风力机叶片涂层耐风蚀性的耦合仿生研究

Sand and dust weather occurs frequently in the Inner Mongolia, wind erosion damage of wind turbine blades occurs seriously, improving the performance of the blade coating resistant to wind erosion has become a very urgent research tasks on protecting the stable operation of the wind farm. Coating biomimetic is an important research direction on the surface engineering. Populus euphratica is the only natural distribution tall trees at the forefront of the arid desert sand, nature endows with the inherent capacity of populus euphratica resistance to wind. Similarity is the basis of the bionic, the wind turbine blade anti-erosion coating and the shaped leaves of populus euphratica resistant to sand are highly similar in function resistance to wind, constraints and quality. Researching the anti-wind erosion mechanism of the shaped leaf surface of populus euphratica has an important guiding significance on coatings biomimetic design of wind turbine blade. The project uses the shaped leaves of Populus euphratica as study object, analyzing its surface topography, multi-layer structure and material properties, determining the surface coupling elements of shaped leaves of populus euphratica and coupling way, revealing the coupling mechanisms of the shaped leaves of populus euphratica resistance to wind erosion;studies on wind erosion characteristics and its mechanism of wind turbine blade coating, applying the coupling bionic theory and methods, implementing the coupling bionics of coating design for wind turbine blades. Simulating the characteristics of natural wind in Inner Mongolia, testing and researching the ability resistance to wind erosion of routine polyurethane coating sample and biomimetic sample. Project studies has theoretical significance and practical value for revealing the biological basis of the coupling mechanism of shaped leaves of populus euphratica ,improving the adaptability of the blade coating to the extreme wind climate in Inner Mongolia and promoting the engineering applications of bionics.

内蒙古沙尘天气较多，风力机叶片风蚀损伤严重，提高叶片涂层耐风蚀性能，已成为保障风电场稳定运行非常迫切的研究任务。胡杨是干旱荒漠风沙前沿惟一天然分布的高大乔木，自然赋予了胡杨与生俱来的耐风沙能力。相似是仿生的基础，风力机叶片涂层与胡杨异形叶表面在耐风蚀功能、约束、品质方面高度相似，研究胡杨异形叶表面耐风蚀机制，对于风力机叶片涂层仿生设计具有指导意义。本项目以胡杨异形叶为研究对象，分析其表面形貌、多层结构与材料特性，确定胡杨异形叶表面耐风蚀耦元和耦联方式，揭示胡杨异形叶耐风蚀耦合机制；研究风力机叶片涂层风蚀特性与风蚀机理，运用耦合仿生理论与方法，实施风力机叶片涂层耦合仿生设计；模拟内蒙古自然风沙特性，试验研究聚氨酯涂层常规试样和仿生试样的抗风蚀能力。项目研究对于揭示胡杨异形叶耐风蚀耦合机制的生物学基础，改善叶片涂层对极端风沙气候的适应性，促进仿生学的工程应用具有理论意义和实用价值。

内蒙古沙尘天气较多，风力机叶片风蚀损伤严重，提高叶片涂层耐风蚀性能，已成为保障风电场稳定运行非常迫切的研究任务。自然赋予了胡杨与生俱来的耐风沙能力，研究胡杨异形叶表面耐风蚀机制，实施风力机叶片涂层仿生设计，有利于改善叶片涂层的防护性能，提高叶片寿命并有效降低维护成本。. 本项目通过风电场调研，了解了风电场叶片损伤类型及其特征，重点分析研究了不同机型叶片的风蚀现状；采集了胡杨异形叶，从表面形态、微纳结构及环境特点方面开展了胡杨叶片耐风蚀耦合机理研究；按照风力机叶片涂层设计总体功能要求，合理选择胡杨叶片生物模本特征，研究建立耐风蚀仿生耦合模型，实施仿生耦合耐风蚀涂层结构设计、仿真分析。. 研究结果表明，叶片涂层实际损伤型式复杂多变，耦合损伤影响突出；沙粒冲击损伤和挟沙风疲劳损伤是叶片损伤失效的主要原因。观测分析表明，胡杨异形叶结构柔性大、表面蜡质层厚，叶面具有多层解剖结构，角质层较厚，栅栏组织发达，叶面细胞自愈合能力强，非光滑微纳结构与气孔的启闭，对风沙冲击有较好的缓冲作用，多元耦合作用使得胡杨异形叶具有极强的耐风蚀能力，表现出对沙漠极端环境的良好适应性。采用FLUENT软件，完成了风力机叶片流固耦合的建模求解过程；分析了粒子轨迹、流场速度分布、叶片与流场交界面的压力分布，计算了叶片表面的等效应力、总变形；明确了粒子冲蚀速度、质量流量和粒子直径对涂层风蚀磨损的影响规律，获取了叶片涂层的平均冲蚀率、涂层平均薄化量、最大冲蚀率。运用仿生耦合设计方法，开展了添加SiO2纳米粒子仿生聚氨酯涂层设计与制备，完成了风速、沙流量及沙粒粒径三因素风蚀磨损试验，初步结果表明，仿生涂层设计能够改善其耐风蚀性能。项目研究探索了胡杨异形叶耐风蚀耦合机制的生物学基础，为风力机叶片涂层可靠性设计、高性能制备提供了有效的理论支撑。