目的 建立高压无气喷涂雾化与表面成膜模型,研究不同工艺参数下的腻子雾化效果以及轨道客车白车身复杂形面的喷涂表面成膜特性,为自动喷涂轨迹规划提供理论指导,以提高轨道客车白车身自动喷涂的效率与涂层质量。方法 在Fluent中构建VOF-DPM耦合多尺度模型,引入网格自适应与VOF-to-DPM转换机制;先以VOF解析初次破碎并结合高速摄影标定扇面形貌与粒径分布,再将转换区划分为多个长方体采样区提取颗粒数量、粒径与质量流率,基于分区数据构建多雾化器DPM模型,模拟不同轨迹规划策略下不同特征形面的成膜,并兼顾计算成本与精度。结果 模拟雾化形貌与高速摄影实验数据高度吻合;增高压力、降低黏度可显著扩大喷雾扇幅、加速雾化并细化粒径。在喷涂压力25 MPa、腻子黏度0.32 kg/(m·s)的高压低黏工艺参数下,喷雾扇面完全展开并使破碎前移,喷雾成膜在各形面沿扇面展开方向呈“两侧高-中间低”的双峰分布;距平面300 mm喷涂时,轨迹间隔200 mm兼顾最大涂覆范围与膜厚均匀性,间隔过小致过度重叠、过大致两道分离;V形面宜沿母线移动喷涂,而曲面沿准线喷涂更优。结论 构建的高压无气喷涂雾化与表面成膜模型能够准确预测无气喷涂腻子的雾化与表面成膜过程,工艺参数对雾化效果起决定性作用,而喷涂轨迹策略则显著影响膜厚分布与均匀性。
Abstract
High-pressure airless spraying technology is a key process in vehicle coating and is widely used in coating the body-in-white of rail coaches. However, the surfaces of large shells such as rail coaches are still predominantly coated manually, making coating quality difficult to control. Therefore, automated spraying technology has become a research focus. In automated spraying, it is essential to define process parameters and develop trajectory-planning strategies. To establish a relationship between process parameters and trajectory-planning strategies and achieve efficient, high-quality automated spraying, it is necessary to elucidate the effect of spraying process parameters on the atomization mechanism and the effect of trajectory-planning strategies on surface film formation. Accordingly, in the commercial CFD software Fluent, a VOF-DPM coupled atomization and surface film formation model is established for high-pressure airless putty spraying on complex surfaces of the rail coach body-in-white based on the Volume of Fluid method and the Discrete Phase Model. Firstly, the VOF model combined with adaptive mesh refinement is used to analyze how two process parameters, spraying pressure and putty viscosity, affect the atomization fan width and atomization fineness. High-speed imaging experiments are conducted to capture airless spray atomization images, demonstrating that the spray atomization morphology predicted by the VOF model matches the actual result closely. The spray atomization simulations further show that at a spray pressure of 25 MPa and a putty viscosity of 0.32 kg/(m·s), a limiting atomization fan angle of 30° is achieved and spray velocity, fan width and droplet size are jointly determined by pressure and putty viscosity. Increasing the pressure and decreasing the viscosity significantly improve atomization. Under high-pressure and low-viscosity conditions, the spray fan fully opens, breakup occurs earlier, and droplets are finer. To couple the VOF model with the DPM model, a VOF-to-DPM conversion mechanism is introduced. This mechanism seamlessly converts atomized droplets that meet a sphericity criterion into equivalent discrete phase particles, enabling the collection of atomized particle data, not only eliminating the need for costly and time-consuming experiments but also providing reliable initial parameters required for simulating surface film formation during spraying. Specifically, the region where droplets are converted into particles under the VOF-to-DPM mechanism is divided into multiple rectangular sampling zones to collect data on particle count, size, and mass flow rate. The spray atomization is then decomposed into a set of multiple flat-fan atomizer DPM frameworks composed of different combinations of initial parameters and spray directions, enabling efficient simulation of dynamic surface film formation under different trajectory strategies and surface geometries at a spray pressure of 25 MPa and a putty viscosity of 0.32 kg/(m·s). The dynamic film formation results indicate that, on different surface geometries, the coating film thickness distribution along the fan spread direction exhibits a bimodal pattern with higher thickness on both sides and lower thickness in the middle. At a standoff distance of 300 mm with reciprocating spraying at 2 m/s and a spray gun path spacing of 200 mm, the coating achieves the optimal uniformity, with film thickness maintained at 50±10 μm and a coverage width of approximately 400 mm. If the path spacing is less than 200 mm, excessive overlap occurs, causing abrupt changes in the film thickness distribution, degrading uniformity and reducing coverage. If the spacing is greater than 200 mm, the coatings from two adjacent paths become separated, leaving an uncoated stripe that requires a second pass, making coating quality harder to control. For local V-shaped surfaces and curved surfaces, the film formation results show that V-shaped surfaces are best sprayed along the generatrix direction, where spurious peaks in film thickness are fewer and quality is more controllable. Curved surfaces yield a smoother film thickness distribution when sprayed along the directrix direction, thus a spray-path planning strategy that moves along the directrix is recommended. Overall, trajectory planning should adopt a directionally consistent strategy according to the areal proportion of different surface types, which not only improves spraying efficiency but also helps control coating quality. The simulations demonstrate that the VOF-DPM coupled atomization and surface film formation model can accurately predict both atomization and film formation processes and they establish the key conclusion that process parameters determine atomization quality, whereas trajectory-planning strategies govern thickness distribution and uniformity, thereby providing theoretical guidance for automated spraying technology in rail coaches.
关键词
无气喷涂 /
涂料雾化 /
表面成膜 /
涂层厚度 /
计算流体力学 /
VOF-to-DPM
Key words
airless spray /
coating atomization /
surface film formation /
film thickness /
CFD /
VOF-to-DPM
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参考文献
[1] HUO L T, LIU Y, CHEN Z T, et al.Complete Coverage Path Planning Algorithm Based on Improved Biologically Inspired Neural Networks in Spray Painting[J]. IEEE Robotics and Automation Letters, 2025, 10(6): 5697-5704.
[2] XIA H F, HUO L T, SUN Q, et al.Spray Coating Coverage Path Planning Based on Multi-Layer Feature Aggregation RainbowNet[J]. Measurement, 2025, 253: 117710.
[3] 王飞, 何祖军, 苏贞. 一种船体分段漆料全覆盖的喷涂路径规划方法[J]. 计算机与数字工程, 2023, 51(12): 2867-2872.
WANG F, HE Z J, SU Z.A Spraying Path Planning Method for Full Coverage of Hull Segmented Paint[J]. Computer & Digital Engineering, 2023, 51(12): 2867-2872.
[4] 赵景山, 魏松涛, 赵东捷, 等. 超大作业空间涂装机器人研究进展[J]. 航空制造技术, 2023, 66(12): 46-58.
ZHAO J S, WEI S T, ZHAO D J, et al.Research Advancement of Coating Robot for Super Large Space[J]. Aeronautical Manufacturing Technology, 2023, 66(12): 46-58.
[5] 徐锋, 訾斌, 袁京然, 等. 喷涂机器人矩形喷枪建模分析与迷彩图案全覆盖路径规划[J]. 机器人, 2023, 45(2): 139-155.
XU F, ZI B, YUAN J R, et al.Modeling and Analysis on the Rectangular Gun of Spray-Painting Robot and Its Complete Coverage Path Planning for Camouflage Pattern[J]. Robot, 2023, 45(2): 139-155.
[6] 齐淑林, 郑权, 赵晨辉, 等. 基于涂层厚度模型的机器人喷涂轨迹规划研究[J]. 机床与液压, 2023, 51(15): 88-94.
QI S L, ZHENG Q, ZHAO C H, et al.Research on Trajectory Planning of Spraying Robot Based on Coating Thickness Model[J]. Machine Tool & Hydraulics, 2023, 51(15): 88-94.
[7] 陈方备, 王畅, 戴铮, 等. 空气雾化喷嘴喷雾特性实验研究[J]. 工程热物理学报, 2024, 45(3): 873-878.
CHEN F B, WANG C, DAI Z, et al.Experimental Study on Spray Characteristics of Air Atomizing Nozzle[J]. Journal of Engineering Thermophysics, 2024, 45(3): 873-878.
[8] 蒋仲安, 许峰, 王亚朋, 等. 空气雾化喷嘴雾化机理及影响因素实验分析[J]. 中南大学学报(自然科学版), 2019, 50(10): 2360-2367.
JIANG Z A, XU F, WANG Y P, et al.Experimental Analysis of Atomization Mechanism and Influencing Factors of Air Atomizing Nozzle[J]. Journal of Central South University (Science and Technology), 2019, 50(10): 2360-2367.
[9] 邵和, 王鑫, 李文璞. 内混式空气雾化喷嘴出口尺寸对雾化特性的影响[J]. 实验技术与管理, 2024, 41(7): 46-52.
SHAO H, WANG X, LI W P.Influence of Outlet Size on Atomization Characteristics of Internal Mixing Air Atomization Nozzles[J]. Experimental Technology and Management, 2024, 41(7): 46-52.
[10] 王松岭, 甄猛, 吴正人, 等. 压力对喷嘴雾化特性影响的数值模拟[J]. 机械设计与制造, 2020(3): 51-54.
WANG S L, ZHEN M, WU Z R, et al.Numerical Simulation of the Effect of Pressure on the Atomization Characteristics of Nozzles[J]. Machinery Design & Manufacture, 2020(3): 51-54.
[11] LILAN H Q, QIAN J B, PAN N.Study on Atomization Particle Size Characteristics of Two-Phase Flow Nozzle[J]. Journal of Intelligent & Fuzzy Systems, 2021, 40(4): 7837-7847.
[12] CHEN S M, CHEN Y, WU Z J, et al.A Hybrid Euler- Lagrange Model for the Paint Atomization Process of Air Spraying[J]. Processes, 2022, 10(12): 2513.
[13] YI Z Y, MI S Y, TONG T Q, et al.Simulation Analysis on the Jet Flow Field of a Single Nozzle Spraying for a Large Ship Outer Panel Coating Robot[J]. Coatings, 2022, 12(3): 369.
[14] KASHANI A, PARIZI H, MERTINS K H.Multi-Step Spray Modelling of a Flat Fan Atomizer[J]. Computers and Electronics in Agriculture, 2018, 144: 58-70.
[15] LIU M Q, HUNG D L S. Segment-Based Eulerian- Lagrangian Transition Method for Flat Nozzle Spray Atomization Simulation[J]. Engineering Applications of Computational Fluid Mechanics, 2024, 18(1): 2391448.
[16] 滕燕, 王譞, 李小宁. 高压无气喷涂涂料转移率的主要影响因素及规律[J]. 腐蚀与防护, 2012, 33(9): 753-756.
TENG Y, WANG X, LI X N.Main Influencing Factors and Laws on Transfer Efficiency of Paint for High- Pressure Airless Spraying[J]. Corrosion & Protection, 2012, 33(9): 753-756.
[17] 齐淑林, 郑权, 黄兆晶, 等. 机器人喷涂涂层厚度模型分析与试验研究[J]. 机械科学与技术, 2023, 42(9): 1423-1429.
QI S L, ZHENG Q, HUANG Z J, et al.Analysis and Experiment on Coating Thickness Model of Robot Spraying[J]. Mechanical Science and Technology for Aerospace Engineering, 2023, 42(9): 1423-1429.
[18] 杨春梅, 刘彤彬, 马亚强, 等. 基于响应曲面法的木材喷涂漆雾扩散角度与均匀度优化[J]. 林业科学, 2024, 60(6): 136-147.
YANG C M, LIU T B, MA Y Q, et al.Optimization of Paint Diffusion Angle and Uniformity in Wood Spraying Using Response Surface Method[J]. Scientia Silvae Sinicae, 2024, 60(6): 136-147.
[19] 陈诗明, 陈雁, 陈文卓, 等. V形面喷涂成膜数值模拟[J]. 表面技术, 2023, 52(6): 285-295.
CHEN S M, CHEN Y, CHEN W Z, et al.Numerical Simulation of Film Formation on V-Shaped Surface by Spraying[J]. Surface Technology, 2023, 52(6): 285-295.
[20] CHEN S M, CHEN W Z, CHEN Y, et al.Research on Film-Forming Characteristics and Mechanism of Painting V-Shaped Surfaces[J]. Coatings, 2022, 12(5): 658.
[21] LIU Y, ZENG Y, ZHAO X Y, et al.Analysis of Film Forming Law and Characteristics for an Air Static Spray with a Variable Position of the Plane[J]. Coatings, 2021, 11(10): 1236.
[22] CHEN W Z, CHEN Y, ZHANG W M, et al.Paint Thickness Simulation for Robotic Painting of Curved Surfaces Based on Euler-Euler Approach[J]. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2019, 41(4): 199.
[23] CHEN W Z, CHEN Y, WANG S Q, et al.Simulation of a Painting Arc Connecting Surface by Moving the Nozzle Based on a Sliding Mesh Model[J]. Coatings, 2022, 12(10): 1603.
[24] ANISIUBA V, MA H B, SILAEN A, et al.Computational Studies of Air-Mist Spray Cooling in Continuous Casting[J]. Energies, 2021, 14(21): 7339.
[25] WANG Y N, XIE X P, LU X H.Design of a Double- Nozzle Air Spray Gun and Numerical Research in the Interference Spray Flow Field[J]. Coatings, 2020, 10(5): 475.
[26] XIE X P, WANG Y N.Research on Distribution Properties of Coating Film Thickness from Air Spraying Gun-Based on Numerical Simulation[J]. Coatings, 2019, 9(11): 721.
[27] YANG G C, WU Z J, CHEN Y, et al.Modeling and Characteristics of Airless Spray Film Formation[J]. Coatings, 2022, 12(7): 949.
[28] 杨桂春, 陈雁, 陈诗明, 等. 无气喷涂涂料成膜建模研究[J]. 机械设计与制造, 2024(5): 219-222.
YANG G C, CHEN Y, CHEN S M, et al.Modeling of Airless Spray Coating Film Formation[J]. Machinery Design & Manufacture, 2024(5): 219-222.
[29] 刘爱虢, 李恒文, 于浩洋. 基于VOF-DPM模型的离心喷嘴中的燃油流动及雾化特征研究[J]. 热能动力工程, 2023, 38(11): 106-114.
LIU A G, LI H W, YU H Y.Study on Fuel Flow and Atomization Characteristics in a Centrifugal Nozzle Based on VOF-DPM Model[J]. Journal of Engineering for Thermal Energy and Power, 2023, 38(11): 106-114.
[30] TRAUTNER E, HASSLBERGER J, KLEIN M.Towards LES of Liquid Jet Atomization Using an Eulerian- Lagrangian Multiscale Approach[J]. Flow, Turbulence and Combustion, 2025, 115(1): 243-273.
[31] SUN Y Q, LI Y X, DREßLER L, et al. Multiscale Numerical Modeling of a Complete Spray Evolution Including Breakup of Liquid Jet Injection in Gaseous Cross Flow[J]. International Journal of Multiphase Flow, 2024, 170: 104655.
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