Nozzle design method

Abstract

This document provides a method for designing nozzles. [Solution] This is a nozzle design method suitable for designing a nozzle for surface modification of particulate matter, which includes sequentially connected shrinkage stage, throat stage, and diffusion stage. Computational fluid dynamics-discrete element method (CFD-DEM) software is used to simulate at least one nozzle size group over a range of particulate matter velocities to obtain the first to third coefficient ranges and a constant range for the nozzle size design equation, where V = a*X + b*Y + c*Z + d, where V is the particulate matter velocity, a, b, and c are the first to third coefficients, respectively, d is a constant, and X, Y, and Z are the maximum flow path diameters of the shrinkage stage, throat stage, and diffusion stage, respectively. Using the CFD-DEM software, calculations are performed using the nozzle size design equation with the first to third coefficient ranges, the constant range, and the target velocity to obtain the calculated nozzle size group.

Description

Technical Field

[0001] The present disclosure relates to a microparticle surface modification technique, and particularly to a nozzle design method.

Background Art

[0002] The microparticle surface modification technique can improve the strength and hardness of the surface of a workpiece, improve the wear resistance and lubricity of the surface of the workpiece, and further extend the service life of the workpiece by the collision of microparticles with the surface of the workpiece. The injection speed of the microparticles affects the unevenness of the surface of the workpiece, and thus affects the surface modification effect of the workpiece.

Summary of the Invention

Problems to be Solved by the Invention

[0003] According to related technical documents, the size design of the nozzle significantly affects the injection speed of the microparticles. Therefore, the size design of the nozzle for microparticle surface modification has already become a quite important part in the development of the microparticle surface modification technique.

Means for Solving the Problems

[0004] One object of the present disclosure is to provide a nozzle design method that uses the coupled simulation technique of computational fluid dynamics - discrete element method (CFD-DEM) software to simulate the interaction between airflow and microparticles in different geometric parameters of the nozzle, and obtain a nozzle size design equation. Since the nozzle size can be quickly and repeatedly designed according to the nozzle size design equation, the time cost of experiments and adjustments during nozzle design can be reduced, and the efficiency of the nozzle in industrial applications can be improved. In addition, this method can accurately predict the microparticle velocity in combinations of different nozzle diameters, and can greatly improve the efficiency and accuracy of nozzle design.

[0005] Another object of this disclosure is to provide a nozzle design method that can accommodate different operating needs and material properties and ensure the optimal spraying effect of the nozzle, by allowing the nozzle size to be adjusted instantly according to the particle velocity.

[0006] In accordance with the above-mentioned objectives of this disclosure, we propose a nozzle design method suitable for designing a nozzle for surface modification of particulate matter, which includes sequentially connected shrinkage stage, throat stage, and diffusion stage. In this method, computational fluid dynamics-discrete element method software is used to simulate at least one nozzle size group over a range of particulate matter velocities to obtain a first coefficient range, a second coefficient range, a third coefficient range, and a constant range for the nozzle size design equation. Each nozzle size group includes the maximum flow diameter of the shrinkage stage, the maximum flow diameter of the throat stage, and the maximum flow diameter of the diffusion stage. The nozzle size design equation is V = a*X + b*Y + c*Z + d, where V represents the particulate matter velocity, a, b, and c represent the first, second, and third coefficients, respectively, d represents a constant, X represents the maximum flow diameter of the shrinkage stage, Y represents the maximum flow diameter of the throat stage, and Z represents the maximum flow diameter of the diffusion stage. Using computational fluid dynamics—discrete element method software, calculations are performed using the nozzle size design equation with a first coefficient range, a second coefficient range, a third coefficient range, and a constant range, as well as the target velocity, to obtain a set of calculated nozzle sizes.

[0007] According to one embodiment of the present disclosure, the particle velocity range is a range from a predetermined particle velocity minus -5% of this predetermined particle velocity to a predetermined particle velocity plus +5% of this predetermined particle velocity.

[0008] According to one embodiment of the present disclosure, the simulation of at least one set of nozzle sizes in a particle velocity range using computational fluid dynamics-discrete element method software includes the use of an iterative solution method for linear equations.

[0009] According to one embodiment of the present disclosure, the at least one nozzle size group includes a first nozzle size group. In the first nozzle size group, the maximum flow path diameter of the contraction stage is 14 mm, the maximum flow path diameter of the throat stage is 7 mm, and the maximum flow path diameter of the diffusion stage is 9 mm.

[0010] According to one embodiment of the present disclosure, the at least one nozzle size group further includes a second nozzle size group. In the second nozzle size group, the maximum flow path diameter of the contraction stage is 11 mm, the maximum flow path diameter of the throat stage is 4 mm, and the maximum flow path diameter of the diffusion stage is 6 mm.

[0011] According to one embodiment of the present disclosure, the at least one nozzle size group further includes a third nozzle size group. In the third nozzle size group, the maximum flow path diameter of the contraction stage is 17 mm, the maximum flow path diameter of the throat stage is 10 mm, and the maximum flow path diameter of the diffusion stage is 12 mm.

[0012] According to one embodiment of the present disclosure, the first coefficient range is 20 to 100, the second coefficient range is -100 to 200, the third coefficient range is -1 to 20, and the constant range is 400 to 1300.

[0013] According to one embodiment of the present disclosure, the nozzle design method further includes obtaining a set of calculated nozzle sizes, then simulating the set of calculated nozzle sizes using computational fluid dynamics-discrete element method software to obtain a simulation speed in which the error with respect to the target speed is 5% or less.

[0014] According to one embodiment of the present disclosure, when performing calculations using computational fluid dynamics-discrete element method software for a nozzle size design equation with a first coefficient range, a second coefficient range, a third coefficient range, and a constant range, as well as a target velocity, the method includes using an iterative method of solving linear equations.

[0015] According to one embodiment of the present disclosure, the length of the shrinkage stage of the nozzle for surface modification of fine particles is 12 mm, the length of the throat stage is 19 mm, and the length of the diffusion stage is 5 mm. [Brief explanation of the drawing]

[0016] The aspects of this disclosure will be better understood from the detailed description below in relation to the attached drawings. It should be noted that, based on standard industry practice, each feature is not depicted proportionally. In fact, to clarify the discussion, the size of each feature can be arbitrarily increased or decreased. [Figure 1] This is a schematic side view showing a nozzle according to one embodiment of the present disclosure. [Figure 2] A schematic flow diagram illustrating a nozzle design method according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0017] The embodiments of this disclosure are described in detail below. However, it should be understood that the embodiments provide many applicable concepts that can be implemented in various specific content. The embodiments discussed and disclosed are for illustrative purposes only and are not intended to limit the scope of this disclosure. All embodiments of this disclosure disclose various different features, which may be implemented individually or in combination as needed.

[0018] Furthermore, the terms "first," "second," etc., used herein do not specifically indicate order or rank, but are used solely to distinguish elements or operations described using the same technical terminology.

[0019] The spatial relationships between two elements described in this disclosure apply not only to orientations shown in the drawings but also to orientations not shown in the drawings, such as inverted orientations. Furthermore, the terms “connection,” “electrical connection,” or similar terms used in this disclosure between two components are not limited to direct or electrical connections between the two components, but may also include indirect or electrical connections as appropriate.

[0020] Please refer to Figure 1, a schematic side view showing a nozzle 100 according to one embodiment of the present disclosure. The nozzle 100 is a nozzle for surface modification of fine particles. The nozzle 100 can modify the surface of a workpiece by spraying fine particles onto the workpiece surface and utilizing the impact of these fine particles on the workpiece surface. The nozzle 100 may mainly include a shrinkage stage 110, a throat stage 120, and a diffusion stage 130. The shrinkage stage 110, the throat stage 120, and the diffusion stage 130 are sequentially connected to form the nozzle 100. Specifically, the throat stage 120 is sandwiched between the shrinkage stage 110 and the diffusion stage 130 by joining its opposing ends to one end of the shrinkage stage 110 and one end of the diffusion stage 130, respectively.

[0021] The gas and fine particles enter the nozzle 100 from the contraction stage 110, pass through the throat stage 120 along the flow direction FD of the gas and fine particles, and are ejected out of the nozzle 100 from the diffusion stage 130. In some embodiments, along the flow direction FD, the flow path of the contraction stage 110 gradually narrows and the flow path of the diffusion stage 130 gradually widens. In this embodiment, the cross-sectional shapes of the flow paths of the contraction stage 110, throat stage 120, and diffusion stage 130 are circular. The contraction stage 110 has a maximum flow path diameter A, the throat stage 120 has a maximum flow path diameter B, and the diffusion stage 130 has a maximum flow path diameter C. The contraction stage 110 also has a length L1, the throat stage 120 has a length L2, and the diffusion stage 130 has a length L3.

[0022] The size design of the contraction stage 110 is crucial for controlling the amount of gas drawn into the nozzle 100. The throat stage 120 is a critical part for controlling the gas flow velocity and is extremely important for increasing the gas velocity; its diameter and length must match the size design of the contraction stage 110 and the diffusion stage 130. The diffusion stage 130 can reduce the gas pressure in order to stabilize and improve the injection kinetic energy of the fine particles. In terms of design, it is necessary to consider that the fluid passes smoothly through the diffusion stage 130 to avoid turbulence. By optimizing the geometry of the nozzle 100 and precisely controlling the length and diameter of each stage of the nozzle 100, stable acceleration of the airflow in the nozzle 100 can be ensured, turbulence can be avoided, and the injection kinetic energy of the fine particles can be further improved.

[0023] Referring to FIGS. 1 and 2 simultaneously, FIG. 2 is a flow schematic diagram showing a nozzle design method 200 according to an embodiment of the present disclosure. The nozzle design method 200 can be used to design the above-mentioned nozzle 100 for surface modification of fine particles. In this embodiment, the nozzle design method 200 is performed in a situation where the length L1 of the contraction section 110, the length L2 of the throat section 120, and the length L3 of the diffusion section 130 of the nozzle 100 are fixed. In some embodiments, the length L1 of the contraction section 110 is 12 mm, the length L2 of the throat section 120 is 19 mm, and the length L3 of the diffusion section 130 is 5 mm.

[0024] When designing the nozzle 100 using the nozzle design method 200, first, a step 210 of simulating at least one group of nozzle sizes may be performed using computational fluid dynamics - discrete element method (CFD-DEM) software. The computational fluid dynamics - discrete element method software can perform a solid-gas two-phase flow simulation and simulate the movement trajectories of the airflow and fine particles. Each group of nozzle sizes includes the maximum flow path diameter A of the contraction section 110, the maximum flow path diameter B of the throat section 120, and the maximum flow path diameter C of the diffusion section 130. When performing step 210, each group of nozzle sizes is simulated within the fine particle velocity range. For example, the range of the fine particle velocity may be from a value obtained by subtracting 5% of the selected fine particle velocity from the selected fine particle velocity to a value obtained by adding 5% of the selected fine particle velocity to the selected fine particle velocity. The above-mentioned selected fine particle velocity may be 200 mm / s to 1400 mm / s. However, the range of this fine particle velocity may be any plurality of velocities within 200 mm / s to 1400 mm / s, but the present disclosure is not limited thereto.

[0025] When simulating at least one group of nozzle sizes using computational fluid dynamics - discrete element method software, the first coefficient range, the second coefficient range, the third coefficient range, and the constant range of the nozzle size design equation can be obtained. The nozzle size design equation is V = a*X + b*Y + c*Z + d. Here, V represents the particle velocity, a, b, and c represent the first coefficient, the second coefficient, and the third coefficient respectively, d represents the constant, X represents the maximum channel diameter of the contraction section, Y represents the maximum channel diameter of the throat section, and Z represents the maximum channel diameter of the diffusion section. The first coefficient range, the second coefficient range, the third coefficient range, and the constant range are the numerical ranges of the first coefficient, the second coefficient, the third coefficient, and the constant respectively. In some embodiments, when simulating the nozzle size group using computational fluid dynamics - discrete element method software, an iterative solution method of a linear equation is used.

[0026] In some embodiments, the above at least one group of nozzle sizes includes a first group of nozzle sizes. In the first group of nozzle sizes, the maximum channel diameter A of the contraction section 110 is 14 mm, the maximum channel diameter B of the throat section 120 is 7 mm, and the maximum channel diameter C of the diffusion section 130 is 9 mm. In another embodiment, the above at least one group of nozzle sizes further includes a second group of nozzle sizes in addition to the first group of nozzle sizes. In the second group of nozzle sizes, the maximum channel diameter A of the contraction section 110 is 11 mm, the maximum channel diameter B of the throat section 120 is 4 mm, and the maximum channel diameter C of the diffusion section 130 is 6 mm. In yet another embodiment, the above at least one group of nozzle sizes further includes a third group of nozzle sizes. In the third group of nozzle sizes, the maximum channel diameter A of the contraction section 110 is 17 mm, the maximum channel diameter B of the throat section 120 is 10 mm, and the maximum channel diameter C of the diffusion section 130 is 12 mm.

[0027] In the embodiment for simulating the above first to third nozzle size groups, the first coefficient range of the nozzle size design equation obtained by simulation using computational fluid dynamics-discrete element method software is 20 to 100, the second coefficient range is -100 to 200, the third coefficient range is -1 to 20, and the constant range is 400 to 1300. In this case, the nozzle size design equation is V = (20 to 100)*X + (-100 to 200)*Y + (-1 to 20)*Z + (400 to 1300).

[0028] It should be noted that the first coefficient range, second coefficient range, third coefficient range, and constant range of the nozzle size design equations obtained by simulating different nozzle size groups using computational fluid dynamics - discrete element method software may differ from those in the above examples. Computational fluid dynamics - discrete element method software can improve the accuracy of the first coefficient range, second coefficient range, third coefficient range, and constant range of the nozzle size design equations when simulating a larger number of nozzle size groups.

[0029] After obtaining the first coefficient range, second coefficient range, third coefficient range, and constant range of the nozzle size design equation, step 220 may be performed to obtain a group of calculated nozzle sizes by performing calculations using computational fluid dynamics-discrete element method software with the first coefficient range, second coefficient range, third coefficient range, and constant range, as well as the target velocity, in relation to the nozzle size design equation. Specifically, the computational fluid dynamics-discrete element method software can substitute this target velocity into the nozzle size design equation V=(20~100)*X+(-100~200)*Y+(-1~20)*Z+(400~1300) and perform a simulation to obtain a group of calculated nozzle sizes. This group of calculated nozzle sizes includes the calculated maximum flow diameter of the contraction stage, the maximum flow diameter of the throat stage, and the maximum flow diameter of the diffusion stage. That is, this simulation calculation can determine X, Y, and Z in the nozzle size design equation. In some embodiments, this simulation calculation includes using an iterative method of solving linear equations.

[0030] In response to the requirements for surface modification of particulate matter, a target velocity at which the particulate matter is ejected from the nozzle 100 can be obtained. For example, the requirements for surface modification of particulate matter can include the coverage of the particulate matter, surface roughness, and mechanical properties such as surface hardness, tensile strength, and residual stress. At this target velocity, computational fluid dynamics-discrete element method software can simulate and calculate the maximum flow path diameters of the contraction stage 110, throat stage 120, and diffusion stage 130 of the nozzle 100 corresponding to this target velocity using the nozzle size design equation V=(20~100)*X+(-100~200)*Y+(-1~20)*Z+(400~1300).

[0031] After calculating the maximum flow diameters for the contraction stage, throat stage, and diffusion stage in step 220, the surface coverage of the microparticles ejected from nozzle 100 can be simulated using computational fluid dynamics-discrete element method software. Furthermore, actual microparticle injection experiments can be conducted using the designed nozzle 100. This verifies the design effectiveness of nozzle 100, including surface coverage, surface roughness, and mechanical properties such as hardness, tensile strength, and surface residual stress. Additionally, simulation parameters can be adjusted and optimized based on the verification results to improve the accuracy of the design results.

[0032] The nozzle design method 200 of this embodiment uses coupled simulation techniques of computational fluid dynamics-discrete element method software to simulate the interaction between airflow and particles under different geometric parameters of the nozzle 100, thereby obtaining a nozzle size design equation. The nozzle size design equation allows for rapid iterative design of the nozzle size, reducing the time cost of experimentation and adjustment during the design of the nozzle 100, and improving the efficiency of the nozzle 100 in industrial applications. Furthermore, this method can accurately predict particle velocity for different nozzle diameter combinations, significantly increasing the efficiency and accuracy of nozzle 100 design. Additionally, the nozzle design method 200 allows for immediate adjustment of the nozzle size 100 according to particle velocity, accommodating different operational needs and material properties, and ensuring the optimal injection effect of the nozzle 100.

[0033] Embodiments of this disclosure predict and optimize the design of the nozzle 100 based on a method integrating numerical simulation and experimental verification, enabling the fine particles to achieve an optimal injection effect. Therefore, the coverage range, surface roughness, and mechanical properties of the fine particle surface modification can be improved. By optimizing the size of the nozzle 100, the gas pressure limit of the table can be overcome, enabling higher airflow velocity and fine particle acceleration effect at lower gas pressure parameters. Thus, the fine particle velocity can be effectively increased without increasing gas pressure or energy consumption, strengthening the impact force of the fine particle injection, shortening the surface modification time for strengthening and polishing, and further improving processing efficiency. Furthermore, a faster fine particle injection velocity means that processing can be completed in a shorter time, reducing energy consumption during equipment operation and further improving energy utilization. Optimized design of the nozzle 100 velocity improves the fine particle processing effect, achieving higher coverage and better surface treatment effects, thereby significantly improving the durability and performance of the workpiece surface.

[0034] While the present disclosure is disclosed in embodiments as described above, these embodiments are not intended to limit the present disclosure. Any person skilled in the art could make various changes and modifications without departing from the spirit and scope of the present disclosure, and the scope of protection of the present disclosure should be based on the claims appended thereto. [Explanation of Symbols]

[0035] 100: Nozzle 110: Contraction stage 120: Throat stage 130: Diffusion stage 200: Nozzle Design Method 210, 220: Process A, B, C: Maximum diameter of the flow path FD: Flow direction L1, L2, L3: Length

Claims

1. A nozzle design method suitable for designing a nozzle for surface modification of particulate matter, which includes sequentially connected shrinkage stage, throat stage, and diffusion stage, Using computational fluid dynamics-discrete element method (CFD-DEM) software, at least one nozzle size group was simulated within a particle velocity range to obtain the first coefficient range, second coefficient range, third coefficient range, and constant range of the nozzle size design equation, each of the at least one nozzle size group including the maximum flow path diameter of the contraction stage, the maximum flow path diameter of the throat stage, and the maximum flow path diameter of the diffusion stage, and the nozzle size design equation is V = a*X + b*Y + c*Z + d, where V represents the particle velocity, a, b, and c represent the first coefficient, second coefficient, and third coefficient, respectively, d represents a constant, X represents the maximum flow path diameter of the contraction stage, Y represents the maximum flow path diameter of the throat stage, and Z represents the maximum flow path diameter of the diffusion stage. Using the computational fluid dynamics-discrete element method software, calculations are performed using the nozzle size design equation with the first coefficient range, second coefficient range, third coefficient range, and constant range, as well as the target velocity, to obtain a set of calculated nozzle sizes. A method for designing a nozzle that includes [a specific feature / etc.].

2. The nozzle design method according to claim 1, wherein the particle velocity range is a range from a predetermined particle velocity minus -5% of the predetermined particle velocity to a predetermined particle velocity plus +5% of the predetermined particle velocity.

3. The nozzle design method according to claim 1, comprising using an iterative solution method for linear equations when simulating the at least one nozzle size group in the particle velocity range using the computational fluid dynamics-discrete element method software.

4. The nozzle design method according to claim 1, wherein the at least one nozzle size group includes a first nozzle size group, and in the first nozzle size group, the maximum diameter of the flow path in the contraction stage is 14 mm, the maximum diameter of the flow path in the throat stage is 7 mm, and the maximum diameter of the flow path in the diffusion stage is 9 mm.

5. The nozzle design method according to claim 4, wherein the at least one nozzle size group further includes a second nozzle size group, and in the second nozzle size group, the maximum diameter of the flow path of the contraction stage is 11 mm, the maximum diameter of the flow path of the throat stage is 4 mm, and the maximum diameter of the flow path of the diffusion stage is 6 mm.

6. The nozzle design method according to claim 5, wherein the at least one nozzle size group further includes a third nozzle size group, and in the third nozzle size group, the maximum diameter of the flow path of the contraction stage is 17 mm, the maximum diameter of the flow path of the throat stage is 10 mm, and the maximum diameter of the flow path of the diffusion stage is 12 mm.

7. The nozzle design method according to claim 6, wherein the first coefficient range is 20 to 100, the second coefficient range is -100 to 200, the third coefficient range is -1 to 20, and the constant range is 400 to 1300.

8. The nozzle design method according to claim 1, further comprising obtaining the calculated nozzle size group, simulating the calculated nozzle size group using the computational fluid dynamics-discrete element method software, and obtaining a simulation speed with an error of 5% or less from the target speed.

9. The nozzle design method according to claim 1, comprising using the computational fluid dynamics-discrete element method software to perform calculations using the nozzle size design equation with respect to the first coefficient range, the second coefficient range, the third coefficient range, the constant range, and the target velocity, and further comprising using an iterative method for solving linear equations.

10. The nozzle design method according to claim 1, wherein the length of the shrinkage stage of the nozzle for surface modification of fine particles is 12 mm, the length of the throat stage is 19 mm, and the length of the diffusion stage is 5 mm.

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