卡门涡街作用下利用压电效应实现波浪能发电的机理研究

The reciprocating motion of ocean wave is very slow, which makes it difficult to convert wave energy to power with high efficiency. Based on this background, this project mainly solves the following several key technical problems encountered in the power generation from ocean wave energy using the piezoelectric effect under the action of Karman vortex street. (1) Using the modern theory, method and technology of numerical calculation, special 3D numerical wave tank can be established to realize the numerical simulation of ocean waves, so that the wave forces applied to the flexible piezoelectric generation device (FPGD), as well as the complex flow field surrounding the FPGD, can be solved. (2) The mathematical model of FPGD can be established by multi-physical fields coupling analysis software. By the coupling analysis in fields between fluid and piezoelectric (structure and electric field), the structural optimization design of FPGD can be carried out. (3) A more ideal wave tank is built to test the power generation performance of FPGD. The wave machine in the tank can output controllable regular wave. The wave absorbing system can better weaken the incident wave and reduce the reflection of rarefaction wave. (4) After the optimization design, the performance of FPGD power generation is higher than that of the similar foreign reported samples.

海洋波浪具有超低速往复运动的特性，这给波浪能向电能的高效转换带来困难。本项目以此为背景，重点研究卡门涡街作用下利用压电效应实现波浪能发电的机理，内容包括：（1）利用现代数值计算理论、方法和技术建立专用的三维数值波浪水槽，实现波浪的数值模拟，得到柔性压电发电装置（FPGD）所受到的波浪力及其附近的复杂流场；（2）利用多物理场耦合分析软件建立FPGD的数学模型，进行流体—压电（结构—电场）等多场的耦合分析，并对FPGD的结构进行优化设计；（3）建造一个较为理想的适用于FPGD发电性能测试的波浪水槽：造波机能够输出可控的规则波，消波系统能够较好地衰减前方来波并减少余波的反射；（4）优化设计后的FPGD，其发电性能较国外同类试样要有所提高。

本项目围绕卡门涡街作用下利用压电效应实现波浪能发电的机理展开研究：（1）数值水槽的建模及分析，包括单圆柱绕流和串列双圆柱绕流卡门涡街的三维数值模拟，以及三维波浪的数值模拟；（2）压电俘能器采用了悬臂梁式结构，其建模与分析包括双晶片悬臂梁式压电传感器的有限元分析，压电悬臂梁俘能器输出特性仿真分析，压电双晶梁的电气阻尼特性分析，以及主动式压电俘能电路的研究；（3）基于压电效应利用流体发电是一种流体—结构—电场三场耦合的分析，同时也是需要进行压电分析的特殊流固耦合问题，研究内容包括均匀流条件下压电海藻的发电特性分析，波浪作用下压电海藻的发电特性分析，以及卡门涡街作用下压电鳗鱼的发电特性分析；（4）加工制造了小型水槽和风洞两套试验装置，可以观察出流体在钝体绕流时产生的卡门涡街现象，并基于此现象测试柔性压电发电装置的发电性能。