潮流能振荡式双水翼液态金属磁流体发电机理和仿生柔性水翼的研究

Tidal flow energy is very abundant in our country, with a potential power capacity of 14GW. It is very necessary to research deeply the tidal power generation technology..Oscillating foil tidal harvesting device may get a higher owing to no limited in the span length. It is more suitable to be installed in riverbeds and shallow water near the coasts. The project proposes an oscillating foil tidal power generation mechanism composed of dual hydrofoils. There is a coupling relationship between hydrofoils pitching motion and heaving motion, namely, the pitching motion of hydrofoil I is coupled with the heaving motion of hydrofoil II, and the pitching motion of hydrofoil II is coupled with the heaving motion of hydrofoil I. Thus, dual hydrofoils can achieve no dead point at the highest and lowest point. Based on the bionics principle, the project will adopt the flexibility hydrofoil to achieve the varying of angle of attack, and investigate its hydrodynamic characteristic to improve energy harvesting efficiency. Dual hydrofoils’ oscillating motion is coupled through hydraulic pipeline and liquid metal magnetohydrodynamic (LMMHD). Hydrofoils oscillating motions are converted into the LMMHD’s reciprocating motion. It cuts the magnetic-curves and produces electric power. This principle simplifies the electromechanical conversion mechanism, reduces equipment costs and improves power generation efficiency. The project will study the conversion efficiency and stability of oscillating hydrofoil tidal power generation system using LMMHD, and will investigate the power generation behavior under the complex coupling action of the flow condition, liquid metal turbulence and electromechanical factors (eddy current, magnetic field and induced current and so on). This novel tidal energy conversion principle will fit for the characteristics of lower average flow velocity and shorter high-velocity time in our country.

我国潮流能资源丰富，可开发功率达14GW。振荡水翼潮流发电装置，水翼展向尺寸不受限，可望获得更大功率。项目提出振荡水翼潮流发电机构由双水翼组成，双水翼升沉—俯仰运动耦合，即水翼1的升沉运动与水翼2的俯仰运动耦合，水翼2的升沉运动与水翼1的俯仰运动耦合，从而实现水翼运动至上下极限位置时，无运动死点。新型发电装置：1）液态金属为水翼实现运动耦合的介质，2）耦合振荡推动液态金属磁流体运动，切割磁场线产生感应电流，实现发电。该原理可简化发电机构，降低成本，提高效率。. 提出基于仿生学原理，研究具有柔性振荡水翼的水动力学特性，通过采用柔性水翼，实现变攻角，提高潮流能捕获效率。研究液态金属磁流体用于潮流发电的系统转换效率、稳定性问题；探索潮流参数、液态金属湍流与涡流、磁场、感应电流等复杂的耦合作用，及其对发电功率的影响规律。适合我国海域潮流高流速时间短、平均流速低的特点，适于近海浅水海域。

潮流能是一种无污染、储量巨大的可再生能源。振荡水翼作为潮流能发电装置的一种。液态金属磁流体发电技术应用于潮流能开发，可以取代传统海工发电装备中的增速装置以及转子发电机等。.主要研究成果包括：1）建立了弹簧-阻尼系统的能效图谱，搭建了Fluent-AMESim联合仿真平台，建立了基于液压联动系统振荡翼的水动力与运动的数学模型，揭示了液压系统参数对两个翼板运动-流场-力相互作用的影响机制。2）揭示了提高振荡翼捕能性能的机理，基于翼板结构、运动规律与流场速度提出了可摆动前缘板模型、非简谐俯仰运动模型与聚流板模型。3）基于翼型理论和儒可夫斯基公式，构建了常规振荡水翼和襟翼型振荡水翼的理论模型，导出了简单襟翼型水翼的迎角公式、襟翼型振荡水翼的升力公式，能够准确的反映襟翼对振荡水翼的水动力学影响。4）基于襟翼型振荡水翼理论模型，拓展得到简单襟翼型、格尼襟翼型、富勒襟翼型等三种襟翼型振荡水翼结构，并建立了相应的CFD数值模拟模型，分析获得了三种襟翼型水翼最优的升力系数、捕能效率。5）研制了简单襟翼型振荡水翼的拖曳水池实验平台，设计了振荡水翼的控制与数据采集系统，制作了简单襟翼型振荡水翼模型，实验证明襟翼型振荡水翼具有较高的升力和捕能效率。6）建立了液态金属磁流体发电数值模拟模型，揭示了液态金属磁流体发电内部多物理场耦合机制。根据内部哈特曼层电流回流情况，提出了改进通道模型，显著提高空载电压。7）修正了标准的湍流模型使其可应用于磁流体湍流流动问题研究，导出了液体金属磁流体发电的输出参数计算公式，基于电势法和诱导磁场法，系统分析工况，液态金属性质对磁流体发电机性能的影响，并探讨从内部机理上解释相关现象。.本研究发表学术论文15篇，其中4篇发表在一区刊物。申请国家专利4项。新型发电装置原理可简化发电机构，降低成本，提高效率，适合我国海域潮流高流速时间短、平均流速低的特点，适于近海浅水海域。