure with a length of 5 cm and a diameter of 0.25 cm using commercial textile equipment. The woven hydrophobic melamine resin was bound to each node of the VAF skeleton.

[0158] Performance test:

[0159] (1) Oil capture capacity test. Figure 6 As shown, the VAF device constructed in this embodiment can maintain an oil capture efficiency greater than 97% under various Re conditions, thus overcoming the difficulty that the conventional technology cannot effectively implement oil capture under high Re conditions.

[0160] (2) Fluid mechanics stability test. Figure 7 As shown, the VAF device constructed in this embodiment can maintain a stable vertical state under various Re conditions, breaking through the oil escape problem caused by the swing or overturning of traditional oil interception measures with water.

[0161] The present invention is inspired by the efficient and stable filtering behavior of E. aspergillum in low nutrient concentration, high flow rate and shallow anchoring environment, and adopts the E. aspergillum skeleton structure with eddy anchoring ability and the flagella-type adsorbent with high specific surface area to construct a bionic eddy anchor filter (VAF). The measured results show that VAF can anchor eddy currents, energy, pollutants and itself. It can maintain a stable vertical state and efficient internal mass transfer capacity when the flow rate reaches the critical state and supercritical state, and maintain an oil capture capacity of not less than 97%. This is attributed to the fact that VAF can convert external turbulent kinetic energy into abundant small-sized slow eddy energy inside, which not only improves the mass transfer and residence time in the cavity, but also creates a downstream static zone. Thereby achieving a balance between mass transfer, passability and fluid mechanics stability. It also realizes a transformation of the in-situ remediation scheme of natural water bodies under actual hydrodynamic conditions from the traditional interception mode to the high-throughput dredging filtration mode. The present invention is not limited to oil capture tasks, but can also use other active materials as flagellar substrates to obtain an in-situ high mass transfer reactor under actual hydrodynamic conditions that meets the needs of fields such as energy, environment and chemical industry.

Claims

1. A bionic vortex anchor filter for in-situ repair of natural water bodies under actual hydrodynamic conditions, characterized in that It is composed of a deep-sea glass sponge cavity skeleton and a flagella-type adsorbent.

2. A bionic vortex anchor filter for in-situ repair of natural water bodies under actual hydrodynamic conditions according to claim 1, characterized in that The deep-sea glass sponge cavity skeleton is a hollow cylindrical structure, the outside of the hollow cylindrical structure is provided with spiral ridges, and the flagella-type adsorbent is fixed on the periphery of the deep-sea glass sponge cavity skeleton.

3. The bionic vortex anchor filter for in-situ repair of natural water bodies under actual hydrodynamic conditions according to claim 1 is characterized in that The spiral ridge is formed by connecting "corner-cut wedges", which are wedge-shaped bodies formed by cutting off two corners of a cube along a diagonal line; the side length of the original cube of the "corner-cut wedge" without corner cutting is L.

4. A bionic vortex anchor filter for in-situ repair of natural water bodies under actual hydrodynamic conditions according to claim 1, 2 or 3, characterized in that The deep-sea glass sponge cavity skeleton is a hollow cylindrical structure of a grid composed of a checkerboard lattice as a basic unit. The checkerboard lattice is composed of an "open square" with four-corner diagonal braces and a "closed square" with internal cross diagonal braces. The two types of squares are arranged in a staggered manner.

5. A bionic vortex anchor filter for in-situ repair of natural water bodies under actual hydrodynamic conditions according to claim 4, characterized in that The side lengths of the "open grid" and the "closed grid" are both L, and the right-angled side length of the triangle formed by the diagonal support in the "open grid" is S; the size of the in-situ repair bionic eddy current anchor filter is determined based on the S / L and L values.

6. The bionic vortex anchor filter for in-situ repair of natural water bodies under actual hydrodynamic conditions according to claim 1, characterized in that The length of the flagella of the flagella-type adsorbent and the length of the oblique spiral ridge are the same as the side length L of the "open square" and the "closed square", and the width of the flagella of the flagella-type adsorbent is 0.05L; the height of the bionic vortex anchor filter is 16L and the diameter is 10L.

7. A design method for a bionic vortex anchor filter for in-situ repair of natural water bodies under actual hydrodynamic conditions as claimed in claim 1, characterized in that The design method is as follows: Step 1: Obtain the fluid environment and contamination range, and determine the adsorption material and structure size: (1a) Obtain information on fluid density, viscosity, flow rate, corrosiveness, and suspended solids size; as well as information on the type, density, viscosity, particle size, and contamination range of pollutants to be captured; (1b) selecting appropriate bionic eddy current anchor filter skeleton material according to water corrosivity information; Step 2, establish the geometric model and mathematical model of the bionic eddy current anchor filter skeleton-flagellum to be optimized, and optimize the parameters. Set the chessboard lattice side length of the deep-sea glass sponge cavity skeleton to L, and the diagonal support projection length to S; (2a) Construct the geometric model to be optimized. The model formula is as follows: Object=max(average(w in ))=max(average(|u i | 2 )) (1) Object=min(average(u A )) (2) Where Object – objective function; average()——volume averaging function; w in ——Vorticity in VAF cavity (s -1 ); u A ——Flow velocity scalar at point A (m·s -1 ) u i ——Flow velocity vector (m·s -1 ); (2b) constructing a mathematical model to be optimized, and the mathematical model to be optimized is constructed and solved in OpenFOAM open source CFD software; The governing equations for the dynamics of a two-phase fluid are: Where s – position (m); t——time(s); ——the probability density function of component k (i.e., water or oil) moving along the ith grid direction at position s and discrete time t; u i ——Velocity vector (m·s -1 ); Δt(s)——time step; ——Local Maxwell equilibrium; G k — the strength of the interaction between the two components; ψ——pseudopotential function ψ k (s) = φ k (s)(1-v -φk(s) / φ0 ); w i ——The weight associated with the velocity direction of each grid; φ k ——probability density of components; τ k ——and fluid kinematic viscosity v k (s -1 ) related relaxation time; c s ——Sound speed in the lattice frame (3 -0.5 ) The governing equation for single-phase flow simulation is: where g i (x, t) – probability density function of dissolved oil solution; g i eq ——Local Maxwell equilibrium state of dissolved oil single-phase flow; D——Diffusion coefficient of dissolved oil (m 2 ·s -1 ); (2c) Parameter optimization solution: Use the Covariance Matrix Adaptation Evolution Strategy algorithm method and formula 2-3 to optimize the structural parameters and obtain the optimal S / L value and L parameter; Step 3: Output the skeleton-flagellar geometry model of the bionic vortex anchor filter to be verified: In the Soildwork software, the skeleton-flagellum geometric model of the bionic eddy current anchor filter is constructed according to the optimized S / L and L parameters, overlapping and singular meshes are repaired, and a three-dimensional geometric model that can be 3D printed or digitally lathe processed is established; Step 4: Simulation and verification of the fluid dynamics behavior of the bionic vortex anchor filter skeleton-flagellar structure Import the skeleton-flagellum geometry model of the biomimetic vortex anchor filter to be verified in step 3 into the OpenFOAM software to establish a computable CFD model; and use this model to carry out the adsorbent interface mass transfer and skeleton fluid dynamics stability analysis at the target flow rate: (4a) re-importing the biomimetic vortex anchor filter skeleton-flagellar structure to be verified obtained in step 3 into the OpenFOAM software, adjusting the model to a reasonable size according to the actual dimension, and establishing a verification model; (4b) Input the adsorption rate and boundary parameters of the adsorption material, check the similarity between the verification model and the actual target conditions, and improve the verification model (4c) Adjust the computational grid size near the bionic eddy current anchor filter skeleton to ensure that the single computational grid size is no larger than 0.005 mm; (4d) Calculate the velocity distribution and concentration distribution at the maximum flow rate, and calculate the mass transfer coefficient Sh and the resistance coefficient Dc; Among them A int ——Mass transfer area of ​​adsorbent (cm 2 ); <> f ——Area average operator of fluid region; <> w ——average operator of adsorbent surface area; L——characteristic length, i.e., lattice size (cm); F drag ——Total resistance acting on the oil capture device in the flow direction under steady state (N); ρ inlet ——Density of the fluid at the inlet (g·cm -3 ) u inlet ——Fluid velocity at the inlet (cm·s -1 ) A——Cross-sectional area perpendicular to fluid flow (cm 2 ) C——Oil volume fraction (cm 2 ) D——Diffusion coefficient of dissolved oil (m 2 ·s -1 ) (4e) Determine whether the calculation results of the verification model meet the requirements that the cavity is full of small-sized vortices and the wake forms a static zone, and whether the mass transfer coefficient Sh is greater than 7.5 and the drag coefficient is less than 0.5; if so, conduct experimental verification; if not, adjust the initial values ​​of L and S / L in step (2c) and redesign.

8. The design method of a bionic vortex anchor filter for in-situ repair of natural water bodies under actual hydrodynamic conditions according to claim 7 is characterized in that During the structural parameter optimization calculation process in step (2c), for soluble pollutants, the initial value of S / L is 0.2 and the initial value of L is 0.05 cm; for insoluble pollutants, the initial value of L is determined according to the size of the pollutants, with a minimum of 0.05 and a maximum of 1 cm, and the initial value of S / L is still 0.

2.

9. The design method of a bionic vortex anchor filter for in-situ repair of natural water bodies under actual hydrodynamic conditions according to claim 7 is characterized in that Step 3: In Soildwork software, build the bionic vortex anchor filter skeleton-flagellar geometry model according to the optimized S / L and L parameters, and repair the overlapping and singular meshes. The specific operations are as follows: (3a) Based on the optimization parameters of (2c), the model is drawn in the Soildwork software, and the mesh is re-divided to solve the filter variables on a grid with a grid size no greater than 0.005m; (3b) The optimization result of (3a) is filtered in the Soildwork software and output. The filtered variables are processed in the following way: Where γ is the filtering variable; (3c) Based on the output results, a skeleton-flagellum geometric model of the three-dimensional bionic vortex anchor filter to be verified is established in the Soildwork software and exported in STL format.

10. The use of a bionic vortex anchor filter for in-situ repair of natural water bodies under actual hydrodynamic conditions as claimed in claim 1, characterized in that The bionic vortex anchored filter is used to achieve in-situ recovery of pollutants under actual hydrodynamic conditions.

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